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  #1   Report Post  
Jim
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

All,


I need a little advice from those that have installed bathroom exhaust
fans and the proper way to vent them. I am in the process of
deciding if I should just vent the fan into the attic or cut a
hole/holes in the soffit and have the ducting terminate at this
opening. One other option is to install a pvc T fitting in an
existing plumbing vent and have it vent through the roof. Is the last
method acceptable in most areas as far as the building codes?


If I drill 6 or 7 1/2 inch holes in a 4'' diameter circle through
the aluminum soffit and tape the end of the fan duct to the soffit at
this location, will thismethod be sufficient to vent the fan? The
problem I have is that the roof line is about 35-40 feet high so the
only way I can access the soffits is through the attic.

thanks
  #2   Report Post  
Wayne Whitney
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

On 2005-11-11, Jim wrote:

I am in the process of deciding if I should just vent the fan into
the attic or cut a hole/holes in the soffit and have the ducting
terminate at this opening. One other option is to install a pvc T
fitting in an existing plumbing vent and have it vent through the
roof. Is the last method acceptable in most areas as far as the
building codes?


None of these methods is really acceptable. Venting into the attic is
right out, you need to remove the moisture from the house. I'm sure
venting into a plumbing vent is forbidden, you could conceivably get
sewer gases coming out the fan vent. Venting through the soffit is
allowed, but it is not really a good idea, because some of the
moisture will migrate back upwards, condense on the soffit, etc.

The two good options are (1) vent through the roof and (2) vent
through the sidewall, at least 3' below the soffit and at least 4'
horizontally from any operable windows.

Cheers, Wayne

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Todd H.
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

Jim writes:

All,


I need a little advice from those that have installed bathroom exhaust
fans and the proper way to vent them. I am in the process of
deciding if I should just vent the fan into the attic


No no no!

Unless you like mold having a nice damp place to call home in your
attic.

I had two of these corrected on my current home when I
purchased it. They are now properly vented with roof caps. The
soffit thing might work too.

--
Todd H.
http://www.toddh.net/
  #4   Report Post  
Jim
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

On Fri, 11 Nov 2005 13:43:54 -0600, Wayne Whitney
wrote:

On 2005-11-11, Jim wrote:

I am in the process of deciding if I should just vent the fan into
the attic or cut a hole/holes in the soffit and have the ducting
terminate at this opening. One other option is to install a pvc T
fitting in an existing plumbing vent and have it vent through the
roof. Is the last method acceptable in most areas as far as the
building codes?


None of these methods is really acceptable. Venting into the attic is
right out, you need to remove the moisture from the house. I'm sure
venting into a plumbing vent is forbidden, you could conceivably get
sewer gases coming out the fan vent. Venting through the soffit is
allowed, but it is not really a good idea, because some of the
moisture will migrate back upwards, condense on the soffit, etc.

The two good options are (1) vent through the roof and (2) vent
through the sidewall, at least 3' below the soffit and at least 4'
horizontally from any operable windows.

Cheers, Wayne


I suspected that these would be better solutions, however, they are
both problematic in my case. The sidewall is made of brick and I do
not want to punch ar hole in my roof unless it is absolutely
necessary for obvious reasons. I really do not want another 4 inch pvc
pipe sticking out of my roof. The bathroom is on hte front side of the
house.
  #5   Report Post  
Wayne Whitney
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

On 2005-11-11, Jim wrote:

I do not want to punch ar hole in my roof unless it is absolutely
necessary for obvious reasons. I really do not want another 4 inch
pvc pipe sticking out of my roof.


The usual roof termination for a bathroom exhaust fan is quite short,
it's not an exposed pipe. An exposed pipe would allow rain into the
vent, a bad idea. [Doesn't matter for the sewer, though!] See, for
example http://www.broan.com/display/router.asp?ProductID=2925.

Cheers Wayne



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Jim
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

On Fri, 11 Nov 2005 14:33:24 -0600, Wayne Whitney
wrote:

On 2005-11-11, Jim wrote:

I do not want to punch ar hole in my roof unless it is absolutely
necessary for obvious reasons. I really do not want another 4 inch
pvc pipe sticking out of my roof.


The usual roof termination for a bathroom exhaust fan is quite short,
it's not an exposed pipe. An exposed pipe would allow rain into the
vent, a bad idea. [Doesn't matter for the sewer, though!] See, for
example http://www.broan.com/display/router.asp?ProductID=2925.

