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My attic is super hot, it doesn't have radiant barrier, ridge vent or attic roof fan
I'm looking into installing attic roof fan
But it got me wondering ... I think one 1600 CFM fan would be good enough
But I've seen a few houses with 2-4 fans
If I'm going to install one attic roof fan
Should I go ahead and install two of them?
My attic is super hot, it doesn't have radiant barrier, ridge vent or attic roof fan
I'm looking into installing attic roof fan
But it got me wondering ... I think one 1600 CFM fan would be good enough
But I've seen a few houses with 2-4 fans
If I'm going to install one attic roof fan
Should I go ahead and install two of them?
The attic is small, maybe 800sq ft
But it connects to a side attic that is about 800sq ft
1600CFM should be good, but I can go ahead and install two of them and set them at different temperature
So the 2nd one only turns on when it's really hot
The most important point to be made here- power roof ventilators are mechanical appliances (translation- they WILL FAIL!). I strongly suggest using a passive system (convection); which is a combination of soffit vents and ridge vents.
I have soffit vents and ridge roof and they make huge difference. Plus good attic insulation. Fans never made any difference. Would not invest in those.
You're going to have to do more research or consult a pro. Attic fans are only part of the equation, you need to consider the intake of fresh air and flow. Too many attic exhaust types can cause fresh air to pull from the lower exhaust instead of the soffits. For instance, a ridge vent or turbine set higher than a gable vent will pull air from the gable. I've learned this from experience below:
2012 - bought my first house, a mid-century ranch house with passive soffits and two gable vents. Attic would get up to 135 degrees. I installed a solar powered gable fan that thermostatically turns on at temps about 80 degrees or when humidity reaches above 75%, it cycles on every 6 minutes using house power when the sun isn't available. Added more insulation to the attic floor. Brought the attic temperature down to 120 degrees.
2014 - added a 1,500 CFM whole house fan that exhausts into the attic. Insufficient attic exhausts caused attic air to vent through the intake soffits when the fan was on. I added two turbine fans about 10 feet inward from the gable vents. Seems to have done the trick. Attic temperature now does not exceed 115 degrees.
Why install any power vents at all? If you're going to use electricity to lower your electric bill is pretty ......not so smart. There are many ways to lower the attic temps if that's the goal. Radiant barriers are the best. FWIW, if you vent the ambient air in the attic, it's replaced by even more hot air. Why? Because the attic insulation is subject to the radiant heat waves coming thru the decking. The insulation is what is generating the heat, per Building Science seminