Conference 7.286::home_work

    I just finished installing one yesterday which I bought from Sears
    last fall on sale for about $70.  It included an adjustable thermostat
    control.  Its a little noisier than I expected when outside of the
    house.
    
    Mine mounted on the roof and required cutting a hole through the
    shingles, tar paper and sheeting.  It is a self flashing unit, so
    you just slip it between the shingle with some tar goop (not included)
    and fasten it down.  The electrical consisted of running a 120v
    line from an existing circuit to the fan.  I put a regular light
    switch in an upstairs closet so I can turn it off in the spring
    and fall when I might enjoy a little heat.
    
    The only bad part was having to climb on my roof which is a 11/12
    pitch.
    
    Tom
    

    A few years ago, I put a ceiling fan in the upstairs hallway of
    my gambrel - it's great. The fan cools the house in two ways; it
    pushes hot air out of the attic, and pulls fresh air into the living
    area. It's a 24-inch model, which is quite sufficient for our 1600
    sq.ft. of living space.
    
    I decided against a thermostat. I turn on the fan around 3:00 PM,
    with just the upstairs windows opened, because at that point the
    upstairs is usually hotter than outside, but the downstairs is still
    comfortable. In the late afternoon the downstairs windows are opened.
    On uncomfortable nights we keep the fan on low and strategically
    open windows so that there is a constant breeze in the bedrooms.
    Even if no one is home to turn it on at the right times, within
    ten minutes it will make the house livable.
        
    The fan came with a two-speed switch, but I replaced that with a
    continuously variable fan control (looks like a light dimmer, but
    may be rated for heavier load) so that we can adjust it to run quietly
    enough for sleep.

    I also decided to cut a full hole in the ceiling, instead of following
    the instructions that came with the fan (cut out the sheetrock,
    sit the fan above the ceiling joists with the supplied venturi cut out
    to nestle into the joists, and finish off with an automatic ceiling damper).
    I mounted the fan in a frame that drops into the ceiling opening.
    In the winter, I replace the fan frame with an insulated frame.
    I use the same opening for the odd occasion when I want to get into
    the attic (which is just a crawl space).
    
    The only caveat with using such a fan - make sure you have enough
    venting space in the attic to allow proper air flow. The recommended
    minimum, I believe, is twice as much venting area as the opening
    of the fan.

    
    I've lived in houses with whole-house fans, and concur: they're
    great. They can cool down a summer-hot house in no time.
    
    My problem is that my current house is a contemporary, without an
    attic in which to mount the fan. 
    
    Does anyone have suggestions as to how to get the same effect?
    

    I am going to put one of those whole house fans in the hall upstairs in
    my split.  My question about the venting is this: This house is brand
    new, has two louvered openings at either end of the attic, and is
    vented allong the (soffets? - is that the right word? - the part where
    the roof meets the wall at the outside overhang - there are vents all
    allong that part of the structure).  Is this enough venting? - also how
    much power does the unit need? - is a dedicated fuse necessary? 
    
    I will do the same, cut the joists etc.  Sounds neat what you did
    though, you say that you can lift the unit out and get into the
    attic that way?  I would guess you have a long wire running to it
    then eh? - much easier that emptying the closet to get up thru the
    tiny opening there...
    
    							.dave.

    I think it's `soffit', but you have the right idea. Soffit,
    ridge and louvered venting all contribute to attic ventilation and
    can be counted when you determine the venting needs for your fan.

    More on adequate venting...I think the `book' (wish I could remember what
    book that was) said to provide two_times_the_fan_size of *free* venting
    space. That is, for a 24-inch fan, if I cut two 24-inch round holes
    in my attic, I would be guaranteed enough venting. Of course, real
    vents have louvers or screens that further constrict air flow, so
    the safe rule was to provide four_times_the_fan_size of actual venting.
    I was short of that, but I didn't want my house looking like a wedge
    of swiss cheese, so it tried it with the existing venting (about
    three_times...) and it seems OK (no toasted fan motors).
    
    As far as power, each fan should have its requirements on the box,
    but I recall that it wasn't very much, and I have it hooked into
    a circuit that also services two bedrooms and a bath, with no problems.
    
    To bring power to the fan, I got a length of heavy duty braided
    wire (for flexibility) and terminated with one of those plugs that
    locks into the receptacle with a small twist. I put the receptacle
    on a rafter near the fan. That way, I can move the fan out of the way
    to get into the attic, and also remove it in the winter.

    Need a sketch? Send mail.

    Re power requirements, many fans come with a table which lists air
    flow, motor hp, and rpm.  Note that air flow is often stated for
    0 back pressure (i.e., free air movement without restriction).
    Estimate the interior volume of the space you want to ventilate
    (Not necessarily the volume of your home since you may plan to
    vent the first or second floors but not both at the same time.)
    and how often you want to exchange the air.  The table should 
    provide you with several options for a given air flow based on rpm
    and hp.  
    
    If you have a motor available, it may be usable.  Depending on how
    much volume you need to move, fan diameter, etc., 1/4 or 1/3 hp
    may be entirely adequate.  You'll need to match pulley diameters for 
    motor and fan shafts to obtain required fan rpm.  We did this with a 
    Dayton unit we installed several years ago - it came with a universal 
    motor bracket, we calculated pulleys needed, added a belt, and were
    in business.
    
    Check other models depending on your needs.  Often the difference
    among similar diameter units is the blade pitch.  Greater pitch
    usually requires more hp but moves more air at slower speed.  Slower
    speed is often quieter.  

    	The house that I am buying has no roof vents.  A roofer told
    me that I should have two vents installed to prevent heat build
    up under the roof.  Are the roof fans being discussed here the same as
    a roof vent?  I would rather put in a vent with a fan to get some
    summer cooling.  
    					=Ralph=
    
    	The first of many naive DYI questions.  
    	
 

    A roof (or attic) fan is not a substitute for attic venting. The
    purpose of attic venting is to prevent moisture buildup - if done
    properly, it will also help reduce attic heat in the summer.
    A fan will help air circulation, but you need the vents too.
        
    Most new homes are built with two kinds of attic venting - gable
    or ridge, and soffit. A gable vent is a louvered vent, located high
    on a wall in the attic. A ridge vent is a long strip that runs along
    the ridge of the roof. Soffit vents are located in the overhang
    between the roof and outside walls (the soffits). A combination
    of gable and soffit venting, or ridge and soffit venting, allows
    hot air in the attic to escape from the high vents, replaced by
    cooler air sucked in the low vents, thus promoting natural air
    circulation in the attic.
    
    Attic venting can be enhanced by the addition of an attic fan, which
    draws out the hot air more quickly. A gable fan is mounted behind
    a gable vent on an attic wall. A roof fan is mounted over a hole
    in the roof, and has a metal cover over it to protect against the
    elements. Attic fans do not usually cause air to move in the living
    space below.
    
    Whole house fans are mounted in the ceiling below the attic, and
    pull air from the living space into the attic. This type of fan
    can serve the same purpose as an attic fan, because as it pushes
    house air into the attic, the hot attic air is expelled through
    the attic vents. It also causes air movement in the living space,
    as outside air is pulled in through windows to replace the air
    exhausted into the attic.
    
    If you are going to install an attic fan, you must also supply other
    venting to allow fresh air to enter the attic. I would think that
    the easiest way for a new DIY'er would be a gable fan at one end
    of the attic and a louvered vent at the other end (no roof cutting).    
    This would probably be the choice if you future plans include central
    air conditioning.
    
    For a whole house fan, to also circulate air in the living space,
    put a louvered vent at each end of the attic and put the fan in
    the ceiling of a centrally located hallway.
    
    To determine how much venting you need, see previous replies.

    Re .3:
    
    How about a roof mounted attic fan? You could dress it up with some
    fancy louvered wood work on the inside, replaced with some fancy
    insulated wood work in the winter.

One note of caution regarding whole-house fans. Many towns have regulations/
laws regarding their installation or even if they allow them at all. The key is
that if you have a thermostat, it must have a safety cutoff so that the fan
shuts off above a given temperature. The reason is that if you have a house
fire the fan will turn on and very nicely ventilate your house - perhaps a 
little more than you desired!

Mark Parenti

    I use a quick and dirty method of installing a cooling fan for my
    upstairs. I have a attic opening in my upstairs hall (about 27"x27").
    I build a frame that fits in the opening and lay a multispeed 24"x24" 
    floor fan in it. Then as in a previous reply I just manually turn
    it on. I've been using this for the last 10 years. Works great.
    
    dave
    
     

    RE: .10
    
    	I saw a thermal cutoff at SPAGS in the Electrical dept for a
    few $, that opens when a certain temperature is reached.  Not having
    one on an attic fan is a little "dangerous"
    

    
    re: .12
    
    About the thermal cutoffs...They (at least used to) come with the
    Sears whole house fans.

                                                      - Rich

    I installed a whole house fan last fall. I have the louvered vents
    at the ends of the house and they are too small. What is the best
    way to add some passive venting? Should I cut 42 million soffits,
    should I retrofit a ridge vent? Any and all suggestions are welcome.
    
    Thanks,
    Paul
    

    Re .14:
    
    I watched roofers put a ridge vent on my neighbor's addition the
    other day. After shingling, they just placed the vent over
    a long slit opening left at the ridge, and hammered it down. Retrofit
    installation seems to be a matter of slicing the top off the ridge
    and anchoring the vent.
    
    On the other hand, I make it a rule to leave the roof alone unless
    there are no other options. How about bigger louvered vents? Space
    allowing, it shouldn't be hard to frame in a larger opening and
    put in a larger vent, two side by side, custom made, etc.

    I put a ridge vent on a house which previously didn't have
    one.  We removed the top row of shingles and cut about 1 inch
    off the top of the plywood on each side, using a circular saw.
    This left about a 3 inch opening, since the plywood wasn't 
    touching at the top.  We then nailed down the ridge vent and 
    put silicone or something over the nails.  If you do it make sure
    you cut away only as much of the shingles as you have to so that
    the vent will cover the shingles on both sides of the house.
    We did it about a year ago and there haven't been any leaks yet.
    

    
    This never got answered in the note on whole-house fans, so I
    thought I'd try again.
    
    The typical whole house fan pulls warm air from the main living
    area of the house up into the attic and out whatever ventilation
    is present in the attic. Cool air is pulled in through open 
    windows, with very good results.
    
    This is all well and good if you have a traditional home with
    attic or crawlspace.
    
    My problem is that I've got a contemporary, with no attic.
    Has anyone seen whole-house fan installations for situations
    like mine where there is no enclosed space overhead into which
    to ventilate?
    

    I haven't seen this anywhere, but it would be my approach if it
    were my house.
    
    Use one or more of those mushroom-looking fans
    that mount on the roof. Finish off a square opening from
    the ceiling, through rafters and up to the roof sheathing. Cut the
    sheathing only enough to accomodate the fan. On the other
    side of the opening (approximately flush with the ceiling),
    finish off with a louvered wood insert, mounted in such a
    way that it is easily removed. During the heating season, replace
    the louvered insert with an insulated plug that tightly seals the
    opening.

    
                               --------
     Summer                   /        \  <-- fan
                             /          \
                               |      | 
             --------------------    ---------------  <-- sheathing
              * * * * * * * * |        | <-- box between
             * * * * * * * * *|        |* * *  rafters
             ------------------        -------------  <-- ceiling
                             `- \ \ \ \ -'  <-- louver

    
                               --------
     Winter                   /        \
                             /          \
                               |      | 
             --------------------    ----------------
              * * * * * * * * ||* * * || * * * * * *
             * * * * * * * * *|| * * *||* * * * * * *
             ------------------|* * * |--------------
                             `----------'  <-- insulated plug

When I put a new roof on our place, I asked the Merrimack NH building 
inspector about powered roof vents/fans and he said that Merrimack codes 
didn't allow for them. However, the continuous ridge vent was approved.

When the ya-hoo who we bought from built on the family room, his 
contractor covered over the gable vent on that side. Needless to say, 
the moisture buildup was enough to delaminate the 3/8 sheathing. With 
the ridge vent and soffit air intakes, the roof/attic area is well 
ventilated, and is so far keeping the house cooler (maybe it's my 
imagination :-) )

The bottom line is the ridge vent certainly costs a lot less to purchase 
and less to operate...it also works year-'round.


My $.02...for what its worth...

Chris

    PRAISE:
    
    A ridge vent will keep the attic much cooler than soffet or louver
    vents because it is at the peak of the roof where the hottest air
    accumulates.  I had "adequate" ventilation area, but wanted to add
    more for a whole house fan.  When I put in a ridge vent the average
    daily temp. dropped by 20 degrees!
                                     
    CAUTION:                         
                                     
    If you decide to retrofit a ridge vent there are a couple of things
    you should be aware of.          
                                     
    One is that if you use the circular saw to cut through the asphalt
    shingles you will make a mess in the attic.  I would suggest putting
    drop cloths over any thing you have stored in the attic before cutting.
    I didn't know this when I did mine, and had to vacuum-up tons of
    asphalt chips.                   
                                     
    Two is that a ridge vent may allow soot from your chimney to come
    into the attic in the winter.  I discovered this "feature" this
    past winter when my furnace was burning dirty. I will put drop cloths
    over everything up there before next winter.
    
    BOTTOM LINE: I would put in a ridge vent again if I had it to do
                 over again. 
                 
    BTW I used a gable fan mounted on a hinged wooden frame over the
    attic "hatchway" as my whole house fan.  The cost was about
    1/3 of a whole house fan and yet the gable fan's volume was correct
    for my needs!                      
                                     
                                     

re .-1

One word of caution about using a 'mushroom' fan, however. I helped my 
father install one that is supposed to be for an enclosed attic. As it 
turned out, the fan, when running at it's normal speed was *VERY* noisy.

In fact, it was so noisy, he dosen't use it anymore even after trying to 
reduce the motor speed. Something to do with the pitch of the fan 
blades. You need a large, slow moving fan...not a high-speed whiner...

    Check the latest SEARS sale catalog - they have their better
    ceiling-mounted whole house fans on sale for around $220. It comes
    with a wall-mounted thermostat control. An option that you can (and
    shoud get) is what they call a FIRESTAT - it mounts in the attic
    and shuts off the fan if the temperature in the attic gets too high.
    The nice thing about this particular fan is that you don't have
    to cut any joists - you simply cut slots in the fan housing and
    set it on top of the joists. This particular model is supposed to
    be very quiet - the blade is belt driven and the moter assemply
    is mounted on rubber bumpers ( I think ).
    
    There is another alternative if you want whole-house air circulation.
    SEARS also has a window-mounted whole-house fan with a thermostat
    that can be mounted anywhere in the house ( it's wireless ). THis
    way, you can put the fan in a window on one side of the house, open
    the windows on the other side, and pull air thru. THis one is also
    on sale for around $130.
    							Bruce
    

    
    re: .19
    
    Will the window-mounted fan fit in casement windows? The trend in
    windows these days seems to be toward casement type, while most
    window mounted hardware/appliances is still oriented towards sash-
    type windows.
    
    Thanks.
    

>    A ridge vent will keep the attic much cooler than soffet or louver
>    vents because it is at the peak of the roof where the hottest air
>    accumulates.  

In general, you need both soffit vents _and_ ridge or gable vents.  Making a 
hole at the top of the roof for the hot air to get out doesn't do much good 
unless you have some ventilation lower down for cooler air to come in and 
replace it.

Paul

Discussion of ridge vents now started in 182.0.

    I'm considering buying a "whole house fan" - one of those units
    that vent through a ceiling into the attic.  They're on sale through
    the Sears catalog and I've heard good things about them (...as good
    as air conditioning in this part of the country..., etc.).
    
    My attic has loose, blown insulation in it (the type that looks
    like lint).  Attic ventilation seems adequate - two of those vent-type
    windows on each side of the house.
    
    Question:  Will the "whole house fan" end up blowing around all
    that insulation in my attic??? -- I have visions of the place looking
    like a lint blizzard.
    
    Any feedback will be appreciated.

My attic has bats with 6" of blown insulation on top.  I had that concern
also but I did not seem to run into any major problems.  A little stuff
around the fan itself got swirled around but the rest of the attic
stayed pretty calm.

-peter

    My neighbor installed a fan of that type with gable louvers on each
    end of his house....there was not enough "venting" and the air tries
    to push into the electrical outlets in the house!! His "fix" was
    to install full ridge vents.
    
    hope this helps
    
    canuck "cut twice still too short"
    

    Thnaks for the repsonses: re: (.1) - the blown insulation thing did 
    concer me - it's reassuring to hear that it stays put.
    
    Re.: (.2) (not enough venting with just the gable louvers?): I'll
    look into going the extra ventilation route (full ridge vents seem
    that it might be a significant, and costly, "fix" - I'll check it
    out, though.  
    
    I wonder if insufficient venting would stretch my house to 3 stories 
    (eg. lift the roof) or whether it would cause my roof shingles to 
    stand straight out when the fan is going. (just an attempt at humor!).
    