Cheers Wayne


Thanks. I didn't realize that these were available.
  #8   Report Post  
BP
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

What everyone else said.
Plus: you run the flexible duct into the soffit. Flexible vinyl duct is much
better to use for ease of installation in this instance. (Does not apply to
dryer venting.) Use a powerful drill with a 4-1/4" hole saw to drill a
perfectly round hole into the soffit. It is best to use a "hole-hog" with an
offset clutch for this job. A regular drill can pull you right off a ladder
if the hole saw binds up in the hole which is very likely with a 4" hole
saw. You must cut the hole from outside. You should hire a
carpenter/handyman to do this if you are not comfortable on a ladder that
high. You pull the flex duct out of the hole while out on the ladder. You
then use a standard 4" round aluminum soffit vent to tape to the flex duct
after stretching it over the inner ring. Push the flex duct back into the
hole until the round vent is flush and secure with a couple of brass brads.
Usually best to drill a couple of tiny holes for the brads while on the
ground. Easy as pie.
Alternative: Use a roof vent. Requires you to get up on the roof and do some
shingle re-work. I hate these. They are an eyesore and are an invitation to
leaking, especially in cold climates.

"Jim" wrote in message
...
All,


I need a little advice from those that have installed bathroom exhaust
fans and the proper way to vent them. I am in the process of
deciding if I should just vent the fan into the attic or cut a
hole/holes in the soffit and have the ducting terminate at this
opening. One other option is to install a pvc T fitting in an
existing plumbing vent and have it vent through the roof. Is the last
method acceptable in most areas as far as the building codes?


If I drill 6 or 7 1/2 inch holes in a 4'' diameter circle through
the aluminum soffit and tape the end of the fan duct to the soffit at
this location, will thismethod be sufficient to vent the fan? The
problem I have is that the roof line is about 35-40 feet high so the
only way I can access the soffits is through the attic.

thanks



  #9   Report Post  
Todd H.
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

Jim writes:
I forgot to mention that the attic is well ventilated just with the
existing soffits and ridge vent. Everytime I go up there, I can feel a
slight breeze. I've always been puzzled as to how this would cause a
moisture problem in the attic. After all during a rainstorm, the air
that gets pushed through the soffits is loaded with humidity. I'm sure
it's at least 90%.


Regardless of the attic breeze or no, you don't want to vent into the
attic--if for no other reason that most home inspectors will flag it
in a heartbeat, regardless of how much ventilation. A roof cap is the
way to go.

--
Todd H.
http://www.toddh.net/
  #10   Report Post  
BobK207
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

Jim-

Where is the house?

In my previous SoCal home both batroom fans had their flex aluminum
ducts terminate near / against the gable end attic vent

I never had any mositure problems but SoCal is near desert conditions.


If you're in an area where condensation could occur make sure you do it
right. You will be buying a lot more trouble downstream

The "correct way" is a roof penetration. The soffit solution is ok as
well, as long as the flow terminates with an acceptable "vent cover".

cheers
Bob



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Joseph Meehan
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

Jim wrote:
All,


I need a little advice from those that have installed bathroom exhaust
fans and the proper way to vent them. I am in the process of
deciding if I should just vent the fan into the attic or cut a
hole/holes in the soffit and have the ducting terminate at this
opening. One other option is to install a pvc T fitting in an
existing plumbing vent and have it vent through the roof. Is the last
method acceptable in most areas as far as the building codes?


If I drill 6 or 7 1/2 inch holes in a 4'' diameter circle through
the aluminum soffit and tape the end of the fan duct to the soffit at
this location, will thismethod be sufficient to vent the fan? The
problem I have is that the roof line is about 35-40 feet high so the
only way I can access the soffits is through the attic.

thanks


As indicated by others, non of the above.

Through the sidewall or the roof. A poor third would be through the
soffit, which may not be code locally.

--
Joseph Meehan

Dia duit


  #12   Report Post  
wkearney99
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...


I forgot to mention that the attic is well ventilated just with the
existing soffits and ridge vent. Everytime I go up there, I can feel a
slight breeze.


Well then, if there's enough room up there, then how about just routing the
exit duct out the rear roof instead of on the front? You want 'as little
ducting as necessary' though. Otherwise there are plenty of low-profile
roof vents than can either be found in closely matchig color to your
existing roofing material, or painted to blend in.

