# What temp should I set my attic fan?



## pcampbell (Feb 7, 2008)

Our HVAC system is in unconditioned space in the attic and we live in NJ where it gets relatively hot and cold. The previous owner had it set to 110 F which seems too hot. I went up there right now and it's very hot I turned it down to around 95 and it clicks on right away. I don't know exactly how hot it is upstairs. Secondly should I open window(s) upstairs? Assuming it's hotter inside than outside, opening the windows would allow it to suck outside air, hopefully rather than sucking our conditioned air downstairs?

The fan is pretty powerful, says 1350 CFM, not sure of the amp draw.


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## skymaster (Jun 6, 2007)

PC, even tho it is hot up there I would reset it to between 110 and 120. The reason is simply that once it warms outside than fan is going to be running 24/7 if set at 95. Attic space gets real hot real fast even when it is 70 outside. Easily 25 degrees hotter than outside temps. Your electric bill is going to go skyhigh PLUS you will burn that fan up real quick. They are rated only for intermitent running NOT continuous.


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## pcampbell (Feb 7, 2008)

Good point, Thanks. Do you know if we should have the windows cracked up there. Assuming it is going to be hotter inside than out for the majority of the summer that would allow cooler air in. Again our ducts are in this space so they will be affected by the weather although they are well sealed and insulated with R6.


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## skymaster (Jun 6, 2007)

keeping window open cant hurt as long as you have them screened over, and setup to prevent rain from getting in


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## Super33 (May 15, 2008)

If you crack open a window up there then what's stopping a burglar from entering through it and accessing your house via the access hole?


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## pcampbell (Feb 7, 2008)

I was talking about the attic, so about 25 feet of siding  Also our windows have the little stop tab things so you can crack it but not allow it to be opened further.


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## 8 Ball (May 17, 2008)

I have one. I set mine at 110. There is a adjustment on it to change the off setpoint, set mine at 10 degrees. 

Opening windows up there will allow for natural cross ventilation, and the fan should only run when you need it. 

It should not effect you air handler, its sealed and insulated.


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