    

    In view of this note and others that sing the praises of fans 
    and my kids complaints about how hot the upstairs is
    I'm considering putting in a whole house fan.  What about the noise?
    Are they loud enough to be a disturbance or prevent normal sleeping?
    
    Thanks,
    
    George

    Re .3  Ridge vents generally come in 10 ft lengths and are about
    $16-$18 depending on the finish (mill, painted white or brown).
    If you are up to doing it yourself (if your roof pitch isn't to
    steep) it is not hard to do.  The type of vent I used (from Sommerville
    Lumber) requires 2 end plugs (<$1) as well or if you want longer than
    10 foot runs you can buy couplings (about a buck).  I have had the
    vents in since '81 I think and have not seen a drop of water or
    a flake of snow.  As someone mentioned previously, be generous with
    the roof cement.  I may still have a copy of a Globe article about
    how to install the vents.  I believe Popular Science had an article
    a couple of years back also.
    
    Marty
    

    RE: If you do the work your cost is low:
    
    Thanks for the info. - I'm surprised at how low the cost really
    is.  One catch (as far as I'm concerned), I would be unable to do
    the work myself - I'm useless at any height greater than 6 feet
    (afraid of heights).  I once considered having hundreds of yards
    of loam delivered to my house and dumped against its side so that
    I would only have to walk uphill to attach a television antenna.
    My wife wanted no part of this approach and I had the antenna
    professionally installed.
    
    It's not the height that worries me as much as it is the certain
    fall.  Any ideas as to how much it would cost to have the ridge
    vent installed - I know this contradicts the DIY creedo but I have
    to draw the line at heights.
    
    On the matter of noise levels, I've heard that the level depends
    upon the manufacturer of the fan (ie. actually, the design of the
    fan) and the speed at which it is operated - many have variable
    speeds - it's quieter at low speeds.  Anybody have more info. on
    the noise levels?

    
    I was a little concerned with the noise when I first installed my
    whole-house fan. As a result, I replaced the two-speed switch the
    one that is continuously variable. 
    
    Suprisingly, even when the fan is on high (hot, humid nights) the
    noise quickly fades into the background. I have never had any
    complaints about it keeping anyone awake. In fact, I am convinced
    that it has helped mask out the annoying barking of a neighborhood
    dog, which has kept me awake on many summer nights.
    
    My fan is direct drive. I have heard tha belt driven fans are quieter.
    The belt is supposed to isolate motor vibration from the fan blades.
    The reduction factor of the belt also allows the motor to operate
    at high revs while the blades turn at low revs and a greater pitch
    to move the same amount of air. I would definitely investigate these
    allegations if I were of a mind to replace the current fan.
    

re. 5

I have a 24" direct drive and find the noise to be not objectionable at all.
I believe the biggest factor for noise is size of fan blades and speed.
Bigger blades, lower speed mean quieter.  I find the large amount of air
moving slowly to be minimally noisy (all things considered).  Think of it
like pink noise, it's not really loud so the brain absorbs it as background
noise and soon you don't even realize it's there.

-peter

    
    Since Sears is being mean to me and not sending me their sale catalogs
    anymore, (probably couse I finally paid off their bill), what is the
    style and price of the unit(s) on sale?  I'm getting really tired of
    having to use a stupid window fan to sleep.
    
    						.dave.

    Snears isn't being mean to you... they're doing you a favor.
    

    I have a 36" Emerson.  Its belt drive.  Its noisy.  Its good. But
    you have to use it smartly.  NOT during the heat of the day as it
    will suck the heat into the house.
    In the morning we close up the house to conserve the cool air. 
    At night we turn on the fan when the outside is cooler than the
    inside.  Can NOt be used to vent the attic during the heat of the
    day.  Need attic fans for that.
    Also have blown attic insulation.  doesn't appear to be affected.
    ed
    

    The previous owner of my condominium has installed a ceiling fan
    in the living room, and it appears that the power line to the fan
    runs directly to the power box. I would like to install a wall
    switch, and I think that I have identified the proper power line
    in the area above my suspended kitchen ceiling. Is there a way to
    tell if this is the proper line without cutting it ? 
    
    ---Dennis

    I believe there's a device that may be called a 'tong ammeter' which
    senses AC current in a line by induction (the 'tongs' form a loop
    around the line, creating an inefficient but adequate transformer).
    You could try that (after turning the fan on, of course).  It might
    be necessary to separate the two leads and place the tongs around
    one, however.
    				- Bill
    

    Know abybody with an inductive ammeter? It's head loops around the
    wire in question, and the magnetic field from the current flow is
    translated into a current reading. I see plant engineering people
    using them all the time.

    To use an inductive ammeter you will have to separate the two wires
    and only loop the meter around one of them, otherwise the
    electromagnetic fields of the two wires will cancel each other out.
    
    I've usually been able to tug on the wire while someone watches
    the inside of the electrical box for movement. This all depends
    on staples, length of run, and accessibility.
    
    Nick

    why bother sears sells a remote unit in their catalog that involves
    just attching it to the existing switch in the fan.  Sounds like
    a lot less work.

	I'd like to install a whole-house fan, but have no attic, just
	a wedge-shaped crawlspace running the entire width of the house
	behind the second floor knee-wall (cape).

	I'd like to try mounting a fan vertically in this knee-wall
	just above the stairway, and add triangular vents at both ends.

	Any ideas, cautions??

                 //
                //
	       //|
	      // |
	roof //  | <- knee-wall                       second floor
	    //   F                                      hallway
	   //    A                          up
	  //     N                    coming
	 //      |          | stairway
	//       |          v
       //-----------------------------------------------

    
                         ..Not an answer to 170.23..
    
    I was wondering where I could get the parts to create my own attic
    fan.  I want to have a belt driven unit with a 30-36 inch fan on
    a variable speed switch.  Is there anywhere that actually supplies
    this type of unit?  
    
    I don't want to get a sears fan - looks really cheap.
                                                
    						.dave.

    That sounds like an interesting idea, do you have any more information
    on this switch (ie. catalog page, #, etc .) 
    
    Thanks,
    
    ---Dennis

    It was in the summer catalog under cealing fans.  The control unit
    looks just like the one we use on the tv.  dont' remember the price.

    Is there some reason why you can't run a switch leg from the fan?
    Then the location/identification of the power lead wouldn't matter.

	  POWER				________________ F
	_______________________________/                 A
	________________________________________   _____ N
						| |
						| |
						| |
						| |
						| |
						| |
					      SWITCH

    I have had my fan installed for 3 years now, and find that the noise
    is not a problem.  As previously mentioned, it does mask other noises
    such as dogs barking, etc.
    
    I have batts of insulation, so I can't say anything about that.
    However, I did have a problem with insufficient openings.   Rather
    that get into the ridge vent, I installed soffit (sp?) vents.  These
    are round screens which are installed in holes that you cut in the
    overhangs, IF your insulation was correctly installed.  That means
    that there is no insulation right about the overhang.  I used a
    hole-cutting blade in my drill and just spotted the locations on
    16" centers.  Seems to work great.
    
    I have a cape with 2 bedrooms upstairs.  They get VERY hot during
    the day, so I just open their windows in the early evening, even
    if the outside air isn't as cool as I want it to be.  With the fan
    on, this pushes out the superheated air in the space between the
    ceiling and roof.  When the air cools down, I open some downstairs
    windows and clear-out the whole house.  
    
    Lee

    Well, I friend has a Graingers wholesale catalog that has about
    everything in it from air tools to zip lock bags (almost - atleast
    that covers a-z).  Anyway I will eventually order a 3 speed whole
    house fan that is 30 inches, dynamically balanced and belt drive.
    It comes with the switch.  The louvers are extra, and are about
    40 dollars while the fan is 250$.  Since this guy knows somebody
    that works there he can get a 20% discount from them, the total
    for a really nice whole house fan and the louvers is $250.
    
    They also have the recessed lighting I was talking about at 21$
    each before the discount.  
    
    						.dave.

    	re .25
    	Did you know that DEC also has an agreement with Grainger to
    buy things.  Works like this:
    	Show them your badge
    	Pay CASH (No plastic or checks)
    	get ???? for listed first lower price 
    (for example of price break, 1-9=$10.00, 9-20=$8.00, you pay $8.00)
    
    This is for any DEC employee across the US.

>    (for example of price break, 1-9=$10.00, 9-20=$8.00, you pay $8.00)


    eh?  is that new math?  is 1-9,9-10 the time of day (in 24 hour
    time)?
    
    						.dave.

        We  recently installed a whole house fan, and our experience is
        consistent with that of others in this note:

        Insulation does not get blown all over the place.

        The noise is not bad at all (even at full speed).

        It works!

        We have a Broan 24" direct drive unit (from Somerville  Lumber)
        which  seems  to  have an advantage in that it mounts along the
        length of a joist with good shock and  vibration  mounts.   The
        motor  is mounted right on the joist itself which seems to help
        with quiet(er) operation (the Sears units mount at right angles
        to  the  joist).   The Broan 24" unit will mount on 24" centers
        (drop-in) or 16" centers (minimal trimming of  the  fan  shroud
        and then drop-in). We also have a variable speed control (nice)
        and a thermostat (eh...).

        A suggestion for anyone who has or is considering a whole house
        fan:

                            Buy a cutoff switch!!!

        This switch is mounted near the fan in the attic and serves two
        very important purposes:

        It kills power to the fan when you are working in the attic.

        It will automatically kill power to the fan if the  temperature
        rises  above 185 degrees.  I shudder at the thought of an attic
        fire being ventilated by such a fan  (mine  is  rated  at  5100
        CFM).  At $8, a cutoff switch is cheap insurance.

        				-Roland

	I heard a cute story once about someone turning on their
	whole-house-fan without first opening any windows, and
	sucking all the soot and ash out of their fireplace and
	into the living room!

	I wonder if the negative pressure in a situation like this
	(in a very tight house) could break a picture window?

    I doubt that a whole house fan can do much damage to picture
    windows.  Ours slams some doors shut sometimes.  And when we
    forget to open the windows it does pull air down all the fireplace
    and wood stove flues.  We've never gotten any ash, but the smell
    is somewhat unpleasant.  By the way, I built a large box with a
    hinged cover, completely insulated, to cover my fan.  In the winter
    I close it up.  Also, if the attic is really hot I close it up also.
    I have the lid on a counterbalanced pulley system.
    
    Now I have a question.  The louver (is that what you call it?  The
    thing in the ceiling that covers the fan and has slats that fold
    up when the fan is on.) for our fan is all bent up.  I'd like to
    find a replacement, but so far haven't found a source.  Sears has
    one that is close, but I'd have to do some carpentry to make it
    fit.  The fan is a 30' fan.  I have not been able to find any
    brand name anywhere on the fan.  I don't have the measurements on
    me, but I could provide them.  Does anyone know a good source for
    replacement louvers.  Grossman's doesn't carry anything as big as
    ours.
    			- Vick

    Source for air handling products, they carry whole house fans and
    louvers along with all sorts of industrial products.
    
    W.W. Grainger
    
    They have locations all over the U.S., I don't know where your from
    but the MA locations are
    
    	428 University Ave. Norwood, 617-762-7375

    	31 Cabot Rd, Worburn 617-935-8808

    Many industrial hardware stores are distributors for Graingers
    
    Parker Hardware in Maynard will order anything you want from the
    Grainger catalog and they send their own driver there a couple times
    a week to pick up the orders.
    
    It is sales to the trades only, but you can always show your DEC
    badge and pay for the order in cash.
    
    Nick

   Graingers in MASS
   
   	Norwood		762-7375
   	Woburn		935-8808
   	Worcester	853-7300
   	Springfield	781-7525
   
   NH
   	Manchester	668-7161
   

    I am getting tthe 30 inch model (someday) - the louvers are 28 dollars
    (I think).
    
    						.dave.   

    >  The fan is a 30' fan... Grossman's doesn't carry anything as big as
    >  ours.
    
    I'm not surprised that Grossman's doesn't carry 30 foot fans.  :-)

    Here's my situation. I'll be putting in a whole house fan shortly
    using 2 3-way dimmer-type switches to control speed. It will be placed
    at the top of the stairs of our gambrel.
    What I would like to do is place the 3-ways at the top and bottom
    of the stairs.  had planned to do this myself but the wiring leaves
    me a little leary.
    I have 2 3-way switches controlling the light in the stairway
    and I planned on putting the dimmers in the same boxes (enlarged,
    of course). Would it be possible to use the same common wire
    that the current 3-ways use?
    I am trying to do this with as little effort as possible, so
    I figure with that wire going to and from where I need it to
    go, that save me a big headache.
    
    Thanks,
    John
    

Hmmm I bought a real fan speed control at a electrical supply house 
for like $15 2 years ago - is that 'uncheap?"
(used it to make my tank humidifier fan "variable-speed")

Interesting...

Our house has 2 dimmers on the same circuit.  It turns out that only one ever
works and the other must be completely on of completely off.

I've been saying for the last year and a half I should do something about it
but have been to busy doing MAJOR projects to find the 10 minutes it would
take to replace these.

-mark

    I've had instances where this might have been nice to do, but it's
    an interesting intellectual exercise to specify exactly how it
    should work - e.g. if dimmer #1 is all the way up and you dim the
    light with dimmer #2, then is dimmer #1 now "backward" (like a plain
    switch would be), so that turning it counterclockwise now increases
    the intensity?!
    
    And that's the easy case, think about it for intermediate values
    of #1 and #2.

    RE .6
    It's funny you mentioned that about the relative positions of the
    two dimmers.
    I stopped by a hardware store on the way home last night and was
    asking about this situation. He stated that dimmers are designed
    to always work in the same direction regardless of which one is
    turned on, however, if one was say up 3/4 full, and one was up
    1/4, when you reverse the situation, the fans' speed will be at
    whatever the current dimmer is set at. Outside of that, it'll
    work fine.
    
    John
    

    Back to the motor speed control part of the problem.
    
    There are basically two types of electric motors, those with brushes
    and those without. Those with brushes are commonly in things like
    kitchen appliances, drills, saws, other hand tools. These can us{
    simple light dimmer type speed controls- the squared up sine wave
    doesnt bother them a bit. The trigger speed control in a drill is
    exactly this tyoe of circuit (you can make a  variable
    speed controller by putting a dimmer in a box with a cord and plug)
    Of course you must make sure the dimmer can handle the power
    requirement of the motor, but since most dimmers handle 500 watts
    and that is equivalent to about 3/4hp that is usually no problem.
    
    The second kind of motor has no brushes- these are the induction
    motors and every  whole house fan, and most other blowers, I have
    ever seen have this tyoe of motor. They can only have spped control
    by frequency changing,- unreasonably expensive - or by changing
    the internal wiring of the motor. Some fans have two tor three speeds
    accomplished by having several leads come out of the motor and
    switching them to select one or two fixed speeds.
       
    Bottom line is I doubt you can use dimmer switches to co{trol your
    whole house fan.
    

    RE .8
    I wasn't planning on using a basic light dimmer. After reading note
    170 (esp. 170.2), I became interested in using some sort of variable
    speed control. Two, if possible.
    
    John
    

>    dimmers are designed
>    to always work in the same direction regardless of which one is
>    turned on, however, if one was say up 3/4 full, and one was up
>    1/4, when you reverse the situation, the fans' speed will be at
>    whatever the current dimmer is set at. Outside of that, it'll
>    work fine.
    
This makes no sense to me, either electrically or from a human interface
standpoint.

Are you saying that the fan somehow only "listens" to the last dimmer 
you changed?  (What if both get changed at the same time?) 

I don't think two 3-way dimmers on the same load will work under any
circumstances.  One dimmer with as many switches as you like, but not 
two dimmers.  If there is a way, I'd like to know about it. 

    What I was told, was that whichever one TURNED ON THE FAN controls
    the speed.
    Situation:
    Fan is off. Dimmer A happens to be set at 1/4 up. Dimmer A is pushed.
    (Fan is turned on by dimmer A) Fan is now at 1/4 speed.
    With me so far?
    At this point, only dimmer A controls the speed. If dimmer B is turned,
    NOT PUSHED, nothing happens.
    Dimmer B happens to be set at 3/4 up. Now dimmer B is pushed. Fan goes
    off. Dimmer B is pushed again. Fan goes on and is spinning at 3/4
    speed (what dimmer B was set at). Now dimmer B controls the speed
    and dimmer A has no effect.
    That was what the fellow at Aubeshaun (sp) explained to me.
    
    Perhaps these aren't the conventional 3-ways used with standard 3-way
    switches. Maybe they are not even 3 way! 
    I'm not electrical expert, but it makes sense to me that whatever
    dimmer turns the fan on, controls the speed. The other dimmer has
    no effect until it turns on the fan.
    Once I have this installed, I write again (new note), and let you
    know how it works.
    