  #13   Report Post  
Mikepier
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

I'll probably get yelled at for this, but I just put in a bathroom vent
fan, and in my attic I have 2 roof vents plus an electric whole house
attic fan that vents through the top (about 18" in diameter). Rather
than cut another hole in my roof, I ran rigid 4" duct from the
bathroom fan to just under where the attic fan is ( about 8 feet total
duct). So far its working great. I know this is still not the right
way, but at least I routed the vent close to where the opening in the
roof is. Some people just let the fan vent in the attic, and letting it
gradually find its way to the vent in the roof.

  #14   Report Post  
M.Burns
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

One thing I'm starting to learn the hard way (now that my wife is selling
real estate) more buyers are requesting home inspections ...and some
communities are requiring it ...before they buy. Inspectors are finding
things the current occupants have juryrigged. Sometimes if the list is long
enough, it kills the deal. Other times the seller has to have the stuff
corrected. I'm lucky I haven't done a lot of these kinds of things (but
have done a few) but it sure opened my eyes. I'm tending to do things the
right way lately. Just a caution.


"Mikepier" wrote in message
oups.com...
I'll probably get yelled at for this, but I just put in a bathroom vent
fan, and in my attic I have 2 roof vents plus an electric whole house
attic fan that vents through the top (about 18" in diameter). Rather
than cut another hole in my roof, I ran rigid 4" duct from the
bathroom fan to just under where the attic fan is ( about 8 feet total
duct). So far its working great. I know this is still not the right
way, but at least I routed the vent close to where the opening in the
roof is. Some people just let the fan vent in the attic, and letting it
gradually find its way to the vent in the roof.



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Jim
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

On 11 Nov 2005 15:24:40 -0800, "BobK207" wrote:

Jim-

Where is the house?

In my previous SoCal home both batroom fans had their flex aluminum
ducts terminate near / against the gable end attic vent

I never had any mositure problems but SoCal is near desert conditions.


If you're in an area where condensation could occur make sure you do it
right. You will be buying a lot more trouble downstream

The "correct way" is a roof penetration. The soffit solution is ok as
well, as long as the flow terminates with an acceptable "vent cover".

cheers
Bob


The house is in Virginia. The winters are relatively mild. Certainly
nothing like Minnesota or New England. Temps rarely stay below
freezing. The end of the flexible aluminum duct was just laid on top
of the soffit.

What I will probably end up doing is to extend the ducting upward
until it is within a few feet of the ridge vent. There's just me
living in the house and I rarely take long, hot showers.

Also, how critical is it that the fan be installed level and plumb
for proper operation? I installed it a bit out of level.



  #16   Report Post  
Posted to alt.building.construction,alt.home.repair
gary
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

Use insulate flex ducting to prevent moisture condensation and put a U in it
so that any water that might get in the pipe through the top of the vent
does not drain back into your fan.


"BP" wrote in message
et...
What everyone else said.
Plus: you run the flexible duct into the soffit. Flexible vinyl duct is
much better to use for ease of installation in this instance. (Does not
apply to dryer venting.) Use a powerful drill with a 4-1/4" hole saw to
drill a perfectly round hole into the soffit. It is best to use a
"hole-hog" with an offset clutch for this job. A regular drill can pull
you right off a ladder if the hole saw binds up in the hole which is very
likely with a 4" hole saw. You must cut the hole from outside. You should
hire a carpenter/handyman to do this if you are not comfortable on a
ladder that high. You pull the flex duct out of the hole while out on the
ladder. You then use a standard 4" round aluminum soffit vent to tape to
the flex duct after stretching it over the inner ring. Push the flex duct
back into the hole until the round vent is flush and secure with a couple
of brass brads. Usually best to drill a couple of tiny holes for the brads
while on the ground. Easy as pie.
Alternative: Use a roof vent. Requires you to get up on the roof and do
some shingle re-work. I hate these. They are an eyesore and are an
invitation to leaking, especially in cold climates.

"Jim" wrote in message
...
All,


I need a little advice from those that have installed bathroom exhaust
fans and the proper way to vent them. I am in the process of
deciding if I should just vent the fan into the attic or cut a
hole/holes in the soffit and have the ducting terminate at this
opening. One other option is to install a pvc T fitting in an
existing plumbing vent and have it vent through the roof. Is the last
method acceptable in most areas as far as the building codes?


