humidity control using bathroom fan

[hotrod53]

I have had this question on my mind for a while....my bathroom fan had a humidistat to control humidity. Is it recommended or safe to let this run when the home is unoccupied for weeks at a time? Would it do me any good? My home is in the mountains and humidity/dampness is an issue, the windows are closed and the blinds are partially drawn, is this the way to prevent it? I am currently running a dehumidifier all summer.

[Mark]

An a/c or dehumidifier is the best way to remove humidity.

Guess I've never heard of a humidistat on a bathroom fan. Definitely not an idea that has caught on! Personally I'd bypass the humidstat and use the fan when you shower & such. I don't think your gaining much in the effort to reduce humidity with the fan running all the time except in super high humidity levels, like when you shower.

Mark

[hotrod53]

If it's not something that people are responding to, you might be right....it didn't catch on. I took the fan apart a few years ago and disconnected that part of it. Actually my fan was noisy and I took it apart to clean and lube it when I got zapped with 120V, that is how I figured out that it was fed two ways, switched and no switch. I actually disconnected it because I was afraid to let it run for weeks at a time with no one there.

[Yanita]

Hi,

JMO here, but in your first post you said moisture/humidity is a problem in your area.

Do you have a moisture barrier under your home...in other words do you have a 6 mil ply plastic sheeting covering the ground from corner to corner, side to side of your home?

There are many threads on this if you care to do a search.

Just a thought,

Yanita

[Kellguy]

Humidistats are now common in many stick-built homes, as are controllers on plenums which force fresh air into the home. The humidistat is commonly found in a hallway and it activates a bathroom fan.

In winter, there are very specific limits of humidity levels which are intended to prevent mould build-up and window condensation, both of which are primary products of high humidity.

In older mobile, high humidity is common due to the tight design (metal roofs and walls).

I would NOT disconnect the fan/humidistat, but I would also not leave it running for an extended period of time. Leave a few windows open about a 1/16 of an inch. Humidity levels will reduce dramatically when you are not there anyway.

[hotrod53]

Yanita, you are exactly correct, I need to put my vapor barrier down. I currently do not have one other than the belly insulation.

[Yanita]

Hi Hotrod,

Also make sure that your vents are open during the year, closed in the winter.

Do not allow weeds and bushes to obstruct the air flow .

Yanita