    John
    

It seems like these are standard SPDT switches with dimmers...

                 dimmer1
                _#######_______________________
        switch1/                               \switch2
______________/ _______________________#######_ \______________
                                       dimmer2                #
power                                                         # fan
                                                              #
______________________________________________________________#

The dimmers may or may not have a connection to AC return, depending on how
they work.

Jim.

re .11:  Thanks for the clarification.  Sounds great, if only it works.  
I still don't see how it would work electrically.

re .12:  A step in the right direction, but it won't do what .11 describes.
Specifically, if switch1/dimmer1 is set to dim, one wire has 25% power and
the other has zero.  No conceivable setting of switch2/dimmer2 would send
more than 25% power to the fan, and .11 calls for 75%. 

I think switch2 needs to choose between the dimmed wire from switch1 and a 
full-power wire that bypasses switch1.  Putting the two dimmers on opposite 
legs, as .12 did, looks right.

It annoys me that I can neither design the right circuit, nor prove that 
it's impossible.  I'm usually pretty good at this type of problem.

RE: .13 RE: .12

Yes, it will work.  If you throw switch2, it switches out dimmer1, and switches
in dimmer2, which you can then adjust to 75%. 

...

But, you have to make sure that each dimmer is adjustable at each switch
station, no matter which way the switch at the other switch station is set. This
complicates things, but it's not impossible.  I think that you need to use at
least single throw double pole switches.  I'll leave the diagram as an exercise
for someone else. It's possible, but confusing. :-)

RE: 170.26 (Digital/Grainger agreement)

	Has anyone actually bought something from Grainger's 
by just showing their Digital Badge? 

	I went to the Grainger's in Worcestor, MA. to buy something
over the counter, but they would not sell anything to me just because
I had a Digital badge. They explained that they are a wholesale 
company and can only sell directly to businesses. They said they 
could get a PO (purchase order) from Digital and have me pay cash 
and then they would forward the PO to Digital with a balance of zero 
dollars. But first they would have to call Digital purchasing dept. 
for approval. So I said okay. Well, they called and purchasing said 
they knew nothing of the agreement and would not approve the purchase.
Then purchasing asked to put me on the phone and they asked me where 
I got this information. I explained to them it was in (this) notes 
file...that's when she told me I should verify my sources first! 
(Nothing personal guys!). I ended up walking out empty handed. 

	Does anyone know what the story is? Does such an agreement
exist? And if so, how does one take advantage of it? 

						/Glenn

I just called Parker Hardware in Maynard to check on the Grainger fans.  The
36" costs $253.52 and there are a couple of louvers to choose from for around
$40-$50.  This seems like a pretty reasonable price as the other places I've
looked go as high as $400.

From the several replies on Grainger, am I to assume that this is indeed a high
quality fan?  Is it direct drive or belt drive AND does it matter?  Somehow,
belt drive seems like it would be a better mechanism (or am I thinking about
turntables)?  Actually, I think the same principle applies...

-mark

    
    Allegedly, the belt drive decouples the motor buzz from the blades,
    which act as a great sounding board. It also provides the torque
    conversion necessary to drive a high-pitch blade at lower speed,
    which is also supposed to move the same air volume with less noise.

I'm making progress,  I've contacted Grainger's and they indeed confirmed
that if you show up with a DEC badge they'll sell to you for CASH.  The deal is
that they use DEC's account and they don't want any bugus charges.

Looking through their catalog I see several models of fan and am therefore
reasonable confused as to which model is for me.  I've got over 2500 square
feet to cool and from talking to a few stores, it sounds like I need a 36"
fan.  I believe shutters are extra on all of them but run around $40-$50.  In a 
VERY brief summary,

Emerson		30"	1/3 hp		6300 CFM		$197.33

Fasco		36"			8250 CFM		$247.90
[1]

Dayton		36"	1/3 hp		6500 CFM		$263.00
[2]			1/2 hp		8000 CFM		$292.18
			3/4 hp	       10800 CFM		$358.48

Dayton		30"	1/3		6500 CFM		$260.57
[3]

[1]	includes 3 speed switch
[2]	2 speed motor, 1 speed about $10-$50 cheaper
[3]	2 speed motor standard

One more question - is there an easy way to determine how much attic venting
you need?  Usually there are specs for that but Grainger's doesn't show any.

Does anyone have an address for Dayton?  I'll contact them for literature.

-mark

    We have a whole house fan mounted in the ceiling over the top of
    our staircase.  It has a set of louvers which open when the fan
    is on.  However now that it has gotten cold we can feel the cold air
    pouring in through the supposedly closed louvers. Any suggestions
    on how to winterize the fan?  We would prefer leave the fan in place
    and work around it.
    
    Carol

re: .29

	I took a couple of big boxes, turned them into one extra-big box 
by cutting and using tape, then lined the inside with plain old 
fiberglass insulation.  (Paper side out so it wouldn't catch on the 
corners of the fan.)   In the winter, I'd just drop the box over the 
fan.  Since we didn't use the attic for anything, it didn't matter that 
there was a huge box up there in the summer.  If you use yours, you 
might find the box a litte hard to store.

					>>>==>PStJTT

Or - get a piece of sheetrock (or a ceiling tile) cut it to size, ad 
drop it in from above

nail a 2x4 to the back so you can lift it off in the spring

    
    	I remember seeing a device in Practical Homeowner or one of
    those mags which had a seemingly clever solution to this (sorry
    I don't have the article or reference).
    
    	As mentioned in previous notes, the guy built an insulated box
    around the fan. He hinged the top and attached it to a weighted
    (bucket with rocks in it) pulley system. He then added just enough
    weight so that the cover stayed closed when the fan was off. When
    the fan came on, the pressure of the moving air was enough to open
    up the top and move the air.
    

    I have a problem that's 3-way/4-way switch related.
    
    Seems several outdoor lights are connected to multiple switches
    (at least 2, maybe 3 switches).  What makes it a real pain in the
    ass is that you can't see the lights that are switched from the
    location of the switch.  So you don't know if you're turning the
    lights are on or off.
    
    I've seen the switches with the neon pilot lights for around $5.
    But do these come in the 3-way variety?  If they do, does the pilot
    light on each switch light when the lights are on?
    
    Any suggestions from the electrical wizards on how to solve or
    get around this one?

    Phil

    My parents house has a three-way with a pilot lamp in the toggle.
    The pilot lamp is ALWAYS on (I think???).  Well, at least they I
    know they make them :-)
    
    mac

      The purpose of the pilot (neon) lamp in the toggle is to see the
    switch in the dark.
    
    -Jim
    

    RE: .16, .17
    
    I think what you're both referring to is a lighted switched.  One
    that glows in the dark.  The pilot light switches indicate when
    the light is actually ON.  Or am I imagining all this???
    
    Phil

    re: .18
    	Yes what I was refering to was a lighted toggle switch.  The
    other type that uses a pilot to indicate when the lamp is on may
    not be available in a 3-way.  If it is, you know it has got to be
    mega-priced!
    
    mac

                I have just such a beast in my house on the garage
        light. The switch in the kitchen has a lighted handle which
        lights when the garage light is on. The switch does cost more
        than a normal 3-way but isn't unreasonable when you consider the
        agravation it could save you (it should run about $10). They are
        hard to find (I didn't try Spag's) and even all the electical
        supply houses don't carry them!
                
                There is one potential gotcha in the system. The light
        MUST feed from the box that the lighted switch is in. The light
        is really a second (or third, or fourth....) light in the
        circuit and needs to have both neutral and switched hot in the
        box that it is in.
                
                I believe that 3-way switches are also available with
        separate bulbs (incandescent) that can be used in the same way.
        (I think the neon bulb in the switch handle looks MUCH better
        inside the living area.)
                
                /s/     Bob
                
                
 p.s.  I didn't even know that they existed until I moved into my house
        and found one in the kitchen. I had to replace it once in the
        ten years that I've lived here - the light died.

    Spag's doesn't carry the switch with the lighted handle.  They only
    have the type where there's a separate red pilot light.  It uses
    a double socket wall plate rather than a switch plate.
    
    -al

    RE: .20
    
>        There is one potential gotcha in the system. The light
>        MUST feed from the box that the lighted switch is in. The light
>        is really a second (or third, or fourth....) light in the
>        circuit and needs to have both neutral and switched hot in the
>        box that it is in.

	Are you saying that only 1 of the switches in a 3-way configuration
    can have one of these lighted switches?
    
    Also, anybody know a place that has these switches in MA or NH?
    

Funny you should ask, but I just installed a lighted 3-way last night.  
I bought it from SEARS, and it cost under $10.  ($7.99 I think). The 
toggle is clear and illuminated internally somehow with a neon bulb.  The 
real "goodie" is that the switch is lighted when it will turn the circuit 
on! Sounds exactly what you're looking for.

They also have illuminated toggle dimmers for 3-ways.  Believe it or not, 
you can have 2 of these dimmers controlling the same light.  It works too! 

fyi,
...bill

    As I recollect, an n-switch setup has exactly 2 3way switches in
    it and n-2 4ways between them.  Is this correct?
    
    If so, would the lighted 3ways still work as .23 claims, if they
    were one of the two 3ways in an n-switch arrangement (where n>2)?
    
    -joet

The entire network of 3-way and 4-way switches taken together determines
whether the switched loads (lights) will be on or off.  The network is
designed in such a way that the loads can be turned either on or off from any
of the switches, but that's a detail at this point. 

The important thing to note is that the "answer" is only "known" by the last
switch in line, i.e. the one electrically furthest from the power source. 
That "answer" can drive all the pilot lights and real lights you want (subject 
to circuit loading).  The intermediate "answers" which the other switches
along the way "know" don't do any good. 

The easiest pilot light to wire, then, is one that is located very near that
last_switch_in_line.  This wiring is so easy that some manufacturers do it
for you, and supply 3-way switch, pilot light, and appropriate wiring all in
one package. 

To power pilot lights that are located anyplace else, you need to run wires
to them, just as you need to run wires to the real lights you're powering.
Electrically, the only difference between pilot lights and real lights is
wattage. 

One way to build your own pilot light is to run those switched wires to an
ordinary outlet, and plug a night light into it. 

The above discussion applies to pilot lights that go ON to indicate that the
load is ON.  I don't know about lighted switches, which typically go ON when
the load is OFF, theoretically so you can find the switch in the dark. 

re .26

> This note is now discussing TWO types of switch pilot lights!

> The first topic deals with switches which light up when they are off, 
> ostensibly so they can be found in the dark to turn them on.  

Considering that .15 (the reply that restarted the discussion in this
topic) asked for information about what types of pilots/lighted switches 
are available, that's not entirely bad. 

If you (.26 or anybody else) feel strongly that these two discussions belong
in separate topics, go ahead and untangle 'em.  But my opinion is that the
discussions are sufficiently inter-related that they benefit from being
together here.  As long as everyone clearly states which type they're
talking/asking about, it shouldn't get too confusing. 

    
    I use a Patton portable whole house fan and it works great. I put
    in a window up in my bedroom and open a window in the other rooms
    in the house. I point the fan to blow out the window thus drawing
    air from the outside and cooling off every room this way. The fan
    moves 12,500 cubic feet of air a minute and the new ones have a
    25 year warranty on them. They go for $50 on sale to $80 regular
    price. I have had mine for 5 years now and have no complaints.
    
    As for the attic, I had ridge vents installed last spring and this
    has cooled the attic off tremendiously. I see no need for an attic
    fan with the ridge vents and my portable one that i use now.
    
    
    Dave

    Only 4 short months after my wife (.29) asked me to, I got around
    to making a box to cover the attic fan for the winter.  I used a
    one-inch think sheet of Koppers insulation (rigid foam), cut it
    into pieces and taped it together with duct tape to form the box.
    It fits nicely over the fan opening in the attic.  It's only been
    up for a day but we have noticed the reduction in drafts already.
    The insulation is very light, so it should be easy to take the box
    on and off twice a year.
    
    Marc
    

I took a different approach...the hole in the ceiling that held the
attic fan vent was nicely framed with molding.  So, I took a 3/4"
piece of plywood cut to the size of the hole, painted it, backed it
with insulation (reflectex), and built a hatch door.  It's held in with
2 hinges on one side, and a door bolt on the other.  In the summer, I
can remove the hinge pins and take the whole thing out.  Again, it cut
the drafts significantly.  (As far as heat is concerned, an attic fan
vent is simply a transparent hole through your insulation and out your
roof). 

I don't know of any specific National Electrical Code provisions about
dedicated circuits for fans.  So it's probably OK to add a fan to a 
circuit that serves other purposes as well, assuming that the circuit
has sufficient capacity for the fan. 

In particular, don't just connect the fan to a convenient nearby circuit
and hope for the best.  Add up the loads and make sure.

    
    But will the startup of the fan cause all the lights on the circuit
    to dim or flash??
    
    Phil

    Not in my experience. (House fan powered from bedroom circuit.)

This is probably a dumb idea - but that won't stop me from posting it.  Might
there be a possibility that there are enough people interested in fans (after
all, this IS the season to think about them), to do some kind of group purchase
and thereby get a discount?

I would think as little as 3 or 4 people could generate 10% or more off a price.

-mark

    To the contrary -- I think that it is a great idea.  Just looking
    at the number of people who seem to have put them in last year,
    we might be a ble to cut a deal -- or at least lessen the overheads
    involved in the process.   
    
    Moreover, the mutual commitment involved might mean that I get this
    thing installed before the first snows fall!
    
    Are there any other takers?
    
    	Andrew
    

    
    	I'm planning on installing one this year also
    					=Ralph=

    Count me in.  I was planning on buying one sometime this summer
    anyway.
    
    George

Ahh...  now we're making some progress!

Last year I went to all the trouble to look at a Grainger's catalog.  It looks
like DEC employees can get DEC's discount.  The problem is there are several
models and I have no idea which one is the one to get.  If I recall, the 2 
parameters were RPMs and diameter.  Naturally, the bigger the diameter and RPM's
the more air you can move.  However, if memory serves, it wasn't that straight
forward as one of the smaller models cost more than the bigger one.  
Unfortunately the catalog is back at work on my desk and I'm at home.

Does anyone have any input on this?

The other options I think are SEARS (and I just as soon stay away from them) and
lumber yards.  The latter seem to have periodic sales on random brands and none 
seem to be better than Graingers.  Now it turns out if we went there and got DEC
discount they probably wouldn't give us anything off, but at least we could help
each other make the choice.

-mark

    	Note 170 also has some information on whole house fans.  haven't
    had time to really go through all the replies but it seems that
    they do talk, at least a little, about cfm, speed, fan size etc, etc.
    
    George

    
    According to note 170.28 DEC employees CANNOT buy from
    Graingers. To have a hardware store make the purchase I
    assume that they would want at least 10% profit.
    Comparing the fans from Graingers and  the Sears catalog
    it seams that Sears better direct drive fan is exactly the
    same as the Emerson in the Graingers catalog but priced
    about $15.00 more. The sale price would probably be the same
    or better than Graingers.
    Has anyone had any good/bad experiences with this or a similar
    type of fan? For the price I'm considering going with this fan
    with variable speed and 12 hour timer. I have 1500 sq. ft. to
    cool and will go with the 30 inch as r.p.m. is only 510 @6300
    CFM which is not to much worse than some of the belt driven models.
    I noticed some people elect to cut the attic joists instead of
    mounting on top of them. What is the benefit of this?
    
    Thanks
    Len DiPinto
    

    I installed a Sears direct-drive fan in my previous house.  It
    had a temperature sensor that would make the fan run faster when the
    air was hotter (first turned on), then slow down as the attic cooled
    down.  It also had a wall-mounted thermostat for on/off control.
    Worked great!  But I haven't seen this model for several years.
    
    				Steve

I'm sure the reason you haven't seen the temperature sensitive model is because
they are now illegal (or at least should be!).  The problem is that if there is
a fire, the temperature sensor turns on the fan and fans the fire!

-mark

    Re: .36  [Corrected from earlier entry]
    
    I asked about that.  The model I installed also had a heat-sensitive
    link that would shut off the fan if the temperature rose above 130.
    
    I don't see a difference between a temperature-sensitive fan and
    a normal one in the case of a fire.  Both are going to draw
    air until something shuts them off.  I would hope that ALL whole-house
    fans have a high-temp shutoff.
    
    The big advantage of the model I had was that it ran fast at first
    and cooled off the house (and attic), then slowed down to a barely
    noticeable hum.  I couldn't understand why that style wasn't more
    popular.
    
    				Steve

    The heat sensitive link is required for UL approval.
    

    
    Its done!
    I installed the Sears(actually Emerson) 30" direct drive
    fan this past weekend. It sits on top of the joists and
    was fairly easy to install. It came with a firestat that
    mounts in the attic as a shutoff in case of fire and a
    variable speed switch. I added a 12 hour timer which fits
    in the same double box. The fan makes less noise than I 
    was expecting. I am very happy with it.
    