If I drill 6 or 7 1/2 inch holes in a 4'' diameter circle through
the aluminum soffit and tape the end of the fan duct to the soffit at
this location, will thismethod be sufficient to vent the fan? The
problem I have is that the roof line is about 35-40 feet high so the
only way I can access the soffits is through the attic.

thanks





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Mikepier
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

Flex ducting in addition to putting a U in the ducts puts more
resistance on the flow being discharged from the fan which impedes its
performance. In addition, any "trapped" water in that U would also put
resistance on the flow.Putting in rigid duct with minimum bends would
decrease the chances of the ducts sweating since it will exhaust
better. In my opinion, if you leave the fan on for even 5 minutes after
a shower it would be enough time for the fan to clear the bathroom of
humid air and by the time the fan is turned off, the likely hood of
moisture in the duct will have greatly decreased.

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Mikepier
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...


Jim wrote:
Also, how critical is it that the fan be installed level and plumb

for proper operation? I installed it a bit out of level.


The instruction manual on the Broan vent fan I put in says put on a
ceiling with no more than a 12/12 pitch. I am not sure what that means,
maybe 12" of pitch for every 12 feet?
Maybe someone else knows. I think its for proper operation of the
damper.

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Goedjn
 
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Jim wrote:
Also, how critical is it that the fan be installed level and plumb

for proper operation? I installed it a bit out of level.


The instruction manual on the Broan vent fan I put in says put on a
ceiling with no more than a 12/12 pitch. I am not sure what that means,
maybe 12" of pitch for every 12 feet?
Maybe someone else knows. I think its for proper operation of the
damper.



Same units for rise as run, either 12"/12" or 12'/12'.
NOT 12"/12'.

45 degrees. 100% grade, Pii/4 radians from horizontal.
  #20   Report Post  
Posted to alt.home.repair
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

"I'll probably get yelled at for this, but I just put in a bathroom
vent
fan, and in my attic I have 2 roof vents plus an electric whole house
attic fan that vents through the top (about 18" in diameter). Rather
than cut another hole in my roof, I ran rigid 4" duct from the
bathroom fan to just under where the attic fan is ( about 8 feet total
duct). So far its working great."

One problem with this is that the attic fan is now likely drawing out
air from your bathroom even when the bathroom fan is off. In summer, I
would think a good deal of airconditioned air would go out this way.



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Default Installing a bathroom exhaust fan and the proper way to vent it...

" Through the sidewall or the roof. A poor third would be through the
soffit, which may not be code locally. "

I don't know where venting a bathroom fan out the soffit is a code
violation? Here in NJ most homes are done that way and we are about as
regulated as it gets. I don't see anything wrong with doing a soffit
vent.

  #23   Report Post  
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Default Installing a bathroom exhaust fan and the proper way to vent it...

"What happens is that warm moist air is drawn into the next soffit vent

into the attic space where it can cause damage. Remember that soffit
vents
are normally air inlets. "

I guess that's theoretically possible, but has anyone ever seen it lead
to an actual problem? Bathroom fans are almost always on for a short
time, so any moisture that was introduced should dissipate pretty
quickly. I have a hard time believing that in actual practice, this
is really an issue. It's done on most of the homes here in NJ that
I've seen and hasn't been harmful.

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BP
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...


wrote in message
oups.com...
"What happens is that warm moist air is drawn into the next soffit vent

into the attic space where it can cause damage. Remember that soffit
vents
are normally air inlets. "

I guess that's theoretically possible, but has anyone ever seen it lead
to an actual problem? Bathroom fans are almost always on for a short
time, so any moisture that was introduced should dissipate pretty
quickly. I have a hard time believing that in actual practice, this
is really an issue. It's done on most of the homes here in NJ that
I've seen and hasn't been harmful.


Many people in these groups state their personal opinions in absolutes.
Grain of salt.


  #25   Report Post  
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Chas Hurst
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...


wrote in message
oups.com...
"What happens is that warm moist air is drawn into the next soffit vent

into the attic space where it can cause damage. Remember that soffit
vents
are normally air inlets. "

I guess that's theoretically possible, but has anyone ever seen it lead
to an actual problem? Bathroom fans are almost always on for a short
time, so any moisture that was introduced should dissipate pretty
quickly. I have a hard time believing that in actual practice, this
is really an issue. It's done on most of the homes here in NJ that
I've seen and hasn't been harmful.


