Hello,

I live in Maryland. My bathroom is located on a second story, with one
side to the outside, and 2 of the other sides to insulated, though
unfinished/unheated attics. The ceiling also abuts an attic and the
side with the door faces a finished but unheated hallway...

We just redid the bathroom with all new paint, hardware, fixtures,
lighting, the whole deal. We installed a small but powerful exhaust
fan. I am unsure of the brand but it is a popular model. The actually
fan is several yards from the intake, thus it is noise free. It is very
powerful and has a user changeable timer to keep it running after you
turn off the light switch that it uses.

As you can figure, the bathroom gets very cold in the mornings, there
is one register under the cabinet, but do to known issues in the house
with heating capacity, it cannot compete with the cold spaces around
it. When I shower in the mornings, the walls and glass mirror are very
cold, and thus water vapor condense on everything. There is a built-in
space heater on the wall that I turn on which keeps the glass from
fogging--but the the walls continue to accumulate moisture which tends
to bead up and run down them.

Is there anyway to have the fan not suck up all of the heat as well as
steam? This room is already showing signs of water damage to the walls
and its not ever 6 months old. I think that I need more ventilation but
I want it to be above 65 degrees all of the time. What can I do?

"Elliott Plack" writes:

Hello,

I live in Maryland. My bathroom is located on a second story, with one
side to the outside, and 2 of the other sides to insulated, though
unfinished/unheated attics. The ceiling also abuts an attic and the
side with the door faces a finished but unheated hallway...

We just redid the bathroom with all new paint, hardware, fixtures,
lighting, the whole deal. We installed a small but powerful exhaust
fan. I am unsure of the brand but it is a popular model. The actually
fan is several yards from the intake, thus it is noise free. It is very
powerful and has a user changeable timer to keep it running after you
turn off the light switch that it uses.

As you can figure, the bathroom gets very cold in the mornings, there
is one register under the cabinet, but do to known issues in the house
with heating capacity, it cannot compete with the cold spaces around
it. When I shower in the mornings, the walls and glass mirror are very
cold, and thus water vapor condense on everything. There is a built-in
space heater on the wall that I turn on which keeps the glass from
fogging--but the the walls continue to accumulate moisture which tends
to bead up and run down them.

It doesn't sound the fan is really doing its job for some reason if
moisture is running down the walls.

I'd also check to see if there's a leak in teh ducting between the fan
and the bathroom itself. With the fan remote like that, I THINK but
I'm not certain that its air moving efficiency suffers somewhat.

I noted a marked difference when I replaced an aging exhaust fan that
I thought was doing a good job -- my bathroom with the shower is small
and with teh door closed, the mirror doesn't even fog up anymore, as a
datapoint. We're in Chicago, and there's no space heater in this
bathroom. But granted, only the ceiling is to the attic and has R-40
over it, and I leave the door open to it all night so the wall
surfaces aren't that cold in the morning.

A few questions--do you keep the bathroom door closed at night? If
so, consider leaving it open so the walls can at least get some heat
so they aren't so cold in the morning. If not, also that one vent
doesn't have a chance to heat the room as there's probably no cold air
return and the room just kinda pressurizes.

Another thing to check is the below door gap -- is there any way for
dry air to get into the room when the van is exhausting? If not,
you'll burn your fan out by making it try to pull a vacuum in the
room, and the moisture won't go anywhere.

Finally what is the duration of the showering/bathing in that room?
Excessively long?


--
Todd H.
http://www.toddh.net/

Maybe light up a cigarette or incense and see what the fan actually does to
the smoke as a test of the air moving capability. Also, perhaps use a
register fan to pull more heat into the bathroom overnight. Todd's thoughts
of leaving the door open and ensuring the below door gap are good too.
Tomes

"Elliott Plack" wrote in message
ups.com...
Hello,

I live in Maryland. My bathroom is located on a second story, with one
side to the outside, and 2 of the other sides to insulated, though
unfinished/unheated attics. The ceiling also abuts an attic and the
side with the door faces a finished but unheated hallway...

We just redid the bathroom with all new paint, hardware, fixtures,
lighting, the whole deal. We installed a small but powerful exhaust
fan. I am unsure of the brand but it is a popular model. The actually
fan is several yards from the intake, thus it is noise free. It is very
powerful and has a user changeable timer to keep it running after you
turn off the light switch that it uses.

As you can figure, the bathroom gets very cold in the mornings, there
is one register under the cabinet, but do to known issues in the house
with heating capacity, it cannot compete with the cold spaces around
it. When I shower in the mornings, the walls and glass mirror are very
cold, and thus water vapor condense on everything. There is a built-in
space heater on the wall that I turn on which keeps the glass from
fogging--but the the walls continue to accumulate moisture which tends
to bead up and run down them.

Is there anyway to have the fan not suck up all of the heat as well as
steam? This room is already showing signs of water damage to the walls
and its not ever 6 months old. I think that I need more ventilation but
I want it to be above 65 degrees all of the time. What can I do?

Elliott,
Focus on the surfaces that border on unconditioned space - walls,
ceilings. Seal air leaks that allow cold air to move through insulation
and into wall & floor cavities.

You should have a blower-door test done on your home to find any
unintended air leaks, seal them, and then add more insulation as
needed.

Walls that border on attic space are often not airtight. I'll bet that
you just have fiberglass batts placed between the wall studs (assuming
you have insulation on these walls!). Keep in mind that fiberglass
insulation can't stop cold air from moving through - it must be in an
enclosed, airtight box to be effective.

If you can't find a technician to do a blower-door test you can check
some things yourself. Go into the side attics and look behind the
insulation. If you find any openings where you can see into the floor
cavity (usually adjacent to the tub/shower) these must be sealed with a
rigid material so no cold air can enter. If you have fiberglass
insulation make sure it is cut to fit around protrusions and cabinets
through the walls. It has to lay flat against the heated surface
without gaps and voids. Finally, install rigid backing on the studs to
create the airtight box. Foam board insulation works well and 1 inch
will add another R-5.

Don't forget about the floor cavities. Unless they are blocked off at
the attic cold air will move under the bathroom floor. If the side
attics have floor boards you might need to pull some boards to check.

Meanwhile, use your space heater and the bath fan. Moisture is the
number one enemy of your home.

By the way, sounds like you have a great ventilation system. Please use
it! The heat-loss penalty is very small, but excessive moisture
condensing on and inside your walls can lead to big problems.