    Len DiPinto
    

    I have two schemes I'd like to open up for discussion
    regarding cooling down the attic as well as the house.
    
    I have a Garrison with about 5.5' of attic.  On each side of the
    attic is a 1' x 2' (approx) louvered vent.  That's it.
    
    Access to the attic is through a cut out in a bedroom closet.
    
    I'd like to  try to cool off the house and do it the simplest way
    so my plan is to take a 10" muffin fan ($1.00 tag sale)  and
    hook it up to about 3 feet of galvanized duct, mount it to one
    of the vents and pull the hot attic air throught the vent.  I assume
    the other vent will act as a supply.
    
    Anybody think it'll work?
    
    Also, I thought about taking the 24" regular floor fans and just
    resting it flat over the closet opening so it can suck air from
    the bedroom and blow it up into the attic.
    
    Whattya think?  

    
<    Also, I thought about taking the 24" regular floor fans and just
<    resting it flat over the closet opening so it can suck air from
<    the bedroom and blow it up into the attic.
    
	NO,NO,NO,NO,NO

	1)  They are not designed for use in a horizontal position.  Most
	carry warnings about not using in the horizontal position.  You 
	will definitely wear out the motor quickly, the blades probably 
	are not balanced properly, the draw will be reduced and worst of all 
	the additional drag on the motor can cause the motor and powercord
	to overheat, creating a fire hazard.

	2)  Cheap fans lack the proper shutoff in case of a fire.  This is not 
	a problem for floor fans in normal operation, because they are only 
	moving air around in a small area, not pulling it from all parts of 
	the house.

	3)  I doubt that you will see a noticable difference.  An attic fan
	moves a lot more air.  Attic fans are designed to be dropped into 
	24" opennings.  Buy one and use the floor fan to direct the fresh 
	air where you need it.  

	You will probably want to put the fan in a more central location, 
	unless you want all your clothes covered with dust, etc.

    Welllll....We put up a "hokey" attic fan last week when it was so
    unbearably hot, just to see if it would change our situation any.
    We have one 5K BTU window A/C upstairs, and when it's really hot,
    it just couldn't keep up with the load.
    
    This year, we took a 16" table fan and put it on a table in the
    attic, just in front of the vent at one end. We turn it on in the
    AM, and off at evening. The vent is about 12 X 18 inches, so I 
    wasn't sure if there would be enough air flow, or not.
    
    The result was not very quantiataive, as we didn't actually make
    temp measurements before / after. BUT....we did notice that the
    ceiling of the bedrooms remained cool to the touch, where they had
    been warm to the touch "before fan". Also, the A/C seemed to be
    able to do a better job of removing the heat that was there.
    
    Mind you, this is not a "permanent installation", and I don't advocate
    anyone else doing it, as the safety implications aren't nice (no
    thermal cutout in case of fire). However, I offer it as evidence
    that even a "small" attic vent fan can offer significant help in
    dealing with the heat. I will be installing a vent fan very soon,
    as a result of this experiment.
    
    Bill

    re: -2, -1
    
    Well, Thanks for the warning about the floor fan.  The sun creates
    enough heat without asking an overheating fan to contribute.  ;^)
    
    However, I think I'll try the muffin fan-out-the-vent, with a regular
    electric cord.  Since it was designed to exhaust hot air from CPU-type
    cabinets, I don't think the risk of fire due to overheating is
    very great. Do you?
    
    

As I understand it, the purpose of the thermal cutout switch isn't to keep
the fan from overheating and starting a fire; it's to keep the fan from
continuing to run in a house fire, contributing to the chimney effect and
making the house burn down hotter and faster. 

Seems to me that if the fan is big enough to make a difference in cooling
the house, it's big enough to make a difference in a fire.  And if it's not 
big enough to make a difference, why bother?

So the muffin fan is probably fine for an experiment, but if you start using 
it all the time, I hope you're self-insured. 

    Re: .36 and .39
    
      Why not get one of those turbine vents.  It's one of those that
    spins from the hot air leaving the attic.  You ill be amazed at
    how it will almost perpetually turn.  I installed one last year
    and was amazed at how much 'pressure' was in the attic.  While I
    was cutting out the hole in the roof to install it, most of the 
    sawdust was actually blowing back at me!  They cost around $20 at 
    Grossmans on sale and are definitely worth it. I had a severe lack 
    of ventilation in the attic prior to this so I installed this vent 
    as well as vents under the eaves.  I don't consider myself an expert
    on this by any means but I wouldn't consider an attic fan (or fan
    in the attic in your case) unless I wanted it to draw hot air from
    inside the house.  That is what they are designed for.  
    
    -Jim

>
>< Note 170.41 by HPSMEG::LUKOWSKI "I lost my A$$ in the '87 CRASH!" >
>
>
>    Re: .36 and .39
>    
>      Why not get one of those turbine vents.  It's one of those that
>    spins from the hot air leaving the attic.  You ill be amazed at
>    how it will almost perpetually turn.  I installed one last year
>    and was amazed at how much 'pressure' was in the attic.  While I
>    was cutting out the hole in the roof to install it, most of the 
>    sawdust was actually blowing back at me!  They cost around $20 at 
>    Grossmans on sale and are definitely worth it. I had a severe lack 
>    of ventilation in the attic prior to this so I installed this vent 
>    as well as vents under the eaves.  I don't consider myself an expert
>    on this by any means but I wouldn't consider an attic fan (or fan
>    in the attic in your case) unless I wanted it to draw hot air from
>    inside the house.  That is what they are designed for.  
>    
>    -Jim
>
>
	I'd check with your local building inspector on this before going
	ahead.  When I did a reroofing of my place, I wanted to install a
	turbine vent, but the inspector said that they are not acceptable
	in Merrimack, NH, stating reasons similar to those voiced for not
	using an unprotected electric fan...namely in case of fire.
	
	He went on to say that  although  the thermostatically controlled
	ones are approved, he dosen't recommend them  on  account  of the
	possiblity of the thermostat failing in a fire  and  keeping  the
	fan  going.  In summary, I suspect that you  should  do  anything
	that is within your town's code and that you feel safe with.
	
	Chris

	>>     When I did a reroofing of my place, I wanted to install a
	>>turbine vent, but the inspector said that they are not acceptable
	>>in Merrimack, NH, stating reasons similar to those voiced for not
	>>using an unprotected electric fan...namely in case of fire.
	
	  I never would have thought about something like this being
    against code or even asking a bulding inspector about it...especially
    since it is passive.  What DID he allow you to install for ventilation?

    -Jim

	re: .-1
	
	He (Gene  Ledger)  was  adamant  about  ridge  vents.    All  new
	construction  now  requires    ridge/soffit  venting.    Although
	reroofing isn't new construction,  he  STRONGLY suggested using a
	ridge vent on older homes (mine) with only gable vents.
	
	He muttered something about not passing inspection, however, when
	my wife went to get the permit, she got a schedule of permit fees
	and  nowhere  on  it was any mention  of  needing  a  permit  for
	reroofing  or  residing.   How he is supposed  to  'pass/fail'  a
	roofing  or  siding job without knowing about it beats me...  Now
	this was about 4 years ago and things may have changed..
	
	At  any rate, I took his suggestion and am  statisfied  with  the
	results in winter and summer.  Summer results in a  cooler  house
	and  the  winter  results  in an attic space incapable of melting
	ice (no ice dams).
	
	Chris

    
     If you're looking at turbine vents for the roof a couple of quick
    points from my wallet.  Don't save money on the off brands - I finally
    got 'Whisper-Cool' (spelling?) base and turbine when the bargin
    bearings went out after two years. The W-C's were running after
    seven years when I sold the house 2 years ago.  Second, the energy
    savings and comfort level improvement are substantial.  
    
    And about vents and fires:
    
    Any inspector killing an install of wind driven turbine vents should
    be replaced effective last year. Sure there's a lot of emotion over
    the fire issue but any inspector who can't separate fact from fiction
    on this one, should be on the sidelines.  You need venting to save
    the house in normal use. Screened vents, soffit vents, ridge vents,
    turbine vents, open windows even, will provide venting and yes,
    assist in a speedier more destructive fire.  I know of no one I
    respect who advocates doing away with venting.  Powered fans are
    a different issue. Not passive, bad environment, out of sight and
    mind - I'm not concerned so much about their venting assisting a
    fire, as their lack of servicing causing one. Even here, I'll go
    along with power venting in a crunch.  
    
    Stopping folks from utilizing vents of whatever (passive) type by
    hitting on the fire issue is a disservice.  Concerns unduly weighted
    on fire control and venting are misplaced and misdirected.  

oi've been reading all this talk of ventilation with great
interest -- especially in view of the horrid summer we're
suffering thru and the fact that air does not seem to move
AT ALL in my house (sleeping has been horrendous).  i've
discovered that at least part of my problem is insulation in
the soffets.  it's the 'blown in' type and whoever installed
it did so without any knowledge (or concern) for the
apparent importance of soffit vents -- the insulation
completely fills in the soffit space. 

obviously i need to open up the soffit vents and let them
'do their thing'.  my problem is this:  the distance from
the attic floor to the bottom of the soffit is about 5 feet
and it's quite difficult to get in there and pull out the
insulation. 


		^
	       / \
	      /   \
	     /     \
	    / ATTIC \
	   / _______ \
	  /*/       \*\
	 /*/         \*\-----INSULATION
	/*/|         |\*\
	   |	2ND  |
	   |	FLR  |
	   |	     |


any sug's on how to suck or pull this stuff out.  it's like 
molded powder that crumbles when you touch it.

also, would it be a bad idea to take out ALL of the 
insulation that's in the soffit space?   or, should i take
pains to clear a 'tunnel' thru the insulation from each of
the soffit vents?  if so, is getting at the soffits from the
outside the only way to find out just where each vent is
located? 

lots of questions, i know.  but we're dealing with a first 
time homeowner who has a minimum of experience and a 
do-it-yourselfer's pocketbook.

by the way, looking at the soffit bottom from the OUTSIDE of 
the house (which is 100+ yrs old, with 2 yr. old vinyl 
siding), i see that it is perforated vinyl.

any suggestions/comments may help provide a decent night's 
sleep for the first time in weeks.

thanx, y'all.
michael

    Suck it all out with a shop vac.  
    
    Install styrofoam proper-vents.
    
    Re-insulate with unfaced fiberglass mats.

    If you don't want to suck it *all* out, block off a section above
    the ventilation ports at the point where the roof meets the walls,
    and suck out *that* portion of the insulation.  You will still have
    an insulated soffit area and also the venting needed for good air
    circulation.
    
    Pat.

    I ran into a similar problem in my house and you can push in the
    air circulators, a 12" x 48" piece of styrofoam molded to form a
    channel, and then use the vacuum to get rid of the insulation in
    the channel. The air circulators come 24" x 48" and you break them
    in half for 16" o.c. studs, or use them as is for 24" o.c. Most
    lumber yards carry them, they cost around $1.50 a piece. The insulation
    below the air circulators will hold them in place, but toss in a
    few long staples if you can get at one end.
    						Chris

    How about on a double wallplate next to your furnace switch (which
    is normally mounted high on the wall inside or close to you cellar door.
                                               

also, how about a timer.  a 1 to 6 hour one for instance?  it couldn't be 
left on and would be much less likely to be playfully or accidentally 
turned on.  just put it on the first floor somewhere, our's is on the 2nd 
(near the fan) and it's not convenient.

craig

    Our emergency furnace switch was installed -when the house was build 30 odd
    yrs ago- about 6' high, on a centrally located interior wall -facing
    the stairs to the basement. When we installed the "whole house"
    attic fan, I put the switch just about the same place one floor
    above facing the stairs from the 1st to second floor. Works out
    just fine
    
    				herb

    
    
    The whole house fan CONTROL , which is about the same size as a
    ceiling fan control, should be in its own single box up high enough
    so it won't be bumped. Also keep in mind the control will put out
    a certain amount of heat. Ours is in the hallway a little less than
    6' up. I wouldn't put it in with any furnace emergency switch as
    it may be against code. It should come with its own electrical box
    and cover anyway. Ours did. 
    
    Bob

    My father double switched his so that there was one to turn it on/off
    for normal operation and one in the closet that could be switched
    off to completely disable the fan. You are probably wondering why,
    right? Well my nephew found the switch one winter evening and turned
    it on which might have been fine but the fireplace was lit.
    Want to talk about a draft problem? Needless to say it made for
    a few tense moments until we figured out what was happening.
    The second switch was added the next day. Almost a must in my opinion
    if you have a fireplace or stove and there's a chance that the fan
    could be turned on while you have a fire going.
    BTW- both switches are in series ANDed as it were.
    
    -j
    

    The fan control definitely should be in a separate box from the
    furnace control.  BTW I believe the emergency switch is now located
    in the living quarters.  Mine is just inside the cellar door so
    that you don't have to stare at this big red wall switch.  Of course
    if there's a fire caused by the furnace, it will be in the cellar
    and one of the LAST things you want to do is open the cellar door!
    
    It's a lot like these folks buying one of those Ronco (sp?) fire
    extinguishers seen on the tube.  where do they put it?  Above the
    cooking surface of the stove to be nice an handy.  Where's the last
    place you want to reach when there's a stove fire??  [answer left
    as an exercise to the student]
    
    The dual control sounds like a good idea provided it's documented
    for the new owners.

    We're buying a new house and one of the extras is an attic fan.
    We're wondering if we should have the builder put it in or wait
    and do it ourselves.  The specs I have for it are "attic fan, 2
    speeds 755 CFM high 500 CMF low with timer".  He wants $700 for
    this.  I found out from reading this notes file that there's a
    difference between attic fans and whole house fans.  I got the
    impression from the realtor that this is a whole house fan even
    though it says attic fan.  There will be a vent in the ceiling
    of the 2nd floor at the top of the stairs.  Would this be true
    of an attic fan?  How difficult is it to put in a whole house 
    fan (assuming we have adequate attic vents)?  We'd have to cut
    the hole in the ceiling, mount the fan, bring power to it and
    mount the control somewhere.  Is that about right?
    
    Thanks,
    Barb

    In the previous house I had, a whole house fan was there when we
    bought it. It was mounted above the grill in the hall and would
    open the grill louvers when it went on (by air flow). The air was
    blown into the attic where it exited the house via soffit and gable
    vents. This unit was 3' blade tip to tip and was belt driven from
    a large electric motor.
    
    The way I understand it, an attic fan is smaller and therefore won't
    pull as much air through the house, used primarily to vent the attic.
    This may be a question of semantics, so you'd have to speak to the
    builder to be sure.
    
    $700 sounds a bit high, but I havn't done any pricing lately. If
    you could get the builder to frame out the opening and then just
    sheetrock over it to make the inspectors happy (or just install
    the louvered grill) the fan itself is an easy DIY job. If the house
    is being built, the extra electric line can be run ahead of time
    and connected when needed at both ends. Go out and do some pricing
    will give you a better idea of what they cost today. Just make sure
    that you'll have enough attic vents to exhaust the proposed CFM
    that the fan will have.
    
    Eric

    $700 is too high - especially is the house is not complete. A
    handyman would probably charge less with the house *complete*.
    Most whole house fans don't need any extra framing, or even
    a switch (as long as you don't mind a pull switch). A decent
    fan (with louvers) will run you $200 max. The labor would
    total about an hour between mounting the fan, electrical, and
    trim. Tell him to have the electrician put a light where you
    want the fan, and a switch where you want to control it. That
    should be no more than $100. You can then replace the light
    with the fan, and the switch with something to control the fan
    whenever you want.
    Total expense: $300.00
    
    John

If you've got a reasonable builder, you might be able to get him to rough frame
the fan opening.  Then if you've also got a reasonable electrician you might
be able to get him to run some wires OR at least some power to were your would
eventually mount the fan.  I agree that it's NOT a big job even if you had to
do it from scratch, but while framing we're probably not talking more than 15-20
extra minutes worth of labor (if that!).

-mark

    What's there to frame? The fans don't *need* to be framed in. I
    installed a 30" Braun fan (from Somerville), and it just mounts
    on the existing joists. The thing is steady as a rock.
    Power was a little more of a pain. I went off of a closet light
    that was close by. I also added a thermostat and a variable
    switch which took some more time.
    If you ask the builder for anything, make it extra ventilation,
    and power to the spot where the fan will be.
    
    John

    500 CFM  isn't  much.  My  whole  house  fan  is specced at 5 or 6
    thousand  CFM.  Since  I  have  a  fairly large house I bought the
    biggest  model,  but  the  smaller ones still moved more than 3000
    CFM.  It does a wonderful job of cooling the house. The specs call
    for  8  square feet of windows open in the house and 8 square feet
    of  gable or ridge vent in the attic. The fan cost about $200. The
    instructions said to put it on its own 20 amp circuit, which seems
    like  a  little  bit  of overkill, since it's not supposed to draw
    more than 10 or so amps.

