Hi,
The basement of our homeowner association community house is unfinished and has a dirt floor. We've already put down continuous heavy plastic, but the humidity is still significant and anything we store down there made of wood (or paper) grows mold. We don't have financial ability to properly waterproof, pour concrete slab, etc. for another couple of years. I was thinking of installing a vent fan in one of the several open crawlspace vents to suck air out of the basement, acknowledging there may be rainy days where it might be more humid outside than inside. My concern is outdoor temperature. We're in New York State. I don't want to create a negative pressure and draw cold air in if the outdoor temp is less than, say, 40F as it would risk freezing pipes elsewhere in the basement. Can anyone recommend a vent fan controller that would turn off at a low temp? I only see vent controllers that turn on/off at higher temps... like in an attic.
Many thanks
Theodore

On Sunday, September 10, 2017 at 11:56:40 PM UTC-4, wrote:
Hi,
The basement of our homeowner association community house is unfinished and has a dirt floor. We've already put down continuous heavy plastic, but the humidity is still significant and anything we store down there made of wood (or paper) grows mold. We don't have financial ability to properly waterproof, pour concrete slab, etc. for another couple of years. I was thinking of installing a vent fan in one of the several open crawlspace vents to suck air out of the basement, acknowledging there may be rainy days where it might be more humid outside than inside. My concern is outdoor temperature. We're in New York State. I don't want to create a negative pressure and draw cold air in if the outdoor temp is less than, say, 40F as it would risk freezing pipes elsewhere in the basement. Can anyone recommend a vent fan controller that would turn off at a low temp? I only see vent controllers that turn on/off at higher temps... like in an attic.
Many thanks
Theodore

An AC line thermostat used for electric resistance heating? IDK how low
they go, but probably to at least 45 which would be low enough. I'd
probably put it on a timer too. How well it will work, IDK. I'd be
concerned about when there is a rapid temp change, it's cool inside
and you pump humid outside air in. It's more days than just rainy
conditions. I guess the fan will also equalize the temp, so maybe
it will work OK. I'd proceed cautiously if there is stuff stored down
there that belongs to other people, etc. If it gets wrecked after
you install the fan, they may come after the condo association.
No condo reserves to pay for fixing it right now, raising the fees a bit
to pay it back to the reserves?

Right... that's the other concern: drawing in 90F humid air in July when it's a cool 75F in the basement will cause even more condensation. So I'd have to have a sensor that measures/accounts for relative humidity too!? Maybe getting complicated. But, all opinions greatly appreciated.

On Monday, September 11, 2017 at 10:29:49 AM UTC-4, wrote:
Right... that's the other concern: drawing in 90F humid air in July when it's a cool 75F in the basement will cause even more condensation. So I'd have to have a sensor that measures/accounts for relative humidity too!? Maybe getting complicated. But, all opinions greatly appreciated.

You could wire in a humidistat in series too that would respond to
outside humidity. I could rig up something for my own house fairly
easy. For a condo, you'd probably need an electrician.

If you want to respond to both outside humidity and temperature,
I'd go with a relay system. Plug the fan into a receptacle controlled
by a relay, use low voltage to control the relay. For a relay,
google "relay in a box". Then you just need low voltage temp
and humidity sensors, one that will close when temp is above
a set point, the other that will close when humidity is below
a set point and a 24V transformer.

posted for all of us...



Hi,
The basement of our homeowner association community house is unfinished and has a dirt floor. We've already put down continuous heavy plastic, but the humidity is still significant and anything we store down there made of wood (or paper) grows mold. We don't have financial ability to properly waterproof, pour concrete slab, etc. for another couple of years. I was thinking of installing a vent fan in one of the several open crawlspace vents to
suck air out of the basement, acknowledging there may be rainy days where it might be more humid outside than inside. My concern is outdoor temperature. We're in New York State. I don't want to create a negative pressure and draw cold air in if the outdoor temp is less than, say, 40F as it would risk freezing pipes elsewhere in the basement. Can anyone recommend a vent fan controller that would turn off at a low temp? I only see vent controllers
that turn on/off at higher temps... like in an attic.
Many thanks
Theodore

I'm more concerned the association doesn't have enough money. What happens
when an emergency occurs? What & where is this?

--
Tekkie