Conference 7.286::home_work

Unless you have a fairly new, tightly sealed house, why do you want to remove
the moisture from the air?  Most houses are very dry in the winter and could
benefit from the steam from a shower.  Of course in the summer, you do want to
get rid of it.  If there is an attic over the bathroom, you could put in a fan
with ducting that went both to the outside and to some other place in the house.
You'd have to have some means of switching them.  If that's not feasible, go
ahead and put the vent to the outside.  You only need to run it for a few
minutes after you take a shower, so you really don't lose much heat.  You can
buy air-to-air heat exhangers, which replace the air in a house without losing
the heat, but these are really only usefull for a really tight house.

If you do put in a vent to the outside, make sure that you put the outside
exhaust lower than the intake in the bathroom.  If the exhaust is higher than
the intake, the warm air in your house will rise up through it all day, instead
of just when you are running the fan.

Paul

re: .1

Somehow I don't think that simply having the outside vent lower than the
fan would stop the chimney effect, especially from a second floor bathroom.
Any other opinions? 

Does anyone know of an exhaust fan you can buy that somehow seals up the
vent opening when it's not running?  I've been casually looking for one for
a couple of years now, with no luck.

-joet

BTW - The guys who redid my bathrooms a couple of years back didn't vent
the exhaust fans at all!  Downstairs, it just whirrs, and sucks the moist
air into the suspended ceiling.  Upstairs, it spews it into the attic.
MOST unsatisfactory! 

re:.0
Conserving heat, eliminating moisture.
A possibility is to exhaust the moisture laden air to the cellar, living
quarters, or wherever else the warm/moist air is desired.
                                  
Another possbillity is a muffin fan (got a wood or coal stove ? )installed
in the door way. Blows warm moist air into the living air, and the dry col
air returns into the bathroom automatically.

(SOme people with wood or coal stoves have several "muffin" fans throughout
their house. This particular fan is very efficient, and very quiet for its
efficiency.)

								Bob


re.2
Generally, many vents come with a flap, such as for kitchen vents (the vent
has a switch connected to teh vent cover, such as when you release the vent
cover to open, the fan runs. (Stops when the vent is closed). Another
flapper type (for CLothes dryers) operates at two times : the first when
the dryer is actually running (as designed). The other is when the cold winds
outside are blowing, and the air pressure outside the house is lower than
inside the house (caused by the wind blowing across the vent - the venturi
effect if your into Physics).

Two years ago when I wast roding my bathroom, I installed a combination
exhaust/heat/light fixture in my bathroom.

With independant switches I can either suck the moist (yet still warm) air
out of the bathroom or turn on the heater (which recirulates the air in the 
bathroom).

It may not be the most heat efficient device but I love it. On cold mornings I
hit the heater switch so I can shave in a warm bathroom. Then as I take my
shower I put the exhaust fan on (by itself) to prevent the room from fogging up.
Once I'm out of the shower and the moisture is pretty much gone, I then switch
the heater back on as I towel off.  - One of my better investments!

The unit I have is made by Nautilus and I've seen it in a number of home
center / hardware stores for about $80.

Bill C.

re: .4

"wast roding" is a logical for "WAS RE-DOING". Sorry.

bc

Regarding .4

	That is what I put in also, however I put in a heat lamp instead of
the heater. I really makes a morning shower pleasurable. They are really not
that hard to install and there really is not that much of a heat loss through 
it. I had to run mine through the roof but could run it out through the side.
Feel free to contact me for more info...



						Robert

I was looking at a house in Canada last year.  The houses up there are now
built very energy efficient because of the cold temperatures.  Well, the
house had grills in most of the rooms with duct work leading outside.  
There was also a "humidistat" which senses the humidity of the house.  If 
I remember correctly, when the humidity gets above 50%, duct fans will turn
on to exhaust the moist air outside.  Then when the humidity drops to the
desired value, the fans stop.  My first reaction to this was "Gee, you must
be wasting a lot of energy by exhausting all this heat outside".  But it
was explained to me that a house containing less humidity requires far less
BTU's to heat the air, thus the end result was less energy consumed.

This was not a sales presentation.  This house is owned by a close friend.
He showed me that, before the installation of this exhaust system, the 
window sills were beginning to rot because of the high humidity.  There 
was also other damage taking place in other areas of the house.  But after
the system was installed, they felt more comfortable and all the undesirable
condensation stopped.  

All tightly built houses can have a high humidity problem.  The humidity 
comes from people, plants, and water evaporation from sinks and bathtubs.
I have not had a humidity problem because my wood stove keeps the humidity
so low that I have to run a humidifier most of the winter.

Anyways, in answer to your question, the only bathroom fans that I have 
seen are the ones that exhaust the humid air outside or in the attic.

BTW- In my opinion, exhausting moist air into your attic is acceptable. 
This is because your attic should be vented well enough to disperse the
moist air outside quickly.  However, exhausting moist air into a suspended
ceiling seems like a very bad idea.

Denis

  
  leave the door open..

    ..Paul :-)
  

Well, all these folks have told you a lot about venting fans.  I think 
they are a great idea.  Etc., etc.

Another thing you might consider for a bathroom is paint with mildacide 
in it.  Bathrooms are going to get soggy no matter what else you do.  
The mildacide supposedly stops the mildew buildup in its tracks.

Anybody have any opinions on mildacide?

- Paul

re; .9

What is the 'trade name' for "mildacide" and what type of stores carry it
for about how much money ?

							Bob

Any good hardware/paint store will have it.  I don't know the trade 
name, but the stuff gets mixed right in with the paint at the store.  It 
costs about $1.50 to add it to a gallon of paint.

- Paul

I wouldn't be surprised to find that "mildacide" is some variant of
formaldehyde or some other deadly chemical.

I've become especially aware of this aspect of high-tech home materials because
of my wife's allergies.  For example, her allergy doctor told her that her
new kitchen must be built with real wood - no particle board, not even plywood.
The problem is too much outgassing of noxious chemicals.

-- Ward

I washed the ceiling of a bathroom with the black junk (mildew) on the ceiling
with a diluted solution of chlorine bleach.  It took off all of the mildew
and killed the stuff as well.  Be sure to use some rubber gloves when you
use that stuff since your skin doesn't particularly like it. 

If you're going to vent humid air into the attic space, do it where it will
be exhausted quickly.  Otherwise it will condense on the roof sheathing and
cause mildew there.  Of course, if you don't go in the attic you won't see
it.

Just my $.02 worth.

Bruce Bretschneider

Ok, I bought a fan last night (no light or heater).  Where do they
normally locate it in the bathroom?  Over the shower or about in the
center of the room?  Seems to me that the best place is over the shower/tub.

	I'm no expert, but it seems like it would get too heavy a dose of
water if you put it over the shower.  The electrical code may not think too
highly of that either, but I'm really not sure.  The one in our house is
kind of in the middle of the ceiling and I still have to clean the rust off
the motor shaft occasionally (about 6 months).

						- Rich

I recall seeing something in a recent Consumer's Report about heat exchangers:
as hot air flows out, it is used to heat the outside coming in.  They are
passive devices (I think) which is a plus.  I'll recheck the article and if
there's any new and interesting stuff to add. 
\bob

I believe that .15 is correct in suggesting that you should check your
local electrical code first before installing over your bath/shower area.
Even given that your entire bathroom in hopefully on a ground-fault 
circuit, electrical appliances/outlets should be kept out of reach when
you are in water.

Charlie/

I believe the national electric code says that wall switches must not
be within reach from within the tub/shower, but does not specify
the same for lights/fans/heaters. If you deem that the fixture should
be on the ceiling, but close to the tub for logistical reasons, then
that is okay code-wise.

Dave

    I have a question, I'm converting a bedroom into a bath and have
    put in a ceiling fan. Now my other bath has a ceiling fan which
    is vented by a 4" duct hose to under the soffit vent thus venting
    the air outside, the run of the hose is about 3 feet. Now my question
    is, should I do the same for the new fan or should I run a vent
    stack through the roof. If I was to vent the fan to the soffit like
    the other fan the run of the hose would be about 10 feet. If I run
    it through the roof, the run would be about 5 or 6 feet vertical
    with a couple of bends in it, does it matter which way I do it.
    I want to do it right, but if I can just run the hose to the soffit
    vent and lay it on top as the other fan, I rather do that. it would
    save me from cutting throught the roof. Also the roof vents I've
    seen are only at the most 6" high and would get covered with snow
    in the winter, thus not allowing it to vent anyway...
    
    
    Any opinions would be greatly appreciated.
    
    
    
    Royce

I can't think of any reason why shortening the hose by 4 ft would be worth 
cutting through the roof.  I'd go ahead and vent out of the soffit.

Paul

      Since you are looking for opinions, I also would not go through
    the roof.  If it's vertical, then it would seem to me that some
    of the moisture will condense (much more so in the winter) and drip
    back in.
    
    -Jim
    

    Another reason for not going vertical is that such a run acts as
    a little chimney, sucking warm air out of the house all the time
    (even when the vent fan is off).

    The snow melts away from all the warm air escaping through the vent!
                        

    I had to make the same decision when I installed a vent. Here's
    some things you must think about:
    
    	Do you realy want to make a hole in a other wise leakless 
    	roof? Therefore creating a possible leak?

    	Is there going to be a condensation problem in the vent pipe?
    	Where will it go?
    
    For me, I put the pipe under the attic insulation to cut down the
    condensation and installed a sofit vent so I wouldn't cut the roof.
    Don't forget to put a realy good screen on the outside. Wasps love 
    to make **BIG** nests in a four inch pipe.
    
    Richard.
    (Don't ask how I know about the wasps)

    Are the soffit vents for the exhaust fan similar to a dryer exhaust
    vent?  Do they have a cover that opens and closes or are they just
    covered with screen?
    
    Phil

    
    Is it better to install the fan in the ceiling of the bath or on
    the outside wall?
    
    And how the heck to you make a nice neat 4 inch hole in plaster?  Is there
    such as thing as a 4 inch hole saw you can attach to your electric
    drill??
    
    -Steve

    re: .7
    
    A drywall saw for the plaster.  Drill in the middle first, insert
    the saw and cut.  A sawsall (?sp) for the outside wall or a small
    hand saw (the kind with a point) if you don't have a friend with
    a sawsall.
    

    I saw an article someplace that said the best place for the exhaust
    outlet was about halfway down the outside wall, so the hose from
    the fan runs across the ceiling, then down inside the wall and out.
    The reasoning is, hot air rises, cold air falls.  By putting the
    outlet loser than the inlet, in wintertime there will be no chimney
    effect and warm air won't get sucked out of the house (except when
    the fan is on).
    But I think you'd probably have to do it this way when the house
    was built; it would be quite a job to retrofit.
    
    

    Take it from a person who has had experence, there will definetly
    be mosture condensing in the hose or pipe.  I went through the trouble
    of venting mine through the roof and after about 2 months of cold
    weather I noticed a discolorization in the ceiling next to the vent.
    The bend in the hose had filled with water and was leaking into
    the ceiling.  
       
    Since then, I have read in a number of publications that the best
    location for a vent is closest to the outside wall.  In addition,
    the vent hose should be kept as straight as possible.   I would
    have to agree that the best way to go, is through the sofet.
       
       
    Kev                       

    Thanks for all the replies, I'm going to run it to the soffit, ,it
    is pretty much of a horizontil run, I'll do it this weekend before
    I sheet rock.
    
    
    
    
    Royce

    I am not sure that anyone will be able to answer this, but I
    figured I'd try anyway.
    
    I hve been having problems with rust in the bathroom because
    it has been so damp in there since the humid weather has
    began.  The rust is showing up on the baseboard heaters
    as well as around the the rim of the sick in between where
    the metal meets the vanity.  I cannot get rid of it and
    wonder if there is any solution.  I realize that the 
    heaters will have to be scraped and repainted, but
    what can I do about the vanity surface?
    
    Any suggestions?
    
    

    Get an exhaust fan--install it right in the shower. The best one
    would be the through-the-wall kind they make for kitchens.
    

    There is a product called Rust-B-Gone which I used with success
    on a chrome alloy surface which was then sealed to prevent further
    rust.  It was purchased in a local independent hardware. 

    
    	RE .1
    
    	You cannot use a kitchen fan for exhaust in the bathroom unless
    the fan has louvor(SP) doors that open automatically and has NO
    pull chain. Hanging chains are not allowed in the bathroom, I know
    from first had experience. 
    
    	-Steve-
    

    If you go to State Lumber company in Holliston, Marlboro, or
    Saxonville,you can aask to see the book they have on Miami Carey
    bath fans.  I know there is one out there that seals in the air
    flow
    in the winter months.  Otherwise, if you have problems with mildew
    and such, there is a product you can mix into regular paint called
    mildewcide (there may be an equivalent).good luck
    
    bren
    
                                        

    I recently found out that is your bathroom ceiling is painted with
    white house paint it will resist mildew -- the reason is that house
    paint is far more durable and resists climate changes far better
    than interior paint.
    
    It really does work -- just be sure all mildew is removed before
    repainting.
    
    	Terri
    

1-1/2 years of inactivity, seems like a reasonable amount of time to wait to
reactivate this - besides there are lots of newer opinions.

I have just installed 2 vent fans in back-to-back bathrooms.  I'd like to know
what people think about venting them through a single vent using a "T".  My
biggest concern would be one fan blowing into the second but there is a check
valve (actually a flap) on the outlet of the fan that should prevent this.

Having reread all the other replies, I guess the other biggie is condensation.
I was thinking about venting through the roof (I don't really think a leak 
should be an issue if you do a reasonable job of flashin AND since I'm in the
process of re-roofing I've got lot's of extra shingles.  At least going straight
up any condensation will immedately fall back down and not accumulate.

I like the idea of a soffet vent more, but that would require close to a 20
foot horizontal run and I've gotta belive a lot of condensation would build up
in there over the winter.  For those who have done this, isn't condensation a
big problem?

-mark

Didn't read the earlier notes, but I can share my bathroom vent experience...

We were getting a loud flapping noise in our bathroom vent last winter.  We
had been in the house approx 1 year. (new construction.)   I figured it was
the flap on the outside vent cover, so I climbed out on the roof to look.
The flap wasn't flapping.

I took the vent apart.  Couldn't see anything wrong.

Finally went up into the attic (no small task...entry through a 2x2 hole
over the closet shelves! 8-(  ) and the damn builder had vented the damn
fan though dryer hose STRUNG ALONG THE ROOF TRUSSES WITH TAPE!!!

Naturally, the hose was full of water.  I poured out about 2 qts, buried
the hose in the insulation (I'm sure the builder just forgot to do it...
there was plenty of slack in the hose) and its been working fine ever since.
____________________________________________________________________________

As for putting a "T" in the line to vent the two bathrooms, I would be more
incluned to use a "Y"... this way you can prevent the air from pushing
directly on the flap from the other fan, and avoid possible problems with
simultanious use.  Of course, I'm no fluid flow expert... but I think it
could work.

Bob

    I agree--bury the hose in insulation and there will be minimal
    condensation to worry about.
    
    Mike

    
    
    re: last couple
    
    shouldn't you vent it out of the house?
    
    Steve
    "just wondering"    
    

>    re: last couple
    
>    shouldn't you vent it out of the house?

Yes... The hose is buried in the attic insulation on its way from the 
bathroom ceiling vent to the outside of the house.   Sorry if that 
wasn't clear.  8-)

Bob

sounds reasonable to me.  I gather that the moisture that will condense when the
hose comes up out of the insulation will be minimal...

re: a couple of back

was the comment about the builder who used dryer vent hose intended to imply one
shouldn't use that?  I had planned on it...

re: a "Y" connector

of course!  I hadn't even thought of it but it makes perfect sense to me.

-mark

re : dryer vent hose...

Dryer vent hose is fine, as far as I can tell.  Just has to be insulated,
or burried in the insulation.   Condensation for the 11" or so that 
goes from the insulation to the vent seems to be minimal, or may just flow 
back into the bathroom  (haven't seen any puddles or anything, so I guess
it minimal at worst)

My original problem was because of the way the dryer vent was taped to the
trusses.   Imagine a big "M"....  Leaves a very nice spot for the water to
collect in!  8^)

Bob

    
    I just installed a fan for my tenents side of our 2 family house.
    I had installed one in my about a couple of years earlier. The hardest
    problem was running the damn vent to the eve. So for my tenents
    I bought a PVC "Y" connector and just hooked their vent up to ours.
    It worked out great. Took me about 10 minutes to hook up the hose.
    The hardest problem this time was running the wire for the electrical.
    When pulling the line through, the stringer broke 8*( ; What a
    bummer!!!! Took me about an hour to fish a new line through.
    
    Mike

Does anyone know of a replacement bathroom exhaust fan/light 
combination that, using the existing 2-wire switched line,
enables one to individually control the light and/or fan?

I know such "smart" switching is offered on ceiling fans -
Casablanca, for example.

    I don't know of one you can buy this way, but you can modigy your
    existing one using the BSR-X10 system from leviton  to do it. There is
    a conference out there somewhere on the x-10 system or if you want call
    me at DTN 352-2184.
    
     Bill
    

    Looking for some suggestions:
    
     My upstairs bathroom ventilation fan may need to be replaced. 
    However, I can't see how it is mounted.  It seems as though it was
    put in and then the dry wall was put in so I can't see where it
    is anchored. Any tips of how I can get it out?  Also, the ceiling
    is at an angle and the fan cover doesn't snap into place...  If
    I did manage to get it out through any advise, how could I get a
    new one in and nail or screw it in place?  Any help would be
    appreciated.

    I think more info is in order (manufacturer and model # would help,
    so would age). The unit I have can be taken apart by first removing
    the cover over the bulb, followed by a nut that retains the bulb
    asmy, followed by two screws that retain the fan asmy......... It
    appears that the actual mounting case is attached to the joist though.
    Yours would probably vary, so start by taking it apart, till you
    only have a case left and then study it to see how its mounted.
    
    Eric

    Where, in E. Ma or S. N.H. can I purchase an energy efficient 
    bathroom exhaust fan. That is to say, when the fan is not running
    no air is able to pass into or out of the house.
    
    Thank You, Jim

    I'll second the question. I'm looking for a similar energy efficient
    vent for a kitchen exhaust hood/fan ... ?

    Don't know if this will answer your question but we installed
    ours with a dryer vent on the outside...only opens when air is pushing
    out...
    
    Lynn
    
    

    Can't help you with pointers to stores since I live in Georgia but,
    the bath exhaust fan I put in had little flaps as part of the fan.
    When the fan runs it pushes the flaps out of the way and when turned
    off, they fall back against stops.  Admittedly the seal is almost
    non existent due to the precision of the manufacturing but it it
    better than no dampering.

    	Is there anything else beside making a hole in the wall to let
    the air out.What about recirculating the air,will that help?What
    type will that be.Any suggestions will be appreciated.
         
    				Thanks 
    		Jean-gilles.
     

    A couple of years ago, I installed a bathroom heat/vent/light fixture
    which has a flap similar to that described in .3.  The flap is at
    the fixture end of the duct and will close whenever there is a back
    draft trying to come into the house.  I've never had any problems
    with it.
    
    As to where, I would suggest that you try Standard Electric at the
    intersection of Rt. 117 and Rt. 128 or Mass Gas and Electric in
    either Waltham or Boston.  BTW, I bought mine at MG&E in Boston.
    You probably can find them in any light fixtures store or hardware
    store.
    
    Alfonso

    Thanks for the replys. I am familiar with the types that have the
    sheet metal flaps and that is the type that I am trying to avoid.
    I was thinking more on the order of something that might have a
    cover on the inside of the house that had to be manually opened
    and closed that formed an air tight seal. Also it would be nice
    if opening the cover would activate the fan motor.
                                  
    Thanks again, Jim

    I was looking for something for the kitchen that was a little
    more high tech than the traditional sheet metal flap. Those appear
    to be rather leaky. I hate to put something like that in after all
    those hours I spent sealing things up with the caulking gun.
    
    Anybody know of a source for 80's versions of these items ? 

>    I was thinking more on the order of something that might have a
>    cover on the inside of the house that had to be manually opened
>    and closed that formed an air tight seal. Also it would be nice
>    if opening the cover would activate the fan motor.

what you've described was the latest in technology in 1953.  my mom had one 
over the stove in the kitchen.  it was made by NuTone.

craig

    Try the Brookstone stores they are supposed to have one around $20.
    that will close off the drafts.
    

    What are you trying to accomplish ?    If you have a moisture
    problem in the bathroom, the only solution that I have ever heard
    of is to remove the moisture.  To do that, you have to vent it
    to the outside.  It's really not so  difficult.  I just installed
    two bathroom fans and I don't consider myself particularly
    adept at this sort of work.  If you were to re-circulate the
    air, nothing would be gained.  If you vent the air into an
    attic, or anywhere else within the home, you are only asking
    for more trouble.
    

I had read all these notes quite awhile ago about venting fans through the
soffit and it sure made a lot of sense to me.  Anyhow, I finally got around to
getting a vent to install and lo and behold, nobody makes one - I was
assuming it would look something like a dryer or roof vent only be able to
opern downward.

So what do people do who use soffits?  Simply dump the moist air into the wooden
soffit and let the soffit vent deal with getting the air out?  I'd hope not
since I'd think this would lead to a rotten soffit fairly quickly.

Am I missing the obvious?

-mark

    Mine has a dryer vent in the soffit.  It opens down toward the house,
    so the rain doesn't blow into it.  The only thing is this can't have a
    gravity-closed cover on it (obviously).  The hose from the fan goes
    right into the soffit to connect to this thing.
    
    I don't know if this is the right way.
    
    Elaine
    

	re: bathroom fan venting

	As it turned out, there was a soffit vent right where the hose
	ran along the ceiling joists. I just cut the tubing a little on
	the longish side and wired it to the backside of the soffit vent
	after removing it. It's been that way for 5 years now and
	there's no evidence of moisture damage from the vent air. I take
	the vent off every year and dust off the screening to let the
	maximum air flow.


	If things didn't turn out as they did with the locations of
	vents, I had thought of using a dryer vent, in plastic colored
	to match the soffit color. Remove the flapper and install a
	bugscreen. 


	Chris

    re: .22
    
    Could you be a little more specific?  Do you mean there was a 4 inch
    round soffit vent at that point?  That won't help those of us who have
    the combination drip-edge/soffit vent.
    
    Also, you said you wired it (the vent hose from the fan??) to the
    backside of the soffit vent after removing it (What it??? and when did
    you replace it?).
    
      Gary

    Looks like I checked in here just in time.  I, too, have just installed
    two bathroom ceiling fans, one in the existing bath, and another
    in a soon-to-be bath in our new addition.
    
    I've had people tell me to just vent them over the insulation, that
    since I've got a full drip-edge vent, plus a full ridge vent, I
    won't have any problems.  But, I'm not buying that, unless I know
    someone who did it.
    
    So, I guess the best bet is the Y, with a roof vent.  Too bad, the
    new roof is only 2 months old.
    
    I won't be venting them for another week or so, as the electrician
    hasn't hooked them up yet.  If anyone has additional ideas, please
    reply.
    
    Thanks,  Lee

    I vented my fans through the soffit using 4" round flexible aluminum
    vent tubing from the fan housing into the soffit.  Then, I cut a
     4" hole in the soffit, and attached the tubing to a 4" round
     aluminum soffet vent ( available at Somerville lumber, etc).
     A couple sheet metal screws did the job.
    
    This is the type of vent that used to be popular for adding ventilation
    to soffets.  They are available in different sizes and have a
    built-in insect screen.
                             
    Works fine, keeps the bugs out, and is barely noticeable. 

     Bathrooms have humidity.
     One of the last places that you want to have extra humidity is
    in your attic.
     In the winter time, the humidity will condense very rapidly on
    something and when the stuff melts, you'll have water comeing in
    your home.
    
     Vent the fan outside, small bucks, compoared to a new roof, or
    new insulation, etc...

< Note 1138.23 by TOKLAS::FELDMAN "Week 3: Raising the Roof" >
>                        -< too many dangling pronouns >-
>
>    re: .22
>    
>    Could you be a little more specific?  Do you mean there was a 4 inch
>    round soffit vent at that point?  That won't help those of us who have
>    the combination drip-edge/soffit vent.
					     ^
						Nope, it won't help in
						your case. You're stuck
						with going thru the roof
						or using a round vent 4"
						or whatever to fit the
						vent hose.

>    
>    Also, you said you wired it (the vent hose from the fan??) to the
						^
						yes, the vent hose

>    backside of the soffit vent after removing it (What it??? and when did
         ^
	 yes, to the back side of the rectangular soffit vent

>    you replace it?).
	          ^
		  after connecting the vent hose to the backside of the
                  soffit vent, the rectangular soffit vent was refastened
                  in its original position.


That clearer now? It is Monday isn't it?   ;-)

re: 4" round soffit vents

I've seen these and quite frankly prefer not to use them, specifically because
they don't have a flap and stay open all the time.  It would seem to me in the
winter (especially) I'd want to do all I could to keep cold air from blowing
into the bathroom and having 2 flaps (on on the fan and one in the vent) would
be ideal.

It sounds like a dryer vent with a spring loaded flap may be the best way to go.

re: Y's

There's no such thing, at least not any made for this purpose.  I've been to a
lot of places and nobody has ever heard of them.  My next approach is to go 
after a standard 4" Y for PVC.  Only thing is the kind for waste pipes are
close to $10 apiece.  My plan is to find one for PVC drains (the kind you put in
the ground) which only cost around $2-$3.  The next obvious question is how
easy will it be to attach the vent hose since these are probably 4" ID and you 
won't be able to put a clamp around the hose and Y.  Might one be able to run
short pieces of PVC into the Y and clamp hoses to them?

-mark

    The vent fan I have in my bathroom has the flap inside the fan housing,
    so one doesn't appear necessary on the soffit vent itself.
    
    Eric

Athough one is't probably necessary, neither are storm windows.  I simply would
like to maximize the seal whereever possible.

-mark

    When I  bought  my  house,  the  bathroom  fan was vented into the
    attic.  For  all the reasons in the last few notes, I added a roof
    vent  for  it  and  connected it with dryer hose. This has cut the
    airflow  tremendously.  It's a relatively short (less than 3 feet)
    piece  of  4"hose. What can I do to get more airflow from the fan?
    Right  now  it  takes  forever  to  get  the  moisture  out of the
    bathroom.

--David

    Experiment a little to determine where the airflow restriction is.  The
    most obvious place is in  the  hose and the roof vent.  Corrugated hose
    has  an  surprisingly high airflow resistance  per  foot.    You  might
    temporarily try each of the following, and see if the airflow improves.
    
    0) Slightly open bathroom window to make sure replacement air can enter
    bathroom. Close window before going to 1 and 2
    
    1)  Disconnect  from  roof  vent and allow hose  to  vent  into  attic.
    (checks roof vent pressure drop)
    
    2)  take  hose off of fan outlet and allow  fan  to  vent  into  attic.
    (checks hose pressure drop)
    
    IF 0) makes the most difference, you have to find a way to let air into
    the bathroom..
    
    If 1) then check for trash in the vent, bugs etc.  as a last resort you
    may have to modify the vent to give less pressure drop.
    
    if 2) then check for kinks  in  the  hose, or low spots where water has
    condensed and formed a kind of water trap.  If this doesn't help replace
    the hose with one of a larger diameter or use rigid metal duct if at all
    possible, even if you have to miter the the  joints  and  connect  them
    with very short pieces of hose.
    
    Depending on the airflow characteristics of your  fan,  you may be able
    to get much more flow by a very  small  decrease  in pressure drop, and
    vice versa.  A graph of air volume delivered by the fan VS pressure the
    fan must work against is usually very non-linear and can  even  reverse
    on itself, So it can pay to make improvements even if  they  seem  like
    they won't make much difference.
    
    Oh yeah, it  might  pay  to oil the motor, and check that the damper in
    the fan housing opens freely...
    
    
    gjd

re: .22

>	I take the vent off every year and dust off the screening to let the
>	maximum air flow.

If this is really true - if you really get up on a ladder once a year to do 
this - then you're a far better man than I.  :^)

Paul

    Regarding the issues of over-shower fans being to code,
    there are specific brands that are certified to be used
    inside the enclosure. We found a Nutone model especially 
    designed for use directly over a shower/tub at Marlboro
    Electric, with light and heat optional.(~$120) The issue isn't just 
    code, although that's obviously most important. Using a fan 
    that isn't designed for that environment of heavy moisture 
    will greatly reduce the life and performance. 
                                    
    We put one in our former house to remove excess moisture, which 
    condensed on the ceiling (especially in winter - above it was 
    unheated attic) and grew black mildew/mold. My husband and I 
    installed it ourselves, and because it was directly over the shower, 
    we ran it only when using the shower - no more mildew!    
    
    We ran the exhaust hose (dryer ducting) through the attic and 
    out the side of the house over the bathroom (the side because
    we didn't want any more leaking holes cut in the roof). We noticed
    after a winter that the fan was making much more noise than earlier,
    and from the outside it was clearly running intermittently (the
    external flap was opening and closing while the fan ran.)
    Investigation in the attic found that where the hot, moisture
    filled air ran through the chilly attic, moisture was condensing
    inside the dryer hose. The weight over a winter or two of this
    condensed water had created a low spot in the hose, and the 
    accumulated water actually blocked the air flow. When we emptied
    it out, it filled two-three coffee cans (a gallon or more?).
    After the discovery, we emptied it every spring. 
    
    To remove the old mildew, we washed it off, and repainted the 
    ceiling with special bathroom paint (recommended by Spag's) that 
    I recall was alcohol based. (It didn't have formaldehyde.)
    
    We wanted the same fan arrangement in our new home
    we just built this summer. However, the electrician didn't
    want to do it, I think because of the cost. We supplied it, 
    he installed it, and the electrical inspector okayed it. 

re: .28

>re: Y's
>
>There's no such thing, at least not any made for this purpose.  I've been to a
>lot of places and nobody has ever heard of them.  My next approach is to go 
>after a standard 4" Y for PVC.  Only thing is the kind for waste pipes are

Was I dreaming when I installed one in my attic? ;-)

I vented two fans from back to back bathrooms. I combined the two pipes
into one using a 4" galvanized Y and then ran one pipe into an outside
vent.

Now, I can't remember the name of the place where I got it, but it's in
Nashua on E. Hollis St. If you're going towards Hudson, you stay to the right
instead of curving to the left for the bridge. They do all sorts of
sheet metal work and have lots of supplies. Unfortunately the Y only
came in galvanized, not aluminum.

Ken

    
    re .28
    
    re ."y's"
    
    I bought a PVC Y also because I couldn't find anything made for
    that purpose. I went to several building supplu houses. The PVC
    works great.
    
    
    Mike

    And I just did mine yesterday.  Used the PVC Y, just ground the
    bumps on the sides.
    
    Seems to be working just fine.  Got the Y at Grossman's.
    
    Lee

    Now that my fans are joined with a PVC "Y" (3", not 4"-the aluminum
    hose fits over the Y ends), I've got to vent them to the soffit.
    
    The depth of the addition is 16'.  So, I'd like to run 3" PVC from
    the "Y" to the soffit, then vent it out at the bottom of the soffit.
    I plan to have the "Y" mounted on a rafter, then follow the roof-line
    to the soffit which will give me a nice downward pitch for any moisture
    that gets settled in the pipe.
    
    Has anyone tried this, or know of someone who did?  What were the
    results?  I've got to make my decision soon, as I'm getting ready
    to close-in the new rooms.  I DON'T want to open them up again for
    some problem with the venting.
    
    Lee

    
    Just to finish up on .34, the name of the place on East Hollis street
    in Nashua is Total Air Supply.

    after building our house we had the bathroom mildew problem.  we had
    our electrician come back and install an exhaust fan.  for about a year
    the mildew problem remained.  in desperation (becuase we wanted to
    paint, etc.), i went to the attic to see if the flexible vent tube was
    clogged.  it was fine.  however, in the fan housing was a plastic flap
    vent intended (i suppose) to keep cold air from making it's way into
    the bathroom.  it would open under air pressure from the fan.  well, it
    was so poorly designed that it would only open about 10% of it's
    designed capacity.  it seems that the inability to exhaust the damp air
    from the bathroom was due to this.  i've taken the flap valve off and
    will see if cold air makes it's way into the bathroom this winter.  if 
    you install one of these units and it doesn't seem to be doing the job
    then check this valve. 
    
    
    

    You might want to reflect on whether the purpose of the flap is to
    keeps more than just cold air out.
    
    
    				herb

	We have to put a vent in our upstairs bathrom, also.  But
the ceiling is a radiant heat panel which I am not suppose to cut!
(All the ceilings in our home are radiant heat panels - this is our
back-up heat for a passive solar house.)

	So, any suggestions on how I an can install a vent in the
ceiling?  The exterior wall in the bathroom is north facing and I
will not instal a vent in a north facing wall.

Douglas

    Why not install it in an interior wall and vent up through the
    attic or roof, that way you will not cut one of the radiant coils
    in the ceiling. I assume there is some method and space to place
    junction boxes for lights or smoke detectors in the ceiling. If so
    you may be able to cut a 3 to 4 inch hole and put in a duct that 
    feeds a fan in the attic or better yet a whole house ventilation system.
    
    Don

    I have read through these notes and I do not remember finding a
    solution to our problem.  We want to install a bathroom fan and vent
    the moisture out from the attic, but the only problem is that we do not
    have any eaves above the bathroom.  So what this means is that we would
    have to run some sort of tubing through 3/4 of the attic until we can
    vent it through the eaves (which we really do not want to do.)  Any
    alternatives?
    
    Jean
    
    P.S.  I thought that I had read of someone who had a similar problem a
    while back, but I could not find it.

    If the run to the eves is as long as you suggest, it is highly likely
    that the fan cannot push the air that far anyway.  Run the duct
    straight up and out the roof.  You can buy hoods for duct work so that
    debris does not fall in.  

    15 minutes with a saber saw, a metal collar, a squirt of roofing tar, a
    couple of nails and you are in business.

    	How about venting the bathroom INTO the house during the winter
    	months? This may provide some needed humidity.
    
    								Neil

    	Hi,
    
    		I want to add a fan/heater combination in my bathroom. I
    have a choice of using heat lamp or resistance wire type for the
    heating function. Can anyone explain the pros and cons of each type of 
    heating (lamp vs. wire)? It would be great if this person can also 
    recommend a brand name or model number.
    
    		I'm sorry if this is a repeated topic. I search the
    directory without any luck. Maybe my question was answered in one of the 
    replies. If so, please point me to the right place.
    	
    		Thank you.
    
    								Neil	

The lamp type heats you by radiation - when you stand under the lamp, you
feel warm because your body is absorbing infrared light.  It isn't very
effective at warming the air in the room, but especially for bathrooms, this
is more than adequate (and takes less power).

A resistance-type heater is usually coupled with a fan and warms by convection,
heating air and moving the hot air through the room.  You may still feel
cool upon emerging from a shower, unless you have had the heater on for
a long time.

My preference is for the lamp type of heater in bathrooms.  With one, there
is little need to heat up the rest of the house (or room) just so you can
be comfortable when emerging from the shower.

There are many brands on the market - I recently picked up a Miami-Carey model,
but I've also seen Broan and Nutone.

The lamp units are 250W per bulb.  The resistance type elements are usually
1000W or more, and may require a dedicated ciruit.

				Steve

    	Hi,
    
    		Thanks for the suggestion. I just talked to a co-worker and
    	he pointed out that I can replace the bulbs easier than the heating
    	element. At this time, I incline to buy the heating lamp type.
    
    		Thanks.
    
    								Neil 

By the way, if you are in the Massachusetts area, the "Building 19" store
in Burlington had a pile of 250W heating bulbs for $2.99, which is half
the normal price.

			Steve

    
    The heat lamp will heat your body, while you're under the lamp, and will
    have the most effect on your head and shoulders.
    