    Physical installation  is pretty straight-forward. Cut a 30" x 30"
    hole  in  the  2nd  floor  ceiling, and drop the fan on top of the
    joists.  Install a shroud or two and wire it up. I spent more time
    running a new circuit from the basement than I did on the physical
    installation.

--David

    The cost of the fan is about $200 for a whole house fan.  It is
    worth the money because you wont have to run the a/c for at least
    1 month in the spring or fall.  It will quickly cool a house in
    minutes.  Make sure you clean out the fireplace VERY well before
    turning it on or you will have soot all over the place.  
    
    $700 seems way to high.  I agree with the other replies about having
    the builder put in the electric as that is the biggest headache
    about installing the fan.  My dad put one in his house about 2 months
    ago and the wiring took him a hour or so but the installation of
    the fan took about 30 minutes.
 

I know this has been discussed many times before, but we DO have a new audience.
If the thermostat mentioned in an earlier note was the type that turn the fan
on when the attic gets too hot, please do yourself a favor and throw it away
right now.

The theory sounds great until you stop to think that when there's a fire in
your attic it will also heat up, turning on the fan and whipping up the fire
even more!

-mark

    RE .7
    Couldn't agree more. I forgot to mention the installation included
    a device that *shuts off* the fan at extreme temps. It wasn't any
    work really putting it in since it's up there with the fan.
    
    John

    
    
    I installed whole house fan in my home in Georgia.  A device that
    I believe was called a firestat was required by the building code.
    This device was supposed to cut the power during a fire.  It cost
    about $10 at a local electrical supply and installed with just a
    screwdriver.
    
    al
     

    
    RE: .9
    
    Is this "firestat" the same thing used above a furnace?  Do you
    have to put up more than one to cover the entire attic area?
    
    About the electrical, I would imagine code requires a dedicated
    line to the fan since it is a "fixed" appliance.  I would make it
    20 amp since it can't use more than 80% (16 amp) if it is considered
    a "continuous load".  Check the code in your area but 20 amp should
    cover it.

    
    Ok, this is going to get technical.;-)  The little whosit over my furnace
    here in Mass. has a little wheel on it that is made of a material
    that has a low melting point.  When the wheel melts a spring loaded
    screw will be pulled back into the case and cut the power.  This
    doesn't *look* anything like what I put on the WHF but could work
    internally the same.  The 'firestat', again I'm only marginally
    sure of the name, was a metal box about 2" X 2" X 4" with four
    terminals inside a cover.  The white and black wires were attached
    to the terminal and secured with clamps to the normal romex.  The
    box was then attached to the rafter with screws.  I'm assuming that
    there was some low melting point metal or some bimetal that would
    break the connection in case of a fire.  However, I didn't take
    the box apart to look.  Oh, and there was just one next to the fan.
    I can see where it would be better to have several but the code
    only called for one.
    
    al                  

    The time to have this fan work installed would seem to be now.
    If your building a nice new house the last thing your going to
    need is to have to do more work when you move in. If your not
    going to have the contractor do this work, than i dought that he
    would do any special wireing without a price tag. As one mentioned,
    these typ fans should be on there own 20 amp,12gage line. If you
    tellthe builder that you do not want the fan, he might just bring
    power from an already used up 15 amp line. the main reason for the
    20 amp is for peak turn on wattage, i have a solar blower with the
    same type power surge. If you start adding up all the wire needed
    (12 gage) the breaker, the fan, grill work, special fire devices,
    switches etc. to do this job you might as well have the builder
    do it with a warranty, oh, and dont forget a little something for
    the labor. perhaps the builder will talk about the price, or break
    down the price to show you what your paying for. Im not saying his
    price is right, but i do think it will be more work than is being
    let on to be. You might end up haveing an electrician come in to
    make connections for you in the long run anyway.

    The installation of today's whole house fans has been simplified.  It
    used to be that you had to cut ceiling joists and frame it for the fan. 
    The fans now come with a cowling that installs between the joists so
    that you just mount the fan on top of the ceiling joists.  The only
    thing you have to cut is the drywall in the ceiling and attach the
    louvers from the bottom.  I would have the electrician install the
    wiring and switch and do the rest yourself.  It's not difficult.  Just
    don't wait for a 90 degree day like I did to do the installation.  

    I added on a 1500 sft addition and included a WHF and an attic fan.
    I wired the attic fan with a thermostat for the heat in the summer
    and a humidistat for the moisture in the winter. 
    
    My question is:  What amount of humidity in the attic will allow
    me to maintain proper moisture control? (in other words what should
    I set the humidistat to?)

    Dave

	Aprilaire recommends the following settings...

	Outside
	Temperature		Humidity
	(in Fahrenheit)		Setting
        -----------		----------
	   +90			   70%
	   +80			   65%
	   +70			   60%
	   +60			   55%
	   +50			   50%
	   +40			   45%
	   +30			   40%
	   +20			   35%
	   +10			   30%
	     0			   25%
	   -10			   20%
	   -20			   15%
	   -30			   10%

	You may want to check with your manufacturer to be certain...

    Is it possible to install a WHF in an attic that has blown-in
    insulation ?  Will the insulation get blown all over the attic ?

    The blown-in insulation should have settled. A small amount of it
    may fly away at first, but it will stop soon. The air flow does
    not actually disturb the insulation since it goes from the fan to
    the roof vents...
    
    M
    

    I have blown-in insulation AND an attic fan. I have used the attic
    fan a lot and there has been NO problem with the insulation blowing
    around.
    
    					Kenny

    I want to reopen this topic briefly. I read thru all the FAN notes
    and didn't see any mention of a DELTA wholehouse fan. They are the
    brand now sold by Sommerville lumber (at least in Westboro) They
    no longer carry BRAUN.(sp?).
    
    The specs say:
    30"  760RPM  2speed 1/3hp 4.6a  4800CFM    beltdrive  need 9sq'
    						          of vent. 
    							  in attic
    
    36"  460RPM  2speed 1/3hp 4.6a  6500CFM    beltdrive  need 11sq'
    
    Anyone out there own a DELTA fan or can comment on these specs.
    Price for 30" is under $200 and the 36" is $229. Can get a variable
    speed switch for $24.99 made by DELTA for this fan. They also
    claim that the 30" fan is made to cool a 1700sq' house and the 
    36" fan is made to cool a 2300sq' house. The 30" fits on the joists
    and the 36" I must cut the joists.( Any comments on how easy it
    is to box in joists would be appreciated,it looks easy).
    
    I can also get a FASCO but they were about $100 higher in price.
    The DELTA fans are on sale at Sommerville until July 1.
    
    As far as attic ventilation goes I have 2 gable vents. I have soffit
    vents on both sides of the house (36' each side) and I believe I
    have ridge vents on the main part of the house. I know the attached
    family room has a ridge vent. Can someone tell me what the actually
    ventilation area is for the soffit and ridge vents. The openings
    on the soffits look like little slits.
    
    thanks
    /Jay sweeney

    Rumor has it that the next issue of Consumer Reports will report on
    home cooling, including air conditioners, attic fans, and whole-house
    fans.  It should hit the newstands the last week in June.  You might
    want to try to hold off until then (or arrange to get a rain check from
    Sommerville Lumber, which will give you more time to decide).
    
       Gary

	Something else that you might want to consider is the location of the
fan and how quiet you want it to be.  All other factors aside (ie. type, and
thus noise, of the motor itself), the 36" diameter blades running at 460rpm
will have the tips of the blades moving around 13% slower than the 30" diameter
blades running at 760rpm.  In general, the slower the blades are moving the
quieter the fan will be.  You might want to consider asking the dealer if you
can run both fans at full speed for a noise comparison in the store.

								-c

    .41:
    
    That issue should have been delivered sometime last week -- if you
    don't have a subscription, check your news-stands now!
    
    Dick

    I've been checking the bews stands in the Marlboro/Hudson
    Framingham/ashland and Milford areas, but no luck so far. Most stores
    I've been in have the new magazines in for all other topics except
    consumer reports. If anyone sees the July '89 CR issue out there
    could you let me know where I can get it.
    Thanks
    /Jay

    MRO1 library has it, but you can't take it out.
    
    Elaine

Thanks. I work at HLO and can stop by there this afternoon on my way
    home. For some reason our library doesn't have the JULY '89 issue
    yet. I'll check again this afternoon before leaving.
    
    /Jay

    Well I went over to MRO1 and got the JULY '89 CR issue. It was
    informative as far as what to look for in a whole house fan but
    they didn't do any type of comparison between models. They compared
    AC units only. So it's back to making the big decision. Which model
    to choose? 
    
    I've narrowed it down to 3 fans
    
    FASCO	30"
    DELTA	36"
    TRI ANGLE ENGINEERING	30"
    
    Have to make a few more calls to get the low speed specs on these
    and get a price on the FASCO.
    /Jay

    Is it possible to put in a whole house fan that can be removed?
    The best place for one in my house is right where the opening is
    to get into the attic.  I'll make a new opening if I have to but
    would rather not.  So, can a fan be installed in a way that I can
    just push up and move it aside if I want to get up there? 
    
    Chris D.

    re .48:
    
    Yes - that's how mine is mounted. I built a frame that drops into the
    attic opening, and mounted the fan on the frame. Off-season, I replace
    it with another frame that matches the woodwork in the hallway and is
    heavily insulated.
    
                      |           ||
                      |           ||     fan frame
                      |           |`------------------------ 
                      |           |XXXXX  
                      |           |XXXXX <-- foam
                      |  joist    |-----.
                      |           |     |
                      |           |     |
                      |           |     |
                      |           | 1x2 |
                ------------------|     |
                                  |     |
                    wall board    |     |
                ------------------`-----'
                  |  casing     ,-----'
                  `------------'  
    	

    I finally mad up my mind and bought the FASCO 30" fan 7800CFM ...
    It also has 3 speeds which I find nice. 
    
    The installation was easy but the heat in the attic was unbearable.
    I worked on the installation Sunday night for 2-3 hrs. Figured out
    where it would go and cut the floor joists. The floor joists were
    not exactly 16" OC. so some extra work had to be done to compensate.
    By the time 8:00pm rolled around I had made all the measurements
    and all boards for boxing the joists in were cut and ready but I
    had had it w/ the heat. Soaked and 2 lbs lighter slithered out of
    there. Monday the electrician came and installed a seperate circuit
    breaker and we ran a wire up from the basement to the attic. I let
    him wire up the whole thing since I wanted it completed that night
    and it only took him 1/2 hr to wire up the fan itself after getting
    the wire up to the attic. I spent the most of Monday afternoon in
    my attic. 1pm-5pm. I cut out the opening and boxed it in. The fan
    is running great and cooled the house right down on Monday and Tuesday
    night. Well I lost another 4lbs Monday and was sick all night mosty
    likely due to the heat.
    
    One suggestion, if you install the fan this time of year , wait
    for cooler weather and work in the mornings rather than the afternoons
    Also put a fan in the attic to blow some of the air around while
    you are working. I wanted the fan installed ASAP so I didn't want
    to wait another week. I figured I'm in shape and could handle the
    heat. It has nothing to do w/ being in shape. Your body is trying
    to cool itself constantly and the attic temp must have been above
    110 F. I was at least smart enough to drink lots of water every
    1/2 hr to hr. to keep from dehydrating. I also knew as long as I
    was still sweating that my cooling system was still at work.
    
    Anyways I the fan is great . Thnaks for all the help
    /Jay

    
    Give Fan Distributors in Cambridge a call. Ask for Dana and 
    tell him your from DEC. He'll tell you how to calculate the 
    size fan you need, and he'll probabley have it in stock, for
    you to pick up, or he'll ship it out to you. 
    
    868-1310
    
    steve

    re. 49
    
    Nice Graphics.

    
    	We're now planning on installing a whole-house fan in a stairway
    that leads up to the attic.  (Of course, the stairway hasn't yet been
    built -- this is turning into a merging of the "fan" and "better access
    to the attic" projects...)  My question is: How do I keep unpleasant
    flying critters (such as hornets) from coming down from the attic?  I
    don't have any nests in the attic, and the vents are screened, but
    there are some dead hornets laying about which means the potentials of
    live hornets paying us a visit instead of staying up there to die.
    
    	Putting a screen in the fan opening looks like a solution that is
    too obvious to be right.  How much will doing this block the airflow?
    Has anyone else screened in the opening?  Thanks!
    
    							-craig
    
    p.s.  Obviousely my first step will be to check out all the vents'
    screens and tighten down any openings.  It will be a very difficult
    job, however, so I'm not acting on the certainty of eliminating all the
    access paths.

    The fan frame I mentioned in .49 is covered with insect screening. It
    must cut down a little on the efficiency, but it still moves a whole
    lot of air. Other than having to vacuum it once every two weeks
    or so during heavy usage (when you can't see the fan through the
    screen, it's time to clean), I've had no problems - and no bugs.
    
    The other reason I like the screen approach over the flow-operated
    louvers, is that you get some natural venting even when the fan is off.

    
    	Thanks for the input!  Its nice to know that I won't be spending
    all that time building it just to have the screen cut the efficiency
    down to near worthless.
    
    	Incidently, what I'm planning on doing for the time being is mounting
    the fan/screen inside of the "summer" door so that accessing the attic is
    just a matter of turning off the fan and opening the door.  (Hmmm, sounds
    like a good place for a pressure switch to cut the power to the fan as
    soon as the door is opened...)  For the winter, we'll have a "winter" door
    that is heavily insulated.  At each change in major season, all we'll
    have to do is pop off the current door and put on the other one and
    we're all set!  (If this doesn't work out well, or if we have to
    convert the den into another bedroom, I'll install a regular ceiling
    fan in the hallway.)
    
    	Comments?
    
    							-craig
                        

    I am curious about just how hot an attic should be allowed to get.
    
    I have a "hip roof" colonial, so originally the roof only had soffit
    vents.  The last owner installed a thermostat controlled fan in the
    roof and had the "on" temperature at 100 degrees.  The minimum setting
    on the unit is 90 degrees and the maximum is 120 degrees.  What I have
    found is that even at the highest setting, on a typical day, the fan
    goes on at 10:00AM and goes off at about 5:00PM.  My concern is the
    strain on the motor and on the electric bill.  I shut the fan off the
    other day and watched the temperature and it went up to about 178
    degrees on an oven thermometer.
    
    The house is well insulated with 6" of blown in fiberglass on the floor
    of the attic, should the "ceiling" of the attic also be insulated?
    There is a second vent that was installed with the alarm horn in front 
    of it, but it doesn't block the entire openning.  I should also mention
    that the attic is also used to store those things that we expect to
    use again some day, but never will.
    
    Charlie
    

    re:50
    
       The attic floor insulation is to keep the living space air , in the
       living space. Insulating the underside of the roof accomplishes
       nothing , as the heat is already lost (from living space) once it is 
       in the attic.
      What you need to do is better vent your attic to exhaust the buildup
      of heat from outside. This can be accomplished with end type vents.
       Or with a ridge vent, or roof vent.
      I lost an end type vent when I added an addition to the side of my
    home. The attic got way to hot. So I added a roof vent. It is an
    aluminum type w/ a rotating top. I bought it at Grossmans and it
    has a lifetime gaurentee ( if the top is not spinning, its broke !)
    The benifit of this type is that it is convection drivin. The heat
    exiting the vent stack causes the top to spin and pull the heat out.
    (No electric consumption) There are vent size calculations for attics,
    it takes into account cubic footage etc. .
    
    
                                      good luck/bob
    

    My Sears whole house fan (3 years old) has croaked. Sometimes, though, if 
    I turn it on and off (say 100 times) it will kick in and start and run 
    fine. (I have the "dimmer" type of control which puts the fan on high
    as you turn it on, then you keep turning it to reduce the speed).
    
    I believe there is a firestat in the circuit too. 
    
    Has anyone else had this problem? I don't have any electrical test
    equipment to check the thing out (not that I would know what to do in
    the first place...)
    
    thanx..

    It its wired like the one I had in my previous house, there are a set
    of contacts within the motor for starting. Once its up to a specific
    speed, a centrifugal switch transfers the current to the "run" winds.
    Does your fan have a belt driven fan or is the motor on the same shaft
    as the fan?
    
    Eric

    re:.58
    
    The fan is on the same shaft. There are no belts.
    
    Thanx....
    
    Jack
    

    I would try taking the "dimmer type switch" out of the circuit,
    just disconnect the power, remove the switch plate and switch
    from the box, disconnect the switch and tie the switch leads 
    together with a wirenut. Have someone apply the power and see 
    if the problem is solved. 
    If you have multiple windings your fan will usually be a 2 
    speed or 3 speed type and you will have to check out each winding 
    individually. You may be lucky and have a defective switch.
    
    								Chris

    Funny how things get dragged out.  When this note started I was
    going to put in a new fan. Now, after finishing the new roof and
    multiple other projects I'm finally ready to do it.  
    