I've got the fan vented thru the soffit. In cold weather the vented air
condenses quickly making it visible. It's quite obvious that it blows away
from the house and does not get sucked back into the adjoining vent.




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BP
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...


"Joseph Meehan" wrote in message
...
wrote:
"What happens is that warm moist air is drawn into the next soffit
vent

into the attic space where it can cause damage. Remember that soffit
vents
are normally air inlets. "

I guess that's theoretically possible, but has anyone ever seen it
lead to an actual problem? Bathroom fans are almost always on for a
short time, so any moisture that was introduced should dissipate
pretty quickly. I have a hard time believing that in actual
practice, this is really an issue. It's done on most of the homes
here in NJ that I've seen and hasn't been harmful.


The point is why do it that way when there are better ways?

I don't know if there are documented problems when it is properly
vented out the soffit, but it is common that someone will just put the
vent close to a soffit vent and consider that proper venting. That has
been reported as causing problems.

I have heard of a couple of cases where someone reported that even when
properly venting out through the soffit there has been problems, but I am
slightly skeptical of those so I would not say it has been documented. .


You are probably referring to the ventilation of combustion appliances in
which case you have a valid point. But unless you are dealing with someone
with extraordinary toxic farts the problem with a bath fan vent is not a
issue worth worrying about. You are making a mountain out of a molehill.


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Vince
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

On Thu, 17 Nov 2005 17:22:15 GMT, "Joseph Meehan"
wrote:

wrote:
" Through the sidewall or the roof. A poor third would be through the
soffit, which may not be code locally. "

I don't know where venting a bathroom fan out the soffit is a code
violation? Here in NJ most homes are done that way and we are about
as regulated as it gets. I don't see anything wrong with doing a
soffit vent.


What happens is that warm moist air is drawn into the next soffit vent
into the attic space where it can cause damage. Remember that soffit vents
are normally air inlets.



When we had siding done a few years ago, I was not sure where a
future exhaust fan would be mounted within the bathroom. An exhaust
vent (a BuildersEdge product, special ordered from Home Depot) was
installed in the soffit at that time. The vent, which has no moving
parts, was centered within the span of the existing bathroom window;
that bothered me for the reasons that you mentioned, Joe.

Recently had a contractor gut and redo our bathroom including the
addition of a Panasonic FV-08VQL3 fan. He strongly urged me not to go
through the roofline, (apparently because he was not a roofer). As it
turned out, the fan was mounted within the wet area, which made it NOT
inline with the existing vent. After some discussion about
positioning of the flexible duct (I objected to having any bends in
the layout of the duct), the existing vent was simply relocated such
that there is a short and straight run of approximately four feet to
the (relocated) vent in the soffit.

Going through the roof would have been agreeable with me. Not enough
thickness to mount this fan within the vertical wall. The use of
soffit vents is commonly used. The damper is within the fan assembly
itself, not in the exhaust vent that is mounted at the soffit.

I have not been up on a ladder to test the air flow yet; but am hoping
that the duct tape does not dry out and fall apart ...

FWIW.

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yourname
 
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Default Installing a bathroom exhaust fan and the proper way to ventit...

I have a hard time believing that in actual practice, this
is really an issue. It's done on most of the homes here in NJ that
I've seen and hasn't been harmful.



I've got the fan vented thru the soffit. In cold weather the vented air
condenses quickly making it visible. It's quite obvious that it blows away
from the house and does not get sucked back into the adjoining vent.




Ya know, last year I put two vents in through the roof. They don't cost
much, don't take long and don't leak. It's just a bad ida to vent them
in the attic period
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Beer Guess
 
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Is this DIY job, or better for a contractor's?

Did you do it youself?

I have the same problem with my 5 year old house. I don't know how
building inspector approved it!


yourname wrote:
I have a hard time believing that in actual practice, this

is really an issue. It's done on most of the homes here in NJ that
I've seen and hasn't been harmful.




I've got the fan vented thru the soffit. In cold weather the vented air
condenses quickly making it visible. It's quite obvious that it blows
away
from the house and does not get sucked back into the adjoining vent.




Ya know, last year I put two vents in through the roof. They don't cost
much, don't take long and don't leak. It's just a bad ida to vent them
in the attic period



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Chas Hurst
 
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"yourname" wrote in message
news:2l7ff.13164$Rb.2712@trndny04...
I have a hard time believing that in actual practice, this
is really an issue. It's done on most of the homes here in NJ that
I've seen and hasn't been harmful.