    The air heater will heat your whole body, reduce the relative humidity
    in the room, and defog the mirror. I've been using one for 13 years and
    haven't replaced a heater coil yet.
    

	
	Like others in this topic, I installed a bathroom exhaust fan in 
the ceiling and ran the ductwork under the attic insulation across to the 
soffit and out.  Unfortunately, after one winter season of use, the 
plastic ductwork has filled with condensation (I presume) and the exhaust 
is blocked.  This, I believe, is due to the fact that the ductwork has
to come up out of the insulation to get over the exterior wall top plate
prior to venting through the soffit (rough sketch below).  When the warm
moist air in the duct is exposed to the cold, it is condensing and 
laying in the ductwork.


          ductwork under insulation        //===== <--- exposed ductwork
          ================================//|   ||
          || 		                 ^  |--------  <--- vented soffit
	<<<>>>			         |  |
         fan			condensation| <--- exterior wall
				forms here  |


	Anyways, I had an idea (read 'oh-oh, somethings gonna get busted)

  	The main plumbing vent pipe which extends up and out the roof is 
nearby.  I was thinking of running the exhaust ductwork over to the plumbing 
vent pipe, and joining with a T.  I would be able to keep all the ductwork 
under the attic insulation, the exhaust would go out and up the plumbing 
vent pipe and any moisture would then, hopefully, accumulate in the 
plumbing vent pipe and not the exhaust ductwork.

	Anyone see any problems with this approach ?

						-Ian

    Re: 1138.41
    Couple of points: First,plumbing code will not allow it.
    
    Second,the vent pipe is needed to let gravity move the water,i.e. allow
    a place for the displaced air to go. The vent will effect the pressure
    hence,effect the way that the water drains.
    
    I wouldn't do it.
    
    Marc H.

    re1138.41:
    
    If you do it, make sure the fan is moving the air in the right
    direction :-) :-)!
    
    Steve

    
    	Ya, I suppose your right about the plumbing codes and the pressure
    and all that Marc.  I've never been an expert when it comes to plumbing,
    other than of course knowing the plumbers creed... 'sh*t runs downhill,
    paydays every Friday, and don't lick your fingers'.
    
    	And having the exhaust reversed (re: 1138.43) gives new meaning to 
    the phrase about things hitting fans...
    
    	Any brainwaves?  I've thought of wrapping the exposed exhaust duct
    in insulation as it comes up over the top plate to the soffit, but 
    its such a tight squeeze (ie., trusses meet the top plate here) I don't 
    think I could manage.  And I can't get at it from the outside as the
    eavestroughing is over the facia which holds the soffit in place,
    etc...
    
    	I may end up just disabling this fan and installing another one in
    the bathroom wall.
    
    					-Ian
    

        Hooking up to the vent stack will let sewer gas into the house
        when the fan isn't running!
        
        Since exhaust fans don't do that well at removing humidity, and in
        the winter you need that humidity, get rid of the exhaust fan. Use
        one of the recirculating fans with a carbon filter that need no
        ductwork.

I don't understand why the condensation caused a blockage.  Did it freeze?

We wanted to run it through the soffit, but decided there wasn't enough
clearance to work there.  So we bought a roof cap and ran it through the roof.
The ductwork is rigged so that we don't have to worry about condensation
dripping back into the fan.  We don't worry about the lost heat.  We haven't
had any leaks with the vent itself, but the hot air blowing out of the
vent did help cause a nasty ice dam when we failed to do a good job of
raking the roof.  We'll address that problem with a ridge vent (in addition
to the existing roof vents) this year; if that's still inadequate, we'll go
with electric heater cables to prevent the ice dam.

Granted, the fan doesn't do a really good job at removing moisture, but it
still makes a very noticeable difference, easily measurable by how much surface
area of the mirror gets fogged up after a shower.

   Gary

    
    	Well I'm sure it froze in the winter....maybe I'm jumping to
    conclusions but I'm thinking I have this ductwork in my attic with a
    low spot somewhere along it that is now filled with H2O and the air
    can't get past it.  Isn't that the general problem others have been
    having in here?  I don't know.  I just want to get rid of the damn
    moisture in the bathroom.  Even with the window open (which doesn't
    really thrill me in the winter) I can't get rid of it.
    
    	You mentioned that you ran yours through the roof.  If the
    condensation doesn't drip back into the fan, then where does it go?
    
    	I'm not going to have a chance to check this out for a while (2
    weeks holidays in about 6 hours from now), but I'm sorta interested in
    the roof idea.
    
    						-Ian

    
    
    	If the exposed ductwork is inaccessible to you to wrap it with more
    	insulation to prevent condensation, perhaps you may be able to use a
    	long thin piece of wood or something similar to push more insulation 
    	over it to keep it warmer and avoid the condensation.  
    
    	I had a similar problem with my ductwork in the attic, and what
    	I did was to put a piece of tape over the extractor switch in the
    	bathroom in the winter time, so that no-one will turn it on by
    	accident.  I just don't use it in the Winter time, that way the
    	heat and humidity stay in the house and this helps to keep the
    	house warm and comfortable.  When the warm weather arrives, I
    	remove the tape off from the switch, and use the extractor again,
    	and during that time of the year there is no problem with 
    	condensation because the attic is always warmer, and this is the
    	time of the year when you want to remove the heat from the bathroom.
             

re: .47

It collects in a bend, where it's never been enough to cause a problem 
(knock on wood).  And, in the spirit of .48, we don't run the fan that long.
The winter goal is most definitely to keep the mirror clear while we're in the
bathroom, rather than the summer goal of removing as much humidity as possible.

   Gary

    In the winter, my family is trained to leave the bathroom door open
    when taking a shower (unless prudish relatives are visiting...).  The
    cats like that, and it takes some of the load off the humidifier and
    benefits the African violet population.
    
    In the summer we use the vent fan, to take some of the load off the
    dehumidifier.

I'm going to install a ceiling fan in my bathroom.  I have some questions about
it (especially *after* reading all these replies and other notes).

I've seen a lot of notes talking about rigid duct materials such as aluminum,
PVC etc. and at the same time discounting the flexible plastic type ducts.  So
much that it makes me wonder if the flexible plastic type ductwork does really
work in many cases?  Does it?  In my attic, I have a straight run from the vent
to a soffit (see figure).  There are no bends (except down to the soffit), it's
a short run (3-6 feet), and it'll be well covered with insulation.  The
flexible plastic type should work, right?

                                   \
                                    \
           +---+___________________  \
___________|___|=================. \ |
           |fan|              |  | | |
           -----              |__|_|_|
                              | 
                              | 
                                 

I also am looking for input on the best place to put the fan.  (A, B or C?)


           ----------------LL--m--i--r--r--o--r-LL-
           |  |toilet|    |  (sink)       counter |           
 exterior  :w --------     -----------------------             
   wall    :i  /   \                             entrance door 
     |     :n |     |     +A+           +C+                   
     |     :d  \___/                                          
     \---> |o                    _________________|           
           |w--------------------|       |                    
           | /-----------------\ | linen |                    
           ||          shower/ +=| closet|                    
           ||      +B+  bath   +=|       |        LL = light (hanging)
           | \_________________/ |       |
           |---------------------|-------|


My wife said she wouldn't mind  a light over the shower (for shaving) since the
shower curtain blocks the light.  I could get a unit with a light if I were to
put it there (B). I don't recall ever seeing one directly over the shower so I
wondered if there was a reason. Would it cool the shower too much if it were on
while in the shower?  Would it be better to be near the mirror, to help defog
that quicker (A or C)

Can anyone think of a reason why any of the three locations noted would be
better than the other?


I picked up a 70 CFM  (65 sq ft) Broan unit at Somerville Lumber (which, BTW, I
may have to exchange if I decide to go with the light).  I read the
installation directions but it mentioned nothing about sealing the crack
between the fan housing and the cut in the sheeetrock.  Should I cover this
crack to prevent excess moisture from getting into the attic.  Or will the
moisture through here be minimal?  

I assume I can I put insulation on top of the fan?

Also, the unit I bought had the fan motor *below* the plastic "turbine" where
it is exposed to all the moist air that is passing through it.  Is this a good
design or should the motor be protected from moisture?

Thanks.

I'd pick location A, as B might make the shower uncomfortable.

You might consider using flexible aluminum duct rather than the plastic/wire
stuff.

The gap between the sheetrock and the unit is usually covered by a bezel
supplied with the fan.

In general, you should not insulate over or within three inches (I think)
of the fan unit; check the instructions for details.

I wouldn't worry too much about the motor.

			Steve

Go with location A.

	This will get rid of other odor's besides the moisture better.

If you want a light in the shower, get a separate unit, the look better than
the light/fan combo's.  I am also not sure if the fan/light combo's are
'suitable for damp location'.

Use flexible aluminum for the hose.  
	It has the advantages of plastic (flexible) and also has less
resistance (the folds are smaller) so your fan more the air more efficiently.

Brian

    I think anywhere along the line between A and C would be fine
    depending upon how your switches are set up.  In some set ups,
    the fan, the fan light, and the lights "LL" are all on separate
    switches.  If the fan light becomes the main/most commonly used,
    then it should be positioned in the center of the room.
    