	I've got a couple of questions.  Anyone know of any advantages of
    belt driven fans over direct drive fans?  Sears 30" belt driven fan is 
    about $60 more than the direct drive.  Is it worth the extra price?  
    
    	Also, the fans are made by Patton.  Anyone familiar with them?  
    
    	Some people have added dimmer switches to 2 speed fans.  Does this 
    have any detrimental effect on the fan motor?
    
    Thanks,
    
    George  

George,

Mounting the motor off center allows for noise isolation, gear
reduction so that the fan would turn slower for the higher (but
more efficient running) of the motor. Usually, industrial fans
are belt driven.

cal hoe

Patton is a well-known maker of fans, and I've been happy with the Patton
fans I've owned.

The whole-house fan I installed years ago was a Sears direct-drive, and
I was happy with it.  It varied its speed according to the attic temperature.

				Steve

    I am waiting for my Sears (a Patton) whole house fan to come in.
    I also ordered the thermostat and a firestat for it.  Sears wants
    about $45 for the thermostat.  That sounds like a lot of money to
    me but then again I haven't bought a thermostat before.  Rather
    than buy the Sears thermostat can I get a less expensive thermostat
    at a heating supply dealer that can be used with the fan or is there
    something special about a fan thermostat?
       
    Goerge
   

    Thermostats for the whole-house fans typically control the 120 volt
    AC line directly.  You CANNOT use (most) thermostats designed for
    home heating use since they (most) are low voltage/low current units.
    A thermostat for electric baseboard heating is probably not going
    to work well as it doesn't have the higher temperature range that
    the whole-house fan unit would.

    
    -.2
    
    	That's funny, I just installed a 24" Air Master in the attic
    opening and all I have are the two standard gable openings and
    everything appears to vent fine. I also have *NO* soffit or ridge
    vent openings either. In .2 something was mentioned about the air
    being forced into the electrical outlets?? Seems to me that this kind
    of thing would be difficult to do today. The only opening from the attic 
    to any electrical outlet is a whole big enough to pass the wire(s) through.
	In any case...if things continue to run as they are right now, I'll
    	assume I have enough venting in the attic. BTW, I thought the
    concept of a 'Whole House Fan' was exactly that, to cool the entire
    house, attic and all! I open the slider in the basement and the fan 
    it draws the cool air upstairs into the living area quite well.
    
    John

I just tried the whole-house fan in my "new" (24-year-old) house, which 
definitely has insufficient venting.  There is quite a draft out of switch
boxes and outlets when it is running!  On the to-do list this year is
a re-roofing which will include ridge and soffit vents.

				Steve

    re: .60
    
    
    Thanx for the tip (5-Feb!) on bypassing the dimmer switch. The fan worked ok
    with the switch bypassed. I bought a new dimmer switch ($40 at Sears,
    talk about a ripoff!) and the fan is back 'on-line'.
    
    Thanx again
    
    Jack

	After searching through the Yellow Pages and spending too much
time on the phone I turn to Home_Work.  I need to have the fan section of
our whole house fan repaired.  Any suggestions in teh greater Maynard
area (Boston to Worcester)?

	The fan section consists of the blades and a collar.  The blades,
connected to each other at a common collar, fit over a collar which sits
on the motor shaft.  The blade collar must be pressed on to the collar.  The
collar is held onto the shaft with a set screw.  My efforts to put this
mess together has always resulted in an unbalanced fan which resulted in
the blade section flying off.

	Any assiatance will be greatly appreciated.

Doug Williams

{sorry if this is covered in another note - I checked the dir and nothing 
seemed to match - please move if needed}

We have a dilemma that nobody else seems to recognize (or admit to), and I'd 
like to know if I'm worrying too much.

We are having a new house built, and one of the features being added is a 
whole house fan; so far so good.  Our dilemma is that the hot water system 
is a tankless in-furnace unit, which means that to make hot water the 
furnace comes on.  Why is that a problem?  Well, the whole house fan will 
very effectively suck all those furnace gases back down the chimbley and 
into our house.  The obvious answer is to spend money and have a gas 
or electric water heater hooked up for use during the fan seasons, but that 
is expensive.

Does anyone have both a whole house fan and a furnace fired hot water 
system?  If so, can you detect any gases when both are running?  Is there 
something that can be done to keep the gases from being sucked in?

It won't be practical, or effective, to keep the basement door shut and a 
window open, so that's out.  Any other (inexpensive) ideas?

Thanks,

/greg

ps - we are already having the furnace thermostats wired so that the heat 
cannot come on when the fan is running.  This is an important safety tip 
that anyone with a furnace and fan should do.  It is very easy for the fan 
to bring the house temp down below the thermostat settings, especially in 
the spring or fall when you get warm days and chilly nights.
    

    You can directly supply air to the furnace through a seperate intake
    directly from outdoors. In fact I've heard it is more efficient to do
    so even in winter.
    
    We have not had your setup but did have a attic fan. Where do you plan
    to suck the air from, the cellar or the main floor. We never bothered
    to get the air from the cellar because it was musty. The main thing the
    the attic fan does is remove the heat from the attic and living space.
    You don't really need to suck the air from the cellar and possible
    cause the problem you describe. I also think if you supply enough air
    input the presure of the furnace blower and heat will generate enough
    to overpower the draw from attic fan.
    
    Why would a standalone hot water heater be any better (it still has to
    be vented)? In fact the setup of gas furnace and seperate gas hot water
    (no attic fan) we have today would be even worse. Because the furnace
    has a closed system exahaust to the chimney. And the hot water heater
    has an intentional gap between the heater and vent pipe in which fumes
    could easily be sucked from.
    
    We did have a problem with a dryer vent next to a window that supplied
    air into the house and we had to keep it shut when the fan was on.
    

    I don't understand how the fan will draw what's exiting the chimmney
    into the house.
    A WHF draws air into the attic, from whatever source is available.
    If you have one window open in the house, and turn on the fan, the
    air will be drawn from the outside, thru that window, and create
    the air flow into the attic and out the vents.
    Now if your house is shut tight, and turn on the fan, you might
    get something like what you've described. Just don't turn on the
    fan unless you have something open to the outside.
    Btw, we have a WHF and a tankless WH. I've never noticed anything like
    what you've described.
    
    John

    I agree with John in .2 - my first house had a oil boiler with
    tankless hot-water and I installed a whole-house fan.  Worked
    fine.  But you're never supposed to run the fan unless you've
    got sufficient air coming in through open windows, etc.  If
    the flue gases are being pulled in by the fan, either open more
    windows or get the boiler /chimney repaired, as that shouldn't
    happen.
    
    		Steve

    I had the same setup in a prev house, and even with the downstair
    windows open, I would occasionally generate a reverse draft by the
    furnace. Just leaving a basement window open near the furnace seemed to
    cure it when the fan was on.
    
    Eric

    re - all
    
    I should have been clearer I guess.  For various reasons we will not be
    able to "seal" off the basement while the fan is running, and by
    definition, even with windows open, the fan creates a negative pressure
    in the house and air will flow in from all available points
    proportionaly to its resistance.  I can leave basement windows open,
    but need to know at what point a downdraft will occur in the chimney.
    
    The idea of a fresh air source is a good one; I'll look into whether or
    not it can be installed on this furnace.
    
    In any event, all theory aside, we have a WHF in our current house, and
    I can still feel the sweat on my palms from the time we were awakened
    in the middle of the night to the sound of every smoke alarm in the
    house blaring.  What happened was that it was a warm fall day and we
    were using the fan and left it on when we went to sleep.  Well, fall
    being what it is here, the outside temp nosedived after midnight and
    the fan very efficiently brought the inside temp below what our
    thermostat was set at (somewhere between 55 - 58) and the heat came on. 
    Even with lots of windows open on two floors, and the fan not running
    all that fast, there was enough smoke and CO in the house to stink the
    place to high h*&&.  It is interesting to note that the blocked-chimney
    sensor in the furnace did not shut it off because the reverse air flow
    did not allow it to recognize the problem.  Now granted, the draft may
    not have been the strongest in that flue, but it is not something I
    want to lose sleep over for the next twenty years. 
    
    Thanks, 
    
    /greg

    
>    The idea of a fresh air source is a good one; I'll look into whether or
>    not it can be installed on this furnace.
    
    This can be done to just about any furnace -- just enclose it in a
    more-or-less airtight closet (with appropriate cleareances) and supply
    sufficient venting to it from the outside (specified in furnace
    literature).
    

    The mention of a thermostat reminded me...
    I put one in our set-up so the fan could be triggered by temperature,
    and be able to leave it on without it running if the house got too
    cold. That would solve your Fall night scenario.
    This however wouldn't solve the issue where the furnace kicks in
    for hot water. The outside source sounds like the best idea.
    
    John

    
    It might even be code. But I think it's a good idea anyway. To put a
    timer on the fan.
    

    Why would it be required to have a timer on a fan (and not other
    appliances (ac's etc))? The heat sensing shut off would be a
    better code requirement. If the fan gets too hot, regardless of
    how long it's been on, it'll shut off.
    
    John

    
    Lets say someone left it on upstairs and shut the windows down stairs
    and left the house. The whole house fan needs the right conditions to
    operate safely. Having a timer would prevent it from running in a bad
    condition indefinetly. But I beleive the heat sensor (not a thermostat)
    is code. For practical reasons it's great to put the timer on for an
    hour and then go to bed. You really don't need it running all night.
    Once the sun is down and the hot air is out of the attic and house it's
    done most of the work.
    

    RE - note about a timer
    
    We addressed this one through the use of a thermostatic cut off.  When
    the temp falls below a certain point, the fan shuts itself off.  This
    is a standard fan option, and is a no-brainer to install.
    
    We have decided that the extra hot water tank isn't necessary after all
    (esp with a 1k estimate) and we will either be venting the furnace to
    the outside directly, setting up a circuit to turn off the fan when the
    furnace is running, or both.  That should do the trick.
    
    Thanks for the ideas,
    
    /greg

    You could use a 3 wire (heat/cool) low voltage thermostat. You would
    have to put in a relay (for low to high voltage) which is easy to do.
    You could still have a timer in series also. Having both (Timer and
    Thermo) would be Ideal. Sooner or later AC or Heat will eventually
    satisfy a thermostat. But an attic fan may never satify the setting and
    run the whole night. But if you shut it off (after a certain point) it
    won't get any hotter (you've already got everything out of the fan it
    can give). Therefore your wasting electricity. Remember even though
    traditionally AC cost more than a fan to run, that fan has about a 1/3
    horse motor on it and is not cheap to run.

    the hi-temp switch is to make sure the fan shuts off if there is a
    house fire! You wouldn't want ther fan to go on because the house is
    hot, because its blazing away, would you????
    
    Eric

    That's a good point :-) Ooooh there's a fire lets turn on the FAN and
    really get it going :-).

    
    
    Why do you just make the fan run slower????

    Steve,
    
    I'm in a similar situation where I'm planning to install a whole house
    fan at some point during the next few weeks. In the meantime, what I've
    been using is a 18" high velocity fan (either Patton or Holmes, don't
    recall) to exhaust warm air from the house at night while drawing
    cooler night air into the house in whichever rooms we've left windows
    open. It's portable, and needs a flat surface to rest on. In previous
    years, I'd set it up on the floor of the dining room and have it
    pointed thru the open slider. However, due to security concerns I now
    rest it on a small table set in front of an open window at the high end
    of the house. The 18" fan does a great job of cooling down 2 bedrooms
    (4 windows total, each open approx 8-12"); it'll do a so-so job of
    cooling off three rooms (6 windows), and seems totally useless on any
    larger area.  
    
    In my situation, I've had the fan for a few years, long before I
    considered installing a WHF, so it's a good temporary fix with no
    incremental cost. Expect to spend at least $50 for such a portable fan, 
    or even more if you want one with higher capacity or more bells &
    whistles. A whole house fan will set you back anywhere from $120-$200
    depending on size/type/model, so the $50+ incremental cost associated 
    with buying the 'temporary' fan may become a factor.
    
    How long before you expect to install the WHF? If it's a matter of
    weeks, you may want to wait. Then again, if we get a hot/humid spell
    in the meantime, the incremental $50 might seem like a bargain...:^)
    
    Good luck with your decision.
    
    Freddie

    What your going to miss with a w

    Re: -.1
    
    I agree with the concept, but my execution is a little different than
    yours. I set up the fan at the 'non-bedroom' end of the house and have
    it blowing out. I close all windows except those in the two bedrooms 
    we wish to cool off. The cool night air is drawn in thru these bedroom
    windows to replace the warm air being blown out at the other end of the
    house. The advantage I gain is twofold: I can cool down two rooms using
    only one fan; and the fan noise doesn't bother us as much as if it was
    in our room.
    
    Re: WHF in general
    
    Remember, too, that the WHF not only will draw in cool night air, but
    will also, in combination with proper venting, force the hot air out 
    of the attic. This action will also help make the house feel cooler. 
    Temps in a poorly ventic attic can reach 150 or so, which is sort of
    like having an electric blanket draped over the house. An attic that 
    is well-vented won't get as hot, and will make it easier to dissipate
    the heat that builds up in the house. In combination with a WHF, it
    becomes even easier to keep things cool.
    
    Again, good luck with your project. 
    
    Freddie

    re: last 2... thank guys
    
    We bought one of those Holmes dual 8" fans from Caldor on slae for
    40.00.  Either fan can be switched for intake or exhaust independently.
    Well the thing works good, but isn't going to cool the house down at
    night.  Just not strong enough, but a nice fan anyway.  Caldor also had
    a free standing fan from hell that moved over (I think) 25,000 cfm.
    I bet it's noisy though!  We didn't get that one.  I'm going to try to
    pick up a ridge vent this weekend and judge if we even need a WHF after
    it's been installed for a few weeks.  I noticed that the house stayed
    fairly cool for quite a while this morning and probably would have
    stayed even cooler had I not opened up the windows and let the outside
    hot air in.  Now I know better.
    
    Steve

re .73:

25,000 cfm?  Are you sure it's not 2500?

    Nope.  The box said 25,000.  In fact they are on sale this week for
    about $50 at Caldor.
    
    Steve

    Maybe it's CFH? (Cubic feet per hour - looks impressive 'til
    you divide by 60!)
    
    	Dick

A 25,000 CFM fan in a 3000 sq.ft. house with 8 foot ceilings could do an air
exchange every minute.

If you push 25000 CFM through a 24 inch square fan, the exhaust air speed 
should be 71 mph.  A stiff breeze none the less.

    Good enough to put parts of your roof, into a low orbit...
    
    q
    

    
    Some good tips here, as far as cut-off, thermostat control, and gabel
    venting. I NEED to install attic venting. I would like a draw thru the
    attic system, taking air from the cool side of the house and expelling
    it out the hot side. Studs are 24" on center, which pretty much limits
    my fan size unless I cut and reframe (TIME?). Attic is 1600 sq ft. 58' x
    26'. 
    
    Any idea on fan RPM's or blade angle for max. CFM? Would I be better
    of with a roof fan drawing thru both gabel vents? 
    Any further experience and info much appreciated!!!
    
    Dave' 
    
                                                       

    WE put in an attic fan last year and haven't had to use the a/c yet
    this year although, that might not mean much since it hasn't been hot
    enough to use it.  
    
    My question is how do I stop the rattle of the shutters?  The fan is 
    quiet, it's the shutters that keep us awake at night!
    
    Thanks in advance
    Ferne
    

>    My question is how do I stop the rattle of the shutters?  The fan is 
>    quiet, it's the shutters that keep us awake at night!
    
	    You might be able to get away with running the fan on high
	for about an hour (or so) and then turning it off when you go to 
	bed.  The house should be cool enough for you to sleep comfort-
	ably by then.  It works for us.
	    You can run it again in the morning and then turn it off
	before you go to work.

					Tim 

    
    Our Nashua split has Central Airconditioning which is quiet pleasant
    on the hottest of days. On merely 'warm' days we try using it in 'fan'
    only position but that just stirs the air a little. 
    It would seem better to suck the warm air out of the house.
    
    Well, we have the vents, the ducts and a fan in the attick 
    all in place... for the airconditioning.
    If I could just switch the outlets to suck and redirect the fan
    air outlet into the attic (or outside?)... would it work? 
    would it be worth it? It would require several serious sized
    air valves. An idea worth pursueing or plain crazy? Should we 
    simply go for a standard whole house fan?
    
    Thanks,
    
    	Hein.
    
    

>             -< Could central air be used as whole house fan? >-

	    It sounds like a complicated and expensive route to go.  A
	24" W.H.Fan runs around $130.00 and is fairly easy to install.
	That would be big enough for a small to medium size split level
	ranch.  Either way, you need plenty of ventilation to exhaust
	the air you blow into the attic (I need more ventilation).
	    Another option might be to install an intake vent in the
	cellar ductwork.  You could draw the cool cellar air and distri-
	bute that throughout your house.  A couple of paddle (ceiling) 
	fans to create some wind chill would make the air feel even cooler.

