On Wed, 6 Apr 2011 11:37:36 -0700 (PDT), DerbyDad03
wrote:

On Apr 6, 11:51*am, mike wrote:
On Apr 6, 7:02*am, N8N wrote:





Was it ever acceptable by code to vent a bathroom fan to an attic? *I
was helping my cousin over the weekend with some minor renovations to
her condo - she wanted to replace the fan in one of the bathrooms, and
when I went up into the attic to unhook it I found that both it and
the one in the master bathroom were not vented to the outside, but had
a maybe 4' piece of dryer duct just tied to the trusses and venting
into the attic.

Originally I thought that this might have been a shortcut taken by the
roofers that replaced her roof just before she moved in, but either
they replaced none of the sheathing or all of it as it all looked
consistent. *Also I took a look at other similar units as I was
walking down the street and I didn't see any vent caps in the likely
locations on any of the roofs.

The way she explained it to me was that anything done to the outside
of any of the condos was taken care of by the association, not her
(e.g. roofs, siding etc.) so knowing exactly who to yell at would be
important.

Worst case, I guess, would be that this was a shortcut taken by the
original builder some 15-20 years ago, and it's not going to be
fixed...

nate

You can reduce the risk of problems if you just run the fan when it's
warmer outside. * When you start to see your breath outside in colder
weather, you can leave the fan off, and rely on forced air heating (if
you have it) to dehumidify the bathroom and humidify the rest of the
house which probably needs the humidity in colder weather anyway.

So, one could take a shower in the morning as the furnace is running
continuously.- Hide quoted text -

- Show quoted text -

I'm not seeing the advantage of not using the exhaust fan during the
heating season.

Hot air rises, taking the humidity with it, thus the reason the fans
are placed on the ceiling.

Forced air returns are normally placed near the floor to help
circulate the air, and if I'm not mistaken, you don't use cold air
returns in a bathroom due to various odors that might be circulated
throughout the house.

So, what you are suggesting would require that the returns in the
other rooms would need to pull the humidity from the upper portion of
the bathroom, which would require that all doors remain open for this
to even be possible. Even with the doors open, it's going to take a
lot of suction to exhaust the bathroom ceiling area with returns in
other rooms.

The humidity will disperse throughout the house whether there are
vents or suction or not. It's airborne and the humidity is higher
in the bathroom but eventually it will reach equilibrium.

That doesn't even discuss the problems with the moisture condensing on

If there are such problems. Not everyone has them, especially in
houses with low humidity, especially in the winter when indoor
humidity is lower, especially if there is no humidifier. And a
little condensation does no damage. It evaporates again when the
bathrooom humidity is lower, an dit gets lower when the humidity in
the bathroom leaves through the bathroom door.

The OP needs to evaluate his particular situation.


the walls and ceilings of the bathrooms before the returns in the
other rooms have had a chance to remove it.

Besides, why do you say the furnace is running "continuously" in the
morning? That would depend on how much heat was needed bring the house
up to temp, even after a substantial set-back.

Timing a family full of showers with the heating cycle in the hope
that the cold air returns will circulate the moisture throughout the
house seems like a heat or miss attempt, even if every door was left
open.