    -al

    When I installed the fan in my 1/2 bathroom, I put it directly over the
    shower stall.   I didn't have much choice about it, since the center of
    the room was already occupied by a heat/light combination unit.
    
    It's worked fine, and does a nice job of venting the steam staight out
    of this (quite small) room.  My feeling is that if you are concerned
    about moisture, puttn the fan as close a possible to the source will
    work best.
    
    	Andrew
    

re: .53

We got a round combination light/fan unit with a wood-look trim ring that's
actually quite nice, and saved us the trouble of mounting two units.  I agree
that the typical rectangular combination units are pretty ugly.

   Gary

    I'm in the process of installing a bathroom ceiling fan.  The plan is to 
    go with an in-wall timer (hard wired, in place of a switch).  A couple
    minor questions come up:
    
     1.  Anyone know if timers and covers come in WHITE, and where to
         find in the Eastern Mass area? (Not the usual ivory/beige or 
         silver/black combination).  I've called a few Elec. Supply 
         places with no luck.
    
         If not made, how about a WHITE cover with the hole (eg. dimmer
         cover) and a WHITE knob?  I know it will not have the timer
         numbering. 
    
    2.   I've heard the spring timers are noisy.  Is this so?  Are
         there other timer types that are not?
     
    
    Thanks for your time(r)!
    
    
    

    Intermatic makes one that allows you to use an existing plate and gives
    you a small insert for the numbers. The insert and knob is ivory
    though. It is the wind up type. I don't mind the noise but my wife
    hates it.

    maybe they come in white too?

Does the timer make so much noise that it is noticeable over the noise of the
fan? 

    
    I was going to ask the same thing. I can't beleive you would hear these
    timers over the bathroom fan. In my case we are using it for a flood
    light. The old one was noisy and bothered my wife. The new one (that uses
    existing plate) makes very liitle noise and looks nice. And my wife is
    happy.
    

    This seemed like the best note to ask this:
    
    I too unfortunately have the "window-in-the-bath/shower" as others lately
    have been talking about asking for shower curtains for it in a
    different note...
    
    Anyway I'd like to install a bathroom fan rather unconventially.  My
    idea is as follows.  I'd like to install a fan vertically (problem #1 -
    finding a bathroom vent fan that _can_ be mounted vertically) and I'd
    like to install it in the wall opposite the window.  I intend to mount
    it high on that wall and run the vent tubing straight down inside the wall 
    to vent out a wall-mounted louver in the wall outside the bathroom at a
    lower spot, maybe a foot or so from the floor.
    
    The kicker is I need a reversible fan.  My idea is in the summer to
    draw cool air from floor level just outside of the bathroom, up the
    vent tubing, and the fan would blow this cool air high and vent the 
    hot/moist air out the open window.  In the winter I'd flip the reverse
    switch, keep the window shut (of course) and vent the hot/moist air
    from the ceiling, down the vent tubing, and out the lower mounted vent
    outside the bathroom to provide heat and humidity in the winter months
    to inside the house.  I also intend to mount a timer if it can be had for 
    the right price in addition to the reversible switch.
                                    
    Sound feasable?  I just need a shallow mounting, vertically mountable
    reversable bathroom fan.  Seems the best way to utilize the unwanted
    window in the bathroom....
    
    Steve

    Does anybody have any recommendations on bathroom fans for inside the
    bathtub?  We just installed a skylight(right outside the tub), so I'd
    like for the fan to be plenty strong.  Currently, the hole for the
    light(only a light) inside the tub is ~ 5-6" diameter.  Are there fans
    small enough to fit, yet strong enough to suck out the hottest
    showers????  Cutting a bigger hole(it's tiled) could present problems
    that I'd like to avoid if possible.
    
    Certain people in the family, which will remain nameless, like to take
    LOOOONG HOOOOOT showers that steam up the room big time.
    
    thank you
    
    regds
    	John

To revive an old note:

We've finally decided to install a fan in our bathroom after 10
years of steam and iced windows in the winter.  Because the 
bathroom is a dormer on the back of the house, we can't install
a ceiling fan without venting through the roof -- something
I don't want to do, no matter how "weather-tight" the 
electrician assures me it will be.

Our only other alternative is to put a wall fan on the outside 
wall.  My question is this:

Do wall fans work as well as ceiling fans in venting bathroom
moisture?  Should they be as high up on the wall as possible 
or does it matter? 

The least offensive looking wall fan is a NuTone ceiling/wall fan
that is rated at 80 CFM and a duct size of 3".

Is that big enough to clear the moisture
out of a 6 X 9 foot bathroom?  The catalog says it's for 
"bathrooms of 75 sq. feet or less", but I just want to make 
sure that the wall fan would do a pretty good job before I spend
the money for the installation.

Thanks a lot for any answers!

Diana

The wall fan will work fine.  The idea is to draw the moist air out of the
room which will be replaced by drier air from elsewhere in the house.  
It's probably best to have it reasonably high on the wall, as the warmer,
moister air will collect up there, but it's not critical.  A wall fan
with a duct of 3" should be fine.  Make sure that the outside "hood" seals
tight - you may want to consider one of those clothes dryer vent hoods
with the floating plastic "shuttle" - they're about $20 at many hardware
stores and in catalogs (eg. Brookstone).

				Steve

re: .57

What makes you think it's easier to get a weather-tight
wall vent than roof vent?  We've done both (roof vent for 
bathroom, wall vent for dryer) with equal success.  It doesn't
require a great deal of skill to spread roofing tar.

   Gary

Re: .59

Because the wall vent would be sheltered by an overhang from 
above and won't have rain, snow, etc. falling directly on it.  
The roof vent would be totally exposed to the elements. 

They make roof vents specifically designed for this purpose.  I have one
on my roof, which is much "flatter" than most roofs (it's the back of a
full-dormered Cape).  I've yet to have a problem with "the elements".  It
even has a screen to keep out the birdies.

				Steve

    
    .....you can always open the top and bottom of the window
    or open the door after your done.....
    
    $0. fix!  :)

    
    One the two I installed, the damper is part of the fan housing.
    These are in the ceiling.
    
    Fred
    

I've got a similar situation.  There is no fan in our 1/2 bath off the
main bedroom, and mold tends to run amok at times.  However, from veiwing
things in the attic, it appears that there is a PVC pipe that runs
to where the light in the shower stall is, that connects up to the roof
vent.  There is a fan in the full bath, and that seems to vent to the
same pipe, but now, after reading the various notes here, I'm not so sure.
The pipes do eventually vent up through the roof.  Assuming I'm not totally
off here, I was planning on replacing the light fixture in the 1/2 bath
with a light/fan combo, which would be in the shower stall.  But now I'm
wondering if the pipes I'm seeing are really part of the plumbing stack,
and if I might run into problems should I proceed with my plan.  Is there 
any distinct way of telling?  The full bath fan must vent somewhere, and
those pipes seem to be the only logical possibility.  I'll be checking
out light/fan combo's today, but I think I should go back and inspect 
things a bit closer before I commit myself.  Any thoughts here?

Thanks,
PeterT

That PVC pipe is part of the waste plumbing of the house - don't connect your
fan to it.  If someone else did this, they were, if you'll excuse me, an
idiot, and a code inspector would be very upset.

It's really quite simple to install a roof vent hood and run ducting to
a fan.

				Steve

> That PVC pipe is part of the waste plumbing of the house - don't connect your
> fan to it.  If someone else did this, they were, if you'll excuse me, an
> idiot, and a code inspector would be very upset.

I'm not totally sure this is the case, but I wouldn't put it past the 
contractor.  As I say, I'll have to take a closer look before I do anything.

Thanks,
PeterT

>That PVC pipe is part of the waste plumbing of the house - don't connect 
>your fan to it.  If someone else did this, they were, if you'll excuse me, 
>an idiot, and a code inspector would be very upset.
 
In other words, the s**t would hit the fan?

Clay

More likely is that you'd get methane gas vented into your bathroom if there
was any sort of "pull".

			Steve

    
    If you are installing an exhaust fan primarily to remove the
    totally saturated air (visible humidity), the process is slow.
    Without getting into how much moisture is being exhausted vs.
    being mixed with "house air" which is carrying moisture and
    when is this air being made up from that your throwing out
    via the fan, - after exiting the tub, turn the shower nozzle
    to the back side of the enclosure and turn on the cold water.
    You'd be amazed at how fast the RH will disappear.  
    
    In controlling areas where low RH is needed, we take the cold
    condensate that comes off air conditioning coils and spray it
    right back into the air before the coils.  This condensate is
    way below the dew point temperature and moisture collects
    moisture.  Much like your toilet on certain days when the 
    make up water is below the dew point in your house.
    
    It takes awhile for the moisture on the mirrors to disappear
    for it has to re-evaporate.  It down take a lot of cold water
    running either. Just a couple of minutes. Do it as soon as you
    step out and you'll find that the mirrors don't fog up.
    
    Fred
    
                                                                    

    
    
    ......Fred,  I just about have the "wet the shower curtain"
    trick established.  No you expect me to teach the "run the
    cold water after showering" trick!!!! :):)
     ...but it does work..
    JD

Well, I took a look last night and found the main bathroom fan is not venting
into the plumbing stack,  just into the attic.  No problems noticed there
with extra moisture (if'n you don't count the times when the roof was 
leaking ;-).  Our bathroom is rather small, but I'll check out the cold
water trick.  We're more concerned with the extra moisture providing a
good medium for mold to grow, rather than the mirror fogging up.  The mold 
grows almost exclusively on the wallboard area above the fiberglass shower
enclosure.

Thanks,
PeterT

Venting directly into the attic is generally a bad idea.

		Steve

     I think its always a bad idea. An attic is one place where moisture
    can cause LOTS of problems.
    
    				Kenny

    
    
    ....Good place to grow mushroom with the added moisture and
    summer heat!!!:)
    
    It will also lower your R-value....
    
    JD

    
    	I just installed a wall mount vent for our 1st floor bathroom
    	vent fan.  When the house was built (2 years ago) they didn't
    	do this.  So, as part of finishing the upstairs I did it.  The
    	hose runs below the 2nd floor bathroom, and once I do the floor,
    	I won't be able to get to the hose.  
    
    	My concern is bug type critters entering from the outside vent,
    	and building homes in there.  The wall vent has 5 or 6 flaps
    	that open when the fan runs, then gravity close.  How can I
    	install some sort of screen near the outside to discourage
    	critter contractors, without putting one on the outside and 
    	having it look bad?  I though about putting a screen in from
    	the 1st floor bath side, but that leaves the entire hose for
    	population.
    
    	thanks, Glenn.....
    

Re: .75

Use a different sort of vent, such as the one I described earlier that
has a plastic "shuttle" that rises up when the fan is on and falls down to
seal the opening when off.  These are generally sold for clothes dryers,
though - I'm not certain how they'll work on an exhaust fan.  But the
vent you have is also meant for dryers.

				Steve

    
    	.76
    
    	Steve, I'm a bit confused (nothing new).  You say plastic
    	"shuttle".  Do you mean the one that looks like a round 'flap'?
    	It would be hinged at the top, and the fan pressure would blow
    	it out and open, then when the fan is off, it falls back into
    	place.  I have another vent that was given to me, and is sort
    	of like that, but it doesn't seem to close tightly.  It looks
    	sort of like this, from a side view:
    
    			|\
                 -------+ \
    			A  \
                 -------+   \
    			|____\
    		
    	Where 'A' is a round flap hinged at the top.   "UUUGGGGLLLYYYY"
    
    	The one I have is flatter, sticks out from the sheathing about 1".
    
                         +-+
    	                 | \
    		---------+ \
                           \
                ---------+ \
                         | \
                         +-+
    
    	Still ugly, but not as bad.  It seems to seal pretty good, but
    	when a bug wants in, it comes in.  Mostly concerned with bees,
    	hornets, etc.  
    
    	Of course, I could always turn it into entertainment, by once a
    	year, firing up the fan, spraying wasp and hornet spray into the
    	fan inlet, and seeing what comes staggering out the exhaust 8*)))))
    
    	thanks, Glenn....
    

No, it's not either of those.  But if you think the first one you described
is ugly, you won't like the one I'm thinking of.  However, neither of the
kind you picture seal tightly, though the first one can do a better job
than the second (though few do.)

The exhaust air comes out through a 90-degree elbow which points up.  On
top of this elbow is a larger "cap" which is open at the bottom.  Inside the
cap, a smaller plastic cap can slide up and down; in the down position it
seals the elbow.  When air comes out, it pushes the cap up and the air flows
around and out through the bottom of the bigger cap.  It typically sells
for about $20.  I bought one for my clothes dryer; haven't installed it yet.

				Steve

    
    
    	Oh, OK, haven't seen one of those.  I think what I will do is
    	next spring, look to see if I can remove some of the vanes and
    	put a piece of screen behind them to cover the round opening.
    
    	thanks for the help, Glenn.....
    

    I don't recommend that, as it will quickly clog up with lint, etc.
    
    			Steve

    
    Steve - where can I get the shuttle type? I've seen them on houses and
    I know they seal much better that the 'flap' type, but I haven't seen
    them in stores.
    
    				Kenny

I bought mine at Hammar Hardware in Nashua.  I've also seen it in various
mail-order catalogs including Brookstone (I don't think they carry it at the
stores.)

				Steve

  I've been real tempted to go for one of these as the washer/dryer's in a
bathroom and the floor is real cold in the winter. Every couple of months I'm
out at the flapper pulling away a bunch of lint that's keeping it from closing
well. I've only seen the shuttle types in magazine ads and was concerned about
how difficult it might be to clean the lint out of then when they (inevitably,
at my house anyway) get lint in them.

						Trace

    
      I'm not positive, but I think the only place for the lint to catch is
    on the outside on the cage that holds the shuttle. That would be the
    easiest to clean.
    
    					Kenny

The top of the outer cap lifts off and you can pull out the shuttle and clean
to your heart's content.  But yes, there's really not much of a place for
lint to collect.

					Steve

    
       <<< Note 1138.80 by TLE::LIONEL "Free advice is worth every cent">>>
    
>        I don't recommend that, as it will quickly clog up with lint, etc.
>
>                            Steve
    
    	Are you talking as a dryer vent only?  Or also for the bathroom
    	vent.  Remember, the appl. here is for the bathroom vent fan.  I
    	do agree about that in the case of the dryer vent....
    
    	thanks, Glen(n)
    

You'll get lint even with a bathroom fan - I have one of those small
"ceramic heaters"  I use in the bathroom and its filter needs regular
cleaning - I would hesitate on putting any kind of fine mesh (fine enough to
keep bugs out) on a small exhaust vent, no matter where the air came from.

				Steve

Re: Bathroom lint..........

Look at the input screens for your (or your SOs) hair drier........


                        C L O G G E D  !

- jw

Re: Bathroom lint..........

Yes, bathroom fans do collect and output lint AND THEN the warm moist 
air hits the lint and encourages mold and mildew to grow which further 
clogs any fine mesh screens. 

FWIW I did see at HQ recent a preformed screen that would go over the
standard vent and one for the new low profile vents. These screens use
1/4" mesh though and would NOT be any good for stopping bugs, only
birds and small critters. 

Your best bet would to stick with either of the standard types and try 
to install them carefully so that they don't twist or warp and not 
seal properly. You can also check them first to see that the parts 
move freely and do not bind.

Charly

    
    	When in doubt, do nothing.....
    
    	I was in the yard Sat. cleaning up, and looked at the louvers,
    	and they seem to seal better than I thought.
    
    	So, I decided that the best course of action would be to.....
    	Relax, don't worry, have a homebrew  8*)))))
    
    	I'll keep an eye on things in the spring, and hope that the bugs
    	don't find the space attractive.  My biggest concern is that once
    	the 2nd floor bath floor is down, I won't have a way to get to
    	the duct connecting the vent/fan in the 1st floor bath to the
    	outside vent....  But, I do have long arms.
    
    	thanks for all the help....
    
    	Glen(n)
    

    Bathroom steam/mold etc. seems to be a more common problem than I
    thought it would be.
    
    I have a pretty small bathroom and the steem is taking it's toll. Black
    mold is growing in various places on the ceiling and around the shower.
    Also around the window. Corners of the wallpaper are beginning to curl.
    
    I know the answer is to install an exhaust fan (and want to) but I have
    the same problem others have elluded to. I have a one bath ranch and
    the bathroom is smack in the middle of the house. Running an exhaust
    hose to the soffet in either direction is a 20 plus foot run. Also, 
    being a ranch, the eve is level with the "ceiling" so going out the eve
    is not only REAL difficult to get to but the exhaust would be pointing
    down which creates other problems.
    
    When I was looking around a couple of months ago anticipating buying a
    fan, I "swear" I saw two different kinds. One that required ducting and
    one that "didn't". The one that didn't was about $50 bucks as I recall.
    When I went back to the hardware store a couple of weeks ago, they only
    had the ducted type. I asked them about it and they didn't seem to know
    what I was talking about. In fact they SAID they didn't know what I
    was talking about.
    
    Now I'm intrigued by the reply in .45 which talks about a recirculating
    fan with a carbon filter and requires no duct work. Does this really
    do the job of getting rid of the steam and preventing the mold etc.
    and is it a realistic replacement for an exhaust fan when steam is the
    problem.

Yes, they exist.  No, they won't help you.

		Steve

    
 >   Running an exhaust hose to the soffet in either direction is a 20 plus
 >   foot run. Also,  being a ranch, the eve is level with the "ceiling" so
 >   going out the eve
    
    Why can't you go up & out through a roof vent?

    
      If you have moisture in the air, you must send the air outside -
    replacing it with less humid air, or you must have some other way to
    take the water out of the air. No amount of 'circulating' will remove
    the excess humidity in your bathroom from the air. You have two
    choices, you can go out the soffet or gable end of the house, or out
    through the roof. It is EXTREMELY bad for your house if you vent the
    humid air into the attic space.
    