					Tim
    

    RE; .58
    
    I second .29's suggestion to go with a seperate whole house fan, rather
    than piggy-backing off the A/C system. However, rather than the 24" fan, 
    spend the extra $20-$40 and get the 30" model. Installation is just as
    easy (or complicated, depending on your point of view) as the 24", but
    you'll have a tremendous increase in capacity, and will be able to cool
    off more rooms at the same time. 
    
    We've got a 42 x 26 split, and use a 30" Delta belt-drive (2 speed).
    Even on the hottest nights, we wind up needing our blankets...

> concerning the dehumidifier in the basement.  Will I be helping things by 
> bringing in warmer outside air or causing problems by bringing in outside 
> air that is full of moisture just waiting to cool off and make my basement 
> more damp?

	    I leave my cellar windows open most of the time to keep the
	moisture and damp, musty smell down.  It's a lot cheaper than
	running a dehumidifier, although, probably not as effective.
	Besides, I don't own a dehumidifier.
	    Since you have one, your cellar should have plenty of cool
	dry air.  If you leave the house buttoned up and circulate this
	cool dry air throughout, I would imagine you'll keep the house
	comfortably cool but less expensively than running A/C.  You'll
	just have to drain the dehumidifier more often.

					Tim

>	    Since you have one, your cellar should have plenty of cool
>	dry air.  If you leave the house buttoned up and circulate this
>	cool dry air throughout, I would imagine you'll keep the house
>	comfortably cool but less expensively than running A/C.  You'll
>	just have to drain the dehumidifier more often.

I'm not sure if I follow this, but... A dehumidifier is basically the
same as an air conditioner.  If (and I emphasize "if) you run the
dehumidifier as much as you'd run the A/C, you're not saving anything.

>	    Since you have one, your cellar should have plenty of cool
>	dry air.  If you leave the house buttoned up and circulate this
>	cool dry air throughout, I would imagine you'll keep the house
>	comfortably cool but less expensively than running A/C.  You'll
>	just have to drain the dehumidifier more often.

>I'm not sure if I follow this, but... A dehumidifier is basically the
>same as an air conditioner.  If (and I emphasize "if) you run the
>dehumidifier as much as you'd run the A/C, you're not saving anything.

	    I was going under the assumption that the dehumidifier was
	going to be run, either way.  I know, one shouldn't assume.
	Does a dehumidifier cost as much to operate as A/C?  

					Tim

Actually, a dehumidifier could end up costing more, since there isn't any
requirement to put energy usage labels on dehumidifiers and there's less
inclination to build in energy-efficient features.  But dehumidifiers also
tend to be "small", so consume less power than even a small room air
conditioner would.  Really, a dehumidifier is just an air conditioner which
blows the cooled air past the condensor coils to rewarm it before returning
it to the room.

					Steve

The dehumidifier you have may not be able to handle the extra moisture.  Each
one has a different "capacity", which is the number of pints of water it can
extract from the air in a 24 hour period.  Note that this is different from the
size of the bucket.  So say yours is rated for 18 pints.  If you put it on MAX,
it will run 24 hours a day, and if there is enough moisture, it will remove
18 pints.  If you need to remove 20 pints a day to keep the R.H. at 55% in
the basement, you won't be able to do it.

Also, I don't think the buckets of dehumidifiers hold as much as their rating.
So if you ran in 24 hours a day, you'd have to empty it more than once a day,
or rig up a drain hose.

Elaine

I'm just looking to take the bite off the summer temperature in the house for the
wife and kids.  Our humidifier drains into the washing machine (when we aren't
doing clothes), and easily keeps up with its current load.  I'll try circulating
the basement air as soon as I get my wood furnace blower motor checked out.

								-- Chuck Newman

Time to revive this topic...

	After the recent heatwave, which I was absolutely melting in, I
	started thinking about a whole house fan.  My father is a building
	contractor so he knows a little about them and he suggested just
	putting in fans in the attic windows.  

	I'm not convinced that this would be sufficient.  How much cooler
	would this make the house when one arrives home from work?  We
	keep the house closed up during the day so would it allow the
	house to remain cooler during the heatwave than outside?  Usually,
	our closed up house is cooler, at least downstairs, but during
	the heatwave, the whole house got hot!

	And, if we do decide to go for the whole house fan, after investing
	in attic fans, have we wasted the money spent on attic fans?

	Additionally, the attic is accessible from a pull down ladder
	in the hallway.  I guess the fan could go there and an earlier
	reply to this note drew a diagram showing how to do that but
	I couldn't figure it out.  Anybody tried doing that for their
	home?

	Finally, about how much in todays dollars would such a project
	cost, assuming we can do most of the work ourselves, except the
	electrical?

	Karen

    We have both a gable fan(attic fan-just for attic air movement) and a 
    house fan(exhausted into the attic).  The gable fan definitely makes a 
    big difference during the day.  The house fan should really only be run
    when the temp outside is cooler than the inside(ie/ pull cool air in
    and out through the attic).  The gable fan keeps the attic from
    becoming a heat sink.
    
    Good luck.
    
    -John

    I agree with the last reply.  I put a whole house fan in about 3 years
    ago.  If we ran it during the day it would actually make the house
    hotter by pullng in the warmer outside air.  But I can live with heat
    during the day.  It's in the evening that the fan really makes a 
    difference. On those hot muggy, nights we usually need to get up and turn 
    the fan off at some point (it has a thermostat on it but it doesn't seem 
    to work correctly and I haven't bothered to check it out yet.).  It really 
    cools things down.  I consider it one of the best improvements I've made.  
    
    George

    
    re: last two
    
    What are the wiring requirements for these?  At a pinch, could they be
    wired in to the existing 15 amp lighting circuit (feeds 1 bathroom
    overhead light and two bathroom vanities).
    
    Colin
    

    re: .83
    
    I just put one in; the motor draws 4.5 amps or something like that,
    so it should be okay to hook it into a lighting circuit.  (Of course,
    if you get a BIG (!) fan that has a 1hp motor or something, that would
    be a different story, but I expect most anything you get will be in
    the 4-5 amp range.)

    
      Yes, the attic gable fan is readily available at most home centers
    around NE and sells for about $35. It comes with a setable automatic
    thermostat and fire cutout switch. They are easy to mount and can be 
    used on any normal 15 amp circuit as long as you don't have too much 
    else on it. My guess is that they draw about 1.5 amps max. They make 
    a BIG difference in attic temps which really helps the upstairs.
    
    				Kenny

    re .84
    
      Steve, are you talking about a whole house fan or one of the small
    (Maybe 1 foot diameter) gable fans?
    
      (My reply in .85 is regarding an attic gable fan)
    
    				Kenny

    
    A neighbor installed a big one in the 2nd floor ceiling at the top
    of the stairs from the living rm. and added gravity dampers in the
    attic wall. When the fan started the dampers opened.  We knew when
    he started it for the TV volume would increase.  His was very noisy
    and the placement didn't help.  Suggest if you go with a big one,
    put it in the outside wall in the attic, be sure it has good resilient
    mounts also see about having about a 3 or 4 foot section of ductwork
    attached to the inlet and line it with egg crate type foam. That'll
    stop any noise comming back in.
    
    Have it on a thermostat. Nothing worse than getting up in the morning
    and finding out the conditions changed outside to FOGGY and the whole
    interior of your house is damp.
    
    If you know an HVAC tech or mechanical engineer, ask him/her to explain
    "ENTHALPY" to you, and mention what your doing.  It'll be a BIG help.
    
    Those fans bring in everything; pollen, neighbors cooking odors,
    lets you know when "pepe le-pew" is around, and anything else thats
    airborne.  Screens catch'ell too..   
    
    They do work good up to a point.
    
    Fred
    

    
    Thanks - I'mn thinking about a gable fan, so it should be a small
    motor.
    
    Colin
    
    (If I can't find a gable fan, would a betty davis fan do?)
    
    

Re: gable fan...

    Are these supposed to go in the attic window or are you supposed to
cut a hole in the outside wall for them.  We don't have a louvered vent
in the peak of our roof.  Would a window suffice? 

How do you keep them dry in the rain (if it blows in)?

Karen

    Re: .86
    I'm talking about a whole-house fan in .84.
    

    
      If you mount a gable fan inside on the gable vent, rain isn't a
    problem. If you have it in a window, it defintely can be a problem. If
    the fan is on, it will keep the rain out by the air blowing out, but
    the %90 of the year when it is off will be a different story. The fan
    will likely only last a few years like that. Also, if you mounted it in
    a window, you will likely have to make up some sort of plywood with the
    right size hole in it that will fit in the window opening.
    
    				Kenny

    In regard to adding to the existing bathroom circuit, realize that when
    the non-follically challenged of your household turn on the hair
    blowers and dryers you'll likely trip the breaker.  How about one of
    the bedroom circuits?
    
    Carl

    
    -1
    
    There are only lights on the circuit that I'm planning to use.
    The outlets are on a separate GFI-protected circuit.
    
    Looking at the circuit last night, would it be terribly sinful
    to wire the fan INTO a light box so that the fan could be isolated
    by an existing switch in the bedroom?  The light box is one that is in
    a closet, and I could replace the existing lampholder with one
    that has a pull-cord.  That way I can control the fan & the light
    independently (except that the fan would have to be "on" to get the
    light - no big deal.)
    
    This would give me a really simple wiring solution.
    
    Colin
    
    

having installed both (in separate instances) i have to comment on the choice 
between attic fans versus whole house fans.

attic fans (1 foot or so diameter) are for power venting the attic.  this is 
in case your attic is getting so hot that you are worried about your roof 
shingles melting off.  the only benefit to the living space is reducing the 
slight amount of added radiation heating from a hot ceiling on an already hot 
day.

whole house fans (big 24 to 36 inch) are for moving 2000 to 7000 cubic feet 
of air per minute through your house for cooling.  they work great as soon as 
the outside temperature starts dropping in the evening.  they work ok even on 
hot days by providing a breeze when you've given up trying to stay cool by
keeping the house closed up. 

the two are not very similar at all.  there are situations that require attic 
fans and different situations that require whole house fans; in my opinion 
there are no situations that present you a choice between the two.

regards,
-craig

>    That way I can control the fan & the light
>    independently (except that the fan would have to be "on" to get the
>    light - no big deal.)

	Well, depending on your point of view it may not be "terribly"
	sinful to wire something this way, but just imagine what you'd be
	thinking if you bought a house and found things wired like that.
	You'd probably think, "whoever did this was a real hack - couldn't
	they put in the effort to do it right?"

	Depending on how the light is wired, you might be able to isolate
	the light from the switch, and leave it controlled by just a
	pull-cord. If not, then I personally wold just put in the separate
	switch for the fan. I find that I rarely regret doing things the
	right way (thought I often regret not getting around to doing
	something until I have the time to do it the right way!).

	Roy

    
    Good point, but the hack would allow me to deinstall the
    fan in a few minutes, thus removing the evidence of sloth.
    
    Oh well, I need a light and an outlet in the attic anyway,
    might as well do it right.  Next year.
                                         
    Colin

    Just to add to some comments a few back re whole-house fans....
    
    I've had one for about 10 or 15 years now and consider it one of the
    best investments I've made.  It's installed in a gable end of the
    attic, is about 36" in diameter and came with a timer and variable
    speed.  Since the fan and motor are @15 feet from the hall ceiling vent
    there's virtually no noise transmitted to the living quarters. 
    
    I did see one installed with the fan and motor attached to the hall
    ceiling vent and it was extremely noisy.  I wouldn't recommend this.
    
    Also as mentioned earlier and as common sense would imply, the best way
    to use this on a hot day is to draw cool air into the house using the
    fan at about 6 am; shut all windows and pull drapes reasonably closed
    to keep out hot air and hot sun; when the temp inside exceeds the temp
    outside, open windows, etc. and turn the fan on to bring the cool air
    inside.  In my opinion, this technique is far cheaper and more
    comfortable than using air conditioning.
    
    The drawback is that this doesn't dehumidify the air at all and pulling
    in really humid air does little to cool you off...but it does create a
    breeze.
    
    You also have to be careful to not leave the boiler room door open when
    operating the fan, else the exhaust draft is pulled into the house.
    
    Jim
    

    		       --Wiring a Whole House Fan--
    
    On Saturday, a friend and I put in a whole house fan, not too bad, but
    extremely hot.
    
    However, when I went to wire the thing, I found that I am not as
    familiar as I thought I was.  I need some help wiring if
    anyone can.  Here is the situation:
    
    1.  I have three strand ROMEX, Hot, Common, and Ground, but here is the
    wiring diagram:
                        2 Speed 
                        Switch      HIGH      |-----------
                       ---------   (Black)    |          |
                      |1     2 |--------------|          |
                      |        |    LOW       |  MOTOR   |
                      |        |   (Red)      |          |
    115 V Power Supply|L     3 |--------------|          |
    ------------------|________|              |          |
         Black                                |          |
                                              |          |
    ------------------------------------------|----------|
         White (Common)
    
    
    
    I appreciate any assistance.
    
    
    
    Andy Kozak
    

    
    This should be wired as:
    
    
             14/2 romex          14/3 romex
    supply ============== wall ============== fan
                         switch
    
    
    Alternately:
    
    
             14/2 romex          14/3 romex
    supply ============== fan ============== wall
                                            switch
    
    
    (In the latter case, I believe you can use the white wire from fan to
    switch as the supply feed, and the black and red as switched returns to
    the fan; just "color" the white wire black in the boxes. Consult your
    local code. )
    
    If you'va already run 14/2 all over the place -- well, maybe you can
    use it to pull the right cable :-)
                         

    
    Oh, by the way -- why don't we move all of this to an existing
    electrical note...
    

    	After reading through these notes and other material on the subject, 
    I've come to the conclusion that the belt-drive unit is the way to go.
    This was due to slower motor speed (via pulleys) that should result in 
    more durability and less noise. 
    
    	For me, it might not be something I have a choice in the matter
    on. The 30" units I saw were rated for use with 2100 sq. ft. houses. I 
    have a 2400+ sq. ft. house which would require at least a 36" fan. All of 
    the 36" fans that I've seen are belt-drive units anyway.
    
    Re: Mounting in the gable
    
    	I have a question about this. I have a continuous ridge vent and
    although mounting in the gable would reduce the noise transmitted to
    the living quarters, wouldn't it also reduce the effectiveness ? What I'm 
    afraid would happen is that negative air pressure would be created in
    the attic by the fan, which would suck warm air in through the ridge
    vent. If true, this would significantly decrease the volume of air pulled 
    up and through the upstairs hall louver/vent.
    
    	If I mounted it in the upstairs hall ceiling, I would think it would 
    draw much more air volume from downstairs (which I assume is the whole
    point) and create a positive air pressure in the attic to push the heated 
    air out through the ridge vent. Am I missing something here or this the 
    recommended installation for homes with ridge vents anyway ?
    
    	Ray

    What you stated is true far as I know. Only way to mount in gable
    end and get the same airflow threw house is if no other vents in
    attic which would not be desired anyway or you ran ducting from
    opening to house to fan itself, big hassle.
    
    Also I would guess there would be a good chance that the louvers
    in the ceiling opening may not open properly when fan starts up if
    mounted in gable.
    
    Another way to lower noise but more expensive would be to use
    a squirrel cage blower. They can move a lot of air with much less
    noise. But they are not typically sold for this application.
    
    One thing I thought about myself was an installation where the blower
    is on floor of attic near the hole at 90degrees with homemade ducting
    to it. could eliminate some or lot of the noise ?? See below.
    More work than ceiling mount shoud reduce noise some, how much I 
    do not know. Ducting would not have to go to gable end itself, just
    go into attic, that helps to cool attic anyway.
    
    
                           maybe3-5'   insulate inside to reduce noise
                        -----------------------+     especially here 
                        |                      |          |
                        f                      | <--------
        towards  <---   a                      |
        gable           n                      |
        end             |                      |
                        --------------+        |
                                      |        |
                                      |        |
    	attic floor-------------------+////////+-----------------------------
                                         36" opening
    
                                         
    
    Note, I have an old belt drive model and it really makes a racket
    because the belt is too loose and cannot be adjusted anymore.
    I need a new belt, but quess what, all the people selling fans
    don't bother to sell belts. My suggestion is make sure you can order
    more belts and go ahead and order one for future use. I would just
    wrap it up tightly in plastic and leave in attic near fan. I know
    I can get one for mine but do not have lots of time to  search all
    over kingdom come for the stupid thing. Getting one for a few bucks
    now may save you a big hassle in future when fan belt goes and
    no one sells your 20 year old fan anymore.
    
    					Harold
    

    re:belt
    
    	Is it a V-belt, like that used for car fan belts ? If yes, any
    automotive parts store can match it if you bring the old one in.
    
