So if your fan is rated at 1500 cfm you will need about two feet of totally open space in your attic.
How to tell if my attic fan is on.
Likewise adjustable thermostats will shut the fan off.
You simply add up the nfas of all your vents and divide that number by the area of the attic to determine whether you re within the 1 150 ratio.
This is done because you need one square foot of ventilation area for every 750 cfm that your fan can push.
Now take that number and divide it by 750.
When the temperature within the attic reaches a set point the fan will turn on and start venting the heated air cooling the attic space.
How to tell if you need an attic or whole house fan.
Turn the attic fan off and unplug the motor from the thermostat.
If the fan turns on the motor is still good.
Step 1 test the fan motor.
The warm air escapes through the attic and to the attic vents allowing the circulation of chilly air from the windows.
Or look at the weather for 2 days with the same weather and monitor temps with and without the fan on each day.
You can diagnose it by plugging other electrical appliances that are working into the same outlet and by plugging the fan into a different power outlet.
Turn your fan off and monitor the temperature in your attic up unitl 2pm or something then turn it on.
The downside of attic ventilation fans.
The whole house fan is installed inside the attic between the living space and ceiling.
Attic ventilation fans whether hard wired or powered by their own solar panels seem like a low cost and effective way to help keep your house cool.
Good insulation reduces fan effectiveness.
Once done test that the motor still works by plugging the motor into an extension cord that is connected to an outlet.
Whole house fans work on the principle of removing the hot and humid air out of the house.
However the utility of attic ventilation fans is actually quite a controversial topic.
If you re running an air conditioner you wouldn t want to have a whole house fan blowing that cooled air into your attic.
Step 2 test the thermostat.