    					Kenny

    
    
    Hummmmmm.....  Seem to me if its that much of a problem to
    go up and out.  Why dont you just go out.  Install a fan
    in the wall.  Something like what would be in a kitchen.....
    
    Worst case would be to open the top of the window.  Put one of thoes
    fans that the frame extends to close up the open part and
    turn it on?????
    
    JD

re .95:

If you reread the original note, you'll see that there's no outside wall
anywhere near the bathroom.

Hmmm.  Would that go through the roof idea work?  I know you can't just stick
a pipe straight up like the vent stack, because unlike the vent stack which
is connected to a waste line, there'd be  no place for rain water to go 
except into the fan.  But could you get one straight up with a hat on it?
I'd think that in New England you'd be setting up a tremendous source of
cold air infiltration but most of those bath fans come with a cheap little
flapper door to prevent back drafts.  It just might work, wouldn't it?

Question for base noter.  Is the attic all unfinished?  Is it a hipped roof
or are there gable ends someone so you could run your piping across the
attic floor and out an end wall?

I ran 18' through PVC and get a terrific flow, much better than shorter
runs through that flexible dryer vent trash they sell with the fans which
I suspect seriously restricts air flow with all the drag induced.

I've also gone short runs through a ceiling to a soffit and came straight
down through the eave which is the application the base noter described and
gotten sufficient flow.  I found I was most successful when I used 4" pvc,
the stuff they sell for drainage, not the more expensive schedule 40.

>Hmmm.  Would that go through the roof idea work?  I know you can't just stick
>a pipe straight up like the vent stack, because unlike the vent stack which
>is connected to a waste line, there'd be  no place for rain water to go 
>except into the fan.  But could you get one straight up with a hat on it?


	Bathroom fans are vented through the roof all the time. They have
	clappers or dampers as well as caps, to keep out the weather and to
	insulate (an un-capped vent would just pour cold air into your
	house!).

	Roy

    Thanks for all the hints and suggestions. I suppose there's nothing
    wrong with going straight up and out. Probably undue fear on my part.
    It's just that the roof is 20+ years old and I didn't want to temp
    fate.
    
    Apparently people have been successful running long lines. I had made
    the assumption that 20+ feet of hose/pipe would be too high a volume
    of air for a bathroom fan to push effectively. Maybe not.

    I'm hearing a very loud "whirring" noise from my 1/2 bath light/fan
    (sort of sounds like the ball bearings in the fan are shot) - the light
    is working just fine.
    
    The questions I have are:
    
    	o  is it worth getting the fan unit repaired or should I just
    		buy a new one (new ones are about $25-$30 at Home Depot)
    
    	o  who would I call to get this replaced or even looked at to
    		identify the problem (plumber, electrician, handyman,
    		etc.???)  Any recommendations in the Lowell/Chelmsford
    		area?
    
    Thanks!
    	
    							-Sujal-

I just fixed a fan that exhibited the same symptom last week...


just pulled down the plastic face, exposing the fan motor.
squirted a few drops of oil on the shaft at different points.

works like a charm now.

When that happened to my attic fan, it was because the set screw that
holds the fan blades to the motor shaft had come loose. The motor shaft
was spinning inside the fan blade.

Art

    The fan motor should be removable without taking the whole thing
    down.  Take off the cover, and you should see some nuts or screws
    that hold the fan and motor in place.  The cord for the fan will
    probably have a plug on it so you can just unplug it and take it
    out.  (If you're unlucky, the cord will go into an electrical 
    junction box and you'll have to undo the connectors; if so, turn
    off the apprporiate circuit breaker first!!!)
    
    Then proceed to oil as in .1 to see if that will fix it.
    
    If it doesn't fix it, I think I'd be inclined to try to find a new
    motor rather than replace the whole unit, even if the final cost is 
    about the same.  Getting the old unit out is likely to be quite a pain.

Two years later...and another bath fan problem.

I have a basement bathroom with a small window but no fan. There are signs of
bad mildew/mold (we just moved in) and I'd like to sacrifice at least part of
the window to run a fan duct out.

Questions:

Does anyone know who might fabricate a window for me with space for a duct to
run out? I'd do it myself, but I want the window to open and I don't have the
skills/tools to make an opening window frame. 

I can either run a wall fan directly out the window, or try to install a fan
over the shower itself. I prefer the latter, but the problem here is that the
duct has to run across the first floor joists. I don't have space to run it
under the joists, and I suspect there's no practical way to run it through them.
Can anyone verify/debunk this? 

Thanks,

John

    	If you are sure that your joists are running the wrong way, you may
    be able to just put one directly through the wall with a self-closing 
    louvered vent. Is the problem that you have to go through concrete and
    that's why you want to use the window ?
    
    	Ray

>Is the problem that you have to go through concrete and that's why you want to
>use the window ?

Yes. There's an added complication of a soffit above the window, so I may just
have to stick with a wall fan sent through the window. Thanks.

    It might be easier and cheaper to go thru the concrete rather than
    having custom window work done.  I used a rental tool to drill a
    neat 4" diameter hole thru 10" concrete.  Cost was around $50-60
    and it took an hour or so.  --  Vince
    

Most glass shops can cut a hole for a vent in a window - fairly cheaply, too.

				Steve

    	I'd think it would be hard to get anything professional looking by
    putting something in the window like that. If looks aren't much of an
    issue, I believe I saw something at Home Depot designed to mount a 4"
    flexable dryer hose to a small basement-type window.
    
    	If you have (or go with) a dropped ceiling, you could install a
    traditional fan/light in the ceiling and run the hose out the window
    with the vent kit. You'd just have to cut a round hole througha ceiling
    tile near the window. Other than that, the drill mentioned earlier
    seems like the way to go.
    
    	Ray

As far as the hole in the wall goes, the entire window is below grade. It opens
into a well, which is just wide enough for the window.

I've decided to put off part of the problem by taking the window out, building a
frame divided in two, and installing a wall fan in one part. I'll just stick a
piece of plywood in the other side for now, until I can find someone to make me a
window. Or graduate to making one myself.

Thanks for the suggestions.

John

    I have a 2-story plus a full attic house. I would like to install a
    fan/light combo in the bathrooms in each floor. The second floor
    bathroom is easy cause I have access to the full attic. I can open a
    hole thru the ceiling and run an exhaust pipe (4inch diag) to the
    outside wall. I'm concern about the first floor bathroom. I'll have to run
    the exhaust in-between the first floor ceiling and the second floor's
    subfloor parallel to the floor joist to the outside wall. According to
    the building book I have, there are two types of framing :
    
    1. traditional - the floor joist sits on top of the plate, and the end
    of the joist is butted against the band (?). The band is the same hight
    as the joist but nailed perpendicula to the end of the joist. I believe
    it is the band that I need to open a 4inch hole to let the exhaust pipe
    out. Am I right ? It doesn't look like this band (?) is a load bearing
    structure so cutting a hole will not affect the structure of the house,
    am I right ?
    
    1. balloon - the ourside stud goes from the sil/plate on the foundation
    wall all the way to the top of the second floor ceiling. Each of the
    floor joist on the second floor is support by a 1x4 wood (forgot what it 
    is called) which is nailed at the inside edge of two adjacent studs.
    Then, there is another piece of wood nailed onto the joist and the
    adjacent stud to act as firestop. There is some space between the bottom
    of this firestop wood and the top of the 1x4 wood that supports the joist.
    But I don't think it is large enough to let the 4" pipe to go thru. If
    I have to make a 4" hole, do I make the hole on this firestop wood ? If
    not, is there any other way ?
    
    Thanks.
    

Re: .107

	you could also mount the fan in the outside wall of the bath
	and vent it right through the wall.

    re: 108
    
    No, that wouldn't work. The bathtub is at the outside wall. Unless I
    make a box to box up the fan and the duct. That wouldn't look good.
    

>     No, that wouldn't work. The bathtub is at the outside wall. Unless I
>     make a box to box up the fan and the duct. That wouldn't look good.

	It would work, but obviously it's your choice as to wether
	a wall mount (vs. ceiling) looks good.

	I don't understand why you would have to box up the fan and the duct??

	The fan *and* the duct when mounted in the wall and vented through
	the wall (ie. directly outside) are all hidden inside the wall.
	All you'll see is the same thing you'll see in a ceiling installation,
	ie. the grill.

	They sell bathroom fans designed specifically for this purpose
	so that they will fix in a 2x4 outside wall.  If you do go
	this route, and mount the fan where it is in arms reach from
	inside the tub, then you need to make sure you purchase a fan
	that specicially states it supports such an installation, and
	you must make sure its on a leg of an electrical circuit protected
	by a ground fault interruptor (GFCI).

	The only thing I didn't like about a wall installation is that
	since the moist steam rises, the fan may not be able to suck
	out all the air if it's not mounted very high up on the wall.

    I recently extended my deck and now have an occasional problem of odors
    from the bathroom trap vent. It happens when there's a slight or no
    wind. It wasn't a problem before because the deck wasn't near the vent. 
    It's just not enjoyable to sit out there when this happens. Can I
    solve this problem by extending the vent past the peak? Maybe I'll just
    get a fan out there. 
    
    Any suggestions?
    
    Paul