How to wire crawl space exhaust fan, fresh air fan with a dehumidistat
#1
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How to wire crawl space exhaust fan, fresh air fan with a dehumidistat
Hey there, I have a crawl space in an apartment building that has a fan to bring in fresh air in and a damper/actuator with an end switch controlled by a dehumidistat when the humidity gets past a certain percent. I'm just not 100 percent sure how to wire it all to work. Any help would be great!
Thanks
Thanks
#2
We need a lot more information: what wires do you have on each device? what voltages are each device? do you already have a circuit or does a new one need to be installed? can you post some pictures?
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Sorry. It's all 120v. So apparently how it's suppose to work is once the humidistat is over whatever it is set for it would open a damper/w the actuator with an end switch and then that would turn on the fan to bring fresh air in.
#4
As previously posted by ben:
http://www.doityourself.com/forum/li...rt-images.html
what wires do you have on each device... can you post some pictures??
#7
Anyone please?
#12
I'm not so sure about using a humidistat to bring in "fresh air". How do you know the air coming in is lower in humidity then what's already in the crawl space ? It could be raining outside and bringing that air in would increase the humidity. The humidistat would keep cycling as the damp air came in.
Here's the basic wiring I think you'd follow...
Here's the basic wiring I think you'd follow...

#14
Ok.... and how do you plan on running the wires. I have drawn you an operating diagram that I think will work for you as we haven't been given any particulars on the louvers and end switch set up.
Yes...you need a two wire feed from the panel. Where are you bringing power to ?
Describe in words what you want to do.
I would take a two wire cable from panel to humidistat. Then a two wire from humidistat to louver/damper combo. Take a two wire from the louver to the fan. All that would be two wire cable with ground. There are several way of wiring it using less wire with three wire cable but slightly more confusing.
Same drawing.... just spread out. Also added mandatory service switch at fan location.
Yes...you need a two wire feed from the panel. Where are you bringing power to ?
Describe in words what you want to do.
I would take a two wire cable from panel to humidistat. Then a two wire from humidistat to louver/damper combo. Take a two wire from the louver to the fan. All that would be two wire cable with ground. There are several way of wiring it using less wire with three wire cable but slightly more confusing.
Same drawing.... just spread out. Also added mandatory service switch at fan location.

Last edited by PJmax; 05-01-16 at 10:23 AM.