    	Also, was the unit always real noisy or was it significantly
    quieter with a tight belt ? I'm not expecting a whisper quiet fan.
    The sheer size of the fan blades alone is enough to let you know there
    will be some noise. Nature of the beast I suspect.
    
    	Ray

    I bought the house with the fan already there. The noise is due
    to the belt being too loose, and adjustment is at limit. I know
    I can find one, but right now it is not important because we installed
    central a/c anyway. I would assume that unit's original noise
    was only from blades themselves. I just brought it up to say why
    not get an extra belt for future when it is easy instead of
    having to search around later.
    
    Speaking of blades, depending on design of blade you could have
    two different fans with same capacity to move air but drastically
    different noise level due to blade design.  Out in arizona old
    homes used the old swap coolers (evaporative coolers), most
    had squirrel cage blowers, even though they push on average 2 or
    3 times more air than a typical 36" whole house fan they made
    much less noise. Of course do not think about an evaporative cooler
    in humid east, if you did you would really know why they are
    called swap coolers.
    
    

    re:101

    	Thanks for the note on the evaporative coolers. I've seen them
    before and wondered why they weren't used out here. After reading your
    note, it makes sense why they don't. Probably hard to have effective
    evaporation when the humidity is 80% and up.

    	The squirrel cage blower also sounds like a neat idea. I wonder why
    you don't see more of them as whole house fans ? I took a glance
    through my Northern Hydraulic and Harbor Freight catalogs and didn't see
    any squirrel cage blowers. Any idea where I can find one large enough
    to equal or exceed the CFM of a 36" standard fan ? Just seems strange 
    though if they can make a smaller quieter package for the same (maybe
    less) money that they wouldn't be common place .?.
    
    	Ray

    swap/swamp, my mind is going. The evap coolers require extremely
    low humidity to work well. You use to be able to buy evap
    coolers from sears.  I think the main reason you do not see a whole
    house fan with squirrel cage is they would cost more, seems like
    everyone wants to get whole house for real cheap.
    
    I thought one time of using evap cooler with no water hookup, just
    as a blower. But they are so different it would require all sorts
    of modifications. 
    
    I think a standard fan will be fine for you. If you have more than
    one to choose from then see if they have any noise specs to go with
    it. A two speed is nice also, once house is cool the low
    speed keeps it cool and reduces noise to very little.
    
    				Harold
    
    

        Are these whole house fans really worth the money?  The only
	time I'm really uncomfortable in the summer is during a heatwave
	when the air outside is as hot as inside.  The rest of the time,
	I put fans in the windows that do the trick quite well.  One of
	the fans is a "whole house air circulator" that cost about $50
	at Walmarts and claims to be 10 times stronger than ordinary
	box fans.  Its great!  Cools off a hot room in seconds.

	So... how good are these whole house fans in a heat wave?  Will
	they bring up the cool basement air if you don't open any
	windows?  We have a 2 story, 4 bedroom colonial.

	Karen

They don't do much good if the outside air is unbearable.  What they can
do is bring in cool air from the outside in the morning or at night, cooling
off the house (and attic) which will make it stay cooler during the day.

You MUST allow outside air to enter when using a whole-house fan, or else
you create a very dangerous situation that can cause boilers and furnaces
to kill you.

					Steve

> You MUST allow outside air to enter when using a whole-house fan, ....

	And not only that, you'll basically get the same situation as when
	you cup your hand over the vacuum.  Ie. you'll strain the motor
	on the fan and the fan will shut off when it overheats (my fan
	has this protection, if yours doesn't, then you risk fire).

	I just bought/installed my whole house fan a few weeks ago
	(ie. after the last heat wave) so I haven't used it yet
	during a heatwave, but I've found the nighttime temps outside
	are always lower than the indoor temp.  Plus I oversized my
	fan (36" belt drive for I'm guessing 1,000 sq ft living space)
	so I get a nice little breeze moving through.

	And don't forget, when the whole house fan is running, it also
	acts effectiving as an attic/gable fan by pushing the superhot
	air in the attic (hotter than outside air when the sun is out)
	outside.

    They do little when hot and humid. They help a little because
    attic is usually cooler because large volume of air going threw it.
    But if attic is vented properly and floor well insulated then this
    affect is very little.
    
    They work very well on hot days followed by cool nights. Typically
    when air is much dryer like a few days ago. But even then with
    long days the temperature does not drop that fast. With the one's
    I've used over years you typically fell asleep in hot room with
    noisey blower, then woke up later freezing. I never had a timer
    to turn mine off.
    
    Like said before you have to leave windows open. I know for many
    people central a/c is not a valid option but besides the fact it
    works great, other benefits not always talked about that can be
    significant are you keep you windows shut. This helps in two areas,
    one your house is not open for burglars all day and you are not
    sucking in all of the great outdoors dust etc.
    
    My experience with cellars is leave them closed up with a small
    dehumidifier running to keep it dry. Area will stay comfortable and
    for many people is an excellent retreat when upstairs is so hot.
    A cool but uncomfortably clammy cellar can be turned into a nice
    cool and dry area with an inexpensive dehumidifier running just 
    on low as long as you keep it closed up. Has worked great for
    us on various houses. 
    
    				harold
    
    

    I don't know about your dehumidifier, but mine heats up the air as
    leaves the unit.  net net is that the basement is now dry (Very
    happy!), although it is a bit warmer.
    
    -jon
    

    Yes, that is true, a dehumidifier does heat up the air, but that
    is usually ok in a basement, the air gets a little warmer but overall
    more confortable because the drop in humidity offsets the slight
    rise in temperature. But that is why they are useless upstairs,
    close off rooms and turn on dehumifier for a few days and you
    will have a sauna. If the basement has a lot of the wall area
    exposed then the basement may not be cool enough to use one without
    heating up the air too much. When using one only set the humidastat
    to a seating that removes enough moisture for comfort, if you set it
    too high the extra dryness will not offset the extra rise in
    temperature. 
    
    In my case my previous basement was so humid it was useless. I even
    had some stuffed damaged because of the humidity during the
    warm spells in summer. basement was cool but clammy and not
    comfortable. After putting in the dehumidier, the basement became
    very comfortable even though a little warmer. The air was
    also much better for things being stored down there. Our house
    was an old home that the original living area was built in the
    cellar. The house above was built later when they had money. So
    we had a bunch of finished rooms downstairs.
    
    				Harold
    
    
    

I agree - I run a dehumidifier in my basement and even if the upstairs is
in the upper 80s, the basement is in the 60s.  Very comfortable.

					Steve

This note string is pretty old, but I'll give it a try...

I just installed a fan in the attic to control a condensation
problem.  Currently, it is wired to a switch, but I would like
to install a humidistat to automate the process.  

The problem is no one in this area seems to have the fogiest
idea about what a humidistat is.  I am in Seattle, Washington
(humidity capital of the world ;-)  One hardware store offered
to special order it for me at a mere $120.  Is this a reasonable
price for this item?

I have checked hardware, electronics, and even marine stores
with no luck.  Any other suggestions on places or catalogs to
check?

Thank you in advance for any help,
Edit

Try calling some home heating installers - especially those that do FHA. 
I'll bet they can help.  

George

    A word of caution about wiring any type of automated on/off device to
    the fan. If for some reason the fan is triggered on during the winter,
    you must be sure that a window is open, or provide some other source of 
    fresh air. If not, and the house is tight, your fan will try to draw
    air from wherever it can, including your oil/gas fired heating unit...
    
    Not a pretty sight to see a cloud of soot rise from the basement in the
    general direction of the whole house fan.
    
    If you do wire in such a device, be sure to deactivate it if no one
    will be home to ensure an outside source of air...
    
    Freddie

>    Not a pretty sight to see a cloud of soot rise from the basement in the
>    general direction of the whole house fan.

	Probably a major safety hazard too, since it could suck carbon
	monoxide upstairs from the furnace.

	Roy

.21
    Thank you for the suggestion.  I found one at a building
    supply wholesaler for $22.

.22
>    A word of caution about wiring any type of automated on/off device to
>    the fan. If for some reason the fan is triggered on during the winter,
>    you must be sure that a window is open, or provide some other source of 
>    fresh air. If not, and the house is tight, your fan will try to draw
>    air from wherever it can, including your oil/gas fired heating unit...

We have louvers and other sources of ventilation in the attic.  We
mounted the fan by one of the louvers to discharge the humid air.
Are we talking about the same kind of fan?

Edit

>We have louvers and other sources of ventilation in the attic.  We
>mounted the fan by one of the louvers to discharge the humid air.
>Are we talking about the same kind of fan?

	The previous reply was probably talking about a whole-house fan, not
	a gable vent attic fan.

	Roy

    re: -.1 & -.2
    
    Sorry...yes, I was talking about a whole house fan, which draws it's
    air supply from the living area. I apologize for the confusion.
    
    Now back to our regularly scheduled program...

    We are looking at installing some sort of "attic" fan in our garage.
    The garage is uninsulated and has no ceiling over the cars, just the
    rafters. We are finding that it is getting very hot in the summer days.
    There are two windows in the back of the garage, which we can open but
    then the rain also blows in. There are no roof vents of any sort. When
    I lived in AZ many homes had the round "spinner" type of roof/attic
    vents. The wind turned them and the warm air was sucked out of the
    attic. In the winter they were covered with garbage bags to keep out
    the cold air. This sort of thing would be ideal since no wiring is
    required, but I haven't really seen them used here. Is this a
    reasonable vent to use? We are also thinking of adding a cupola to the
    garage. Could we somehow install a vent under the cupola opening to
    vent the hot air?
    
    Any ideas or experience would be appreciated.
    
    Debbie
    

Add a ridge vent.  Far more effective than those spinner vents - cheaper, too.
Make sure you have some sort of soffit vent on the roof overhang for cool
air to enter, though even without this you'll see an improvement.

				Steve

    The ridge vent is probably the simplest solution.  
    If you install a cupola, sure, cut a hole and let the cupola really
    function the way it's supposed to.  My uncle had one on his garage
    roof, with a rope-and-pulley arrangement so he could open or close
    a hinged door at the bottom of it.
    (This assumes, I guess, that the cupola design is not totally bogus 
    and is capable of functioning as a vent, it's not built strictly for 
    decoration.)
    Depending on the size of the cupola, you might be able to put a small
    fan in the bottom of it to blow out air.  One of the 9" diameter
    computer cabinet fans might be good.

    I'm pondering either a whole house fan or a window air conditioner.  My
    house is a roughly 1000 sq ft ranch.  The original attic access was a
    hole in what was the coat closet and is now a pantry.  Someone put
    pull-down steps over the basement stairs (which make me nervous, but
    that's another issue).  So, would it be feasible to use this original
    opening as the location for the WHF?  Would the closet door need to
    stay open?  In general, does the WHF need to be in a central location?

    RE: .30
    
    I don't see why you can't install a fan in the existing hole in the
    ceiling.  And yes, you would need to keep the closet door open while
    the fan was running.
    
    A central location is best to minimize the distance that the fan needs
    to "pull" the air from.  I have one (louvered opening) in the front
    hallway of my house about 5 feet from the front door.  This hallway is
    in the center of the house.  If there is at least a 10 degree
    difference between the outside and inside temperatures, I can flip on
    the fan and drop the temp in the most remote parts of the house by 5
    degrees in about 15 to 20 minutes.  BTW, I close all the doors in the
    house (including the slider) and crack windows in all the rooms (not
    wide open, just a few inches).
    
    ...Roger...

    You may need to enlarge the opening; I think the minimum fan sizes
    I've seen need a hole about 32" square (you take out a piece of
    one joist and the fan goes between the adjoining joists), but I
    haven't looked at that many fans.
    
    Yes, the door will need to be open.  Those fans move a LOT of air.
    You'll also have to be sure enough outside windows and/or doors
    are open to let in enough air. And you'll have to make sure you
    have enough ventilation in the attic so the air can get out.  I
    think the fan I got requires 5 square feet, minimum.  A couple of
    small gable vents or even a full ridge vent probably won't be
    enough area.
    
    Given that those conditions are satisfied though, they work really
    well.  I'm totally happy with the one we put in a couple of years
    ago.  The only (minor) complaint is the noise.  It may be worth
    spending a bit more to get a really good (hopefully quieter) one.
    

    	I have seen 30" WH fans in which the installation instructions
    claim that you don't have to cut any joists. Does the fan just rest 
    on top of the joists ? I would think that you'd have to cut at least
    one joist and/or nail 2 by X's between the joists so that there is no 
    gap and something for the fan to screw to.
    
    	In my case, it appears that I'd need a 36" fan for the size of the
    house that I have ( ~ 2500 sq. ft.), so it sounds as though this
    wouldn't be an option anyway.
    
    	As an FYI, I heard that using a WHF with an air-conditioner on will
    burn out the A/C motor, just in case anyone was thinking of using both.
    
    	Ray

You don't have to cut any joists.  The fan sits on top of the joists.  Some fans
come with a skirt that fits over and between the joists, sort of like a finger
arrangement, so that you have an enclosed area around the fan.  Since you need to
keep windows open for a WHF to work, and keep windows closed for AC to work, I'm
not surprised there are problems.

George

    A little off the topic. Would there be any benefit from instead of
    putting a fan in the hole just leaving it open. (maybe screened).
    Wouldn't this produce a chimney effect, drawing the air from the house
    up and out through the attic ?
    
    Mike

    re: .35
    Sure, cupolas on barns never had fans; they worked strictly because
    of the chimney effect.  A fan will just give more airflow than
    normal convection can generate.

    
    	Well, I've read all 284 replies to this topic.  Very informative.
    With respect to the WHF, is the difference in price between the direct
    drive and belt drive worth the money? Currently I can get a 30" direct
    drive Leslie fan from Home Depot for $125.  The 30" Belt drive model is 
    $175.  I believe the only difference is that the belt drive includes a 
    2 speed wall switch, instead of a pull chain.  Regular fan noises don't
    bother me, and the amount of CFM's are within 200, so I guess we're 
    down to durability (unless the direct drive is unreasonably noisy). 
    Should I expect a belt drive to last longer?  Any other considerations?
    
    	Also, I haven't persued the "Grainger" angle, as the notes
    mentioning it are pretty old.  Can DEC employees still get a discount
    from them?  Can I expect their WHF to be better than the Home Depot
    Leslie fan?
    
    	Also, what about accessories.  Other than the temperature kill
    switch, what other accessories are helpful?  Timers? Dimmer (I didn't
    see a dimmer for the Leslie)? 
    
    	Thanks in advance,
    
    Luis

    re: Grainger
    
    As of a few months ago, I bought a few things at Grainger by just
    showing my badge, no problem.
    
    Don't expect great prices, however.  Their "wholesale" price quite
    often seems to be the same, or higher, than everyone else's 
    everyday price. Not always, but don't automatically think you're
    getting a great deal.
    For instance, Grainger sells Gentran transfer switches for something
    like $320 "wholesale."  I got one at Maynard Supply for $215, and
    Home Depot, if you can stand to do business with them (I can't), 
    had them even a bit cheaper than that.
    Grainger does have the stuff, however, and my experiece with service was
    excellent.
    

    
    	Well, I just bought a direct drive 30" fan at HQ and was
    wondering some of the same things.  Mostly about the noise
    factor.  One thing we noticed was that the direct drive has 
    a 10 year warranty and the belt drive has a 15.  Seems like
    $50 extra dollars is alot to pay for an extra 5 year warranty.
    
    	Also, can I install the thing _under_ the joists as opposed
    to in_between them?  (I confess I have yet to read this whole
    string yet).
    

Steve,

	Installing a whole house fan under the joists might look a 
little wierd but you should be able to install it on top of the joists.  
The WHF (belt-drive) that I installed in my old house came with a heavy 
cardboard plenum that fit between the joists so that the fan only drew 
air from the house not the attic.  If your's didn't come with one I 
would think you can make one fairly easily.

George 

    
    
    	Ah, on top!  Thanks George, sometimes the best ideas
    are just one cube over :-)
    
    Steve

i'm assuming the reason for installing over or under is to avoid cutting
the joist.  here are two areas of concern.
you want a good seal around the box, so it pulls only house air, not
any attic air at all.  i'd use wood, not cardboard between the joists.
think about the louvered opening for the air.  are you sure the louvers
can open if you do not cut the joist?

once installed, the opening to the fan is a very effective heat removal
device during the winter.  be sure you can cover the fan with insulation
during the heating season.  i built four walls around mine from 2"
styrofoam. they are a little higher than the top of the fan. the top
fits like a cooler chest, sits on top and slight press fit inside.
it is covered with 6" of fiberglass insulation. if you make one like that,
mark the top for the proper orientation or make the box square.
you do not want to fuss with a 47"x48" slab in an attic full of trusses
and assorted stuff.  it only takes a minute to cover the fan and unplug it
every fall, uncover it and plug it in every spring.