I've got the fan vented thru the soffit. In cold weather the vented air
condenses quickly making it visible. It's quite obvious that it blows

away
from the house and does not get sucked back into the adjoining vent.




Ya know, last year I put two vents in through the roof. They don't cost
much, don't take long and don't leak. It's just a bad ida to vent them
in the attic period


So you put 2 holes in your roof and I didn't. Furthermore I vented out thru
the soffit not in the attic. I hope your holes in the roof turn out better
than your reading comprehension.


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yourname
 
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Chas Hurst wrote:
"yourname" wrote in message
news:2l7ff.13164$Rb.2712@trndny04...

I have a hard time believing that in actual practice, this

is really an issue. It's done on most of the homes here in NJ that
I've seen and hasn't been harmful.


I've got the fan vented thru the soffit. In cold weather the vented air
condenses quickly making it visible. It's quite obvious that it blows


away

from the house and does not get sucked back into the adjoining vent.




Ya know, last year I put two vents in through the roof. They don't cost
much, don't take long and don't leak. It's just a bad ida to vent them
in the attic period



So you put 2 holes in your roof and I didn't. Furthermore I vented out thru
the soffit not in the attic. I hope your holes in the roof turn out better
than your reading comprehension.


And thus my house is up to code and yours isn't. there is no difference
between a vented soffit and the attic. I am happy that your insulation
isn't soaking wet, but you won't be working on my house anytime soon.
Hey, the gas furnace usually vents away from the house too, but you
don't put it right next to the window.

Since I merely pointed out that it was not a big deal to put it through
the roof, the same way that the soil stack does for the very same
bathroom, an is not prone to leaks, I think it is your reading
comprehension that is questionable.
  #33   Report Post  
Posted to alt.building.construction,alt.home.repair
Chas Hurst
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...


"yourname" wrote in message news:0R8ff.68$N44.6@trndny08...
Chas Hurst wrote:
"yourname" wrote in message
news:2l7ff.13164$Rb.2712@trndny04...

I have a hard time believing that in actual practice, this

is really an issue. It's done on most of the homes here in NJ that
I've seen and hasn't been harmful.


I've got the fan vented thru the soffit. In cold weather the vented air
condenses quickly making it visible. It's quite obvious that it blows


away

from the house and does not get sucked back into the adjoining vent.




Ya know, last year I put two vents in through the roof. They don't cost
much, don't take long and don't leak. It's just a bad ida to vent them
in the attic period



So you put 2 holes in your roof and I didn't. Furthermore I vented out

thru
the soffit not in the attic. I hope your holes in the roof turn out

better
than your reading comprehension.


And thus my house is up to code and yours isn't. there is no difference
between a vented soffit and the attic. I am happy that your insulation
isn't soaking wet, but you won't be working on my house anytime soon.
Hey, the gas furnace usually vents away from the house too, but you
don't put it right next to the window.

Since I merely pointed out that it was not a big deal to put it through
the roof, the same way that the soil stack does for the very same
bathroom, an is not prone to leaks, I think it is your reading
comprehension that is questionable.


Maybe a hole in your roof isn't a big deal. It is in mine. And you're
absolutely correct that I won't be working on your house. I don't do
business with assholes.


  #34   Report Post  
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Joseph Meehan
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

BP wrote:
"Joseph Meehan" wrote in message
...
wrote:
"What happens is that warm moist air is drawn into the next soffit
vent

into the attic space where it can cause damage. Remember that
soffit vents
are normally air inlets. "

I guess that's theoretically possible, but has anyone ever seen it
lead to an actual problem? Bathroom fans are almost always on for a
short time, so any moisture that was introduced should dissipate
pretty quickly. I have a hard time believing that in actual
practice, this is really an issue. It's done on most of the homes
here in NJ that I've seen and hasn't been harmful.


The point is why do it that way when there are better ways?

I don't know if there are documented problems when it is properly
vented out the soffit, but it is common that someone will just put
the vent close to a soffit vent and consider that proper venting. That
has been reported as causing problems.

I have heard of a couple of cases where someone reported that
even when properly venting out through the soffit there has been
problems, but I am slightly skeptical of those so I would not say it
has been documented. .


You are probably referring to the ventilation of combustion
appliances in which case you have a valid point. But unless you are
dealing with someone with extraordinary toxic farts the problem with
a bath fan vent is not a issue worth worrying about. You are making a
mountain out of a molehill.


There does seem to be differing opinions on the subject. While I am
inclined to believe that it is not a big problem, I would not want mine
vented that way.

--
Joseph Meehan

Dia duit


  #35   Report Post  
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Dennis
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

Your kidding right? Trap the duct?

"gary" wrote in message
newslRef.522479$tl2.34263@pd7tw3no...
Use insulate flex ducting to prevent moisture condensation and put a U in
it so that any water that might get in the pipe through the top of the
vent does not drain back into your fan.





  #36   Report Post  
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gary
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

That is done on all new buildings here. I just took a picture of one today.
Can I upload binaries here? Do you really think a slight U in a 4" pipe is
going to fill up with water from the minimal amount of snow or rain that
might get into the pipe? If you get that much water in there the trap is
NOT your problem. You have other problems. If you do not put the "trap"
there where do you think that water goes. Right into your fan, your motor
and your grill (if metal) and causes rust.


"Dennis" wrote in message
newsP9ff.22603$5R4.2331@trnddc06...
Your kidding right? Trap the duct?

"gary" wrote in message
newslRef.522479$tl2.34263@pd7tw3no...
Use insulate flex ducting to prevent moisture condensation and put a U in
it so that any water that might get in the pipe through the top of the
vent does not drain back into your fan.





  #37   Report Post  
Posted to alt.building.construction,alt.home.repair
gary
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

That is not done here and I believe it is against code. The moisture in the
winter builds up ice and causes problems in the soffit and with any wood in
there.


wrote in message
oups.com...
" Through the sidewall or the roof. A poor third would be through the
soffit, which may not be code locally. "

I don't know where venting a bathroom fan out the soffit is a code
violation? Here in NJ most homes are done that way and we are about as
regulated as it gets. I don't see anything wrong with doing a soffit
vent.



  #38   Report Post  
Posted to alt.building.construction,alt.home.repair
Chris Lewis
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

According to BP :
"Joseph Meehan" wrote in message
...


I have heard of a couple of cases where someone reported that even when
properly venting out through the soffit there has been problems, but I am
slightly skeptical of those so I would not say it has been documented. .


You are probably referring to the ventilation of combustion appliances in
which case you have a valid point. But unless you are dealing with someone
with extraordinary toxic farts the problem with a bath fan vent is not a
issue worth worrying about. You are making a mountain out of a molehill.


I seem to recall, either in Fine Homebuilding or a CMHC publication that
under certain circumstances in cold climates venting up through the roof
can lead to thermosyphoning hot air continuously when the fan is off. Which
wastes heat, and in a properly vented "cold" attic, can lead to condensation
problems inside the vent line, resulting in water dripping from the fan and
corrosion. In a previous home, we had exactly that problem on really cold
days - sitting on the throne getting dripped on from above (no comments
about below ;-)

In those cases, venting out horizontally through the wall, or down through
the soffit was superior, because it won't thermosyphon.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.
  #39   Report Post  
Posted to alt.building.construction,alt.home.repair
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...

"I seem to recall, either in Fine Homebuilding or a CMHC publication
that
under certain circumstances in cold climates venting up through the
roof
can lead to thermosyphoning hot air continuously when the fan is off.
"

Veeery interesting! I had never thought about that. I suspected a
similar and worse effect occurs when people run a bath vent to the
underside of a roof mounted fan. When the roof fan runs in summer, it
will suck cool airconditioned air from the bathroom, even if the
bathroom fan is off. I would think as you pointed out, that just
having a straight up run from the bathroom to a regular roof vent would
provide and ideal path for convection.

  #40   Report Post  
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BP
 
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Default Installing a bathroom exhaust fan and the proper way to vent it...


"yourname" wrote in message
news:2l7ff.13164$Rb.2712@trndny04...
I have a hard time believing that in actual practice, this
is really an issue. It's done on most of the homes here in NJ that
I've seen and hasn't been harmful.



I've got the fan vented thru the soffit. In cold weather the vented air
condenses quickly making it visible. It's quite obvious that it blows
away
from the house and does not get sucked back into the adjoining vent.




Ya know, last year I put two vents in through the roof. They don't cost
much, don't take long and don't leak. It's just a bad ida to vent them in
the attic period


Only you are talking about venting into the attic. No one else. Try to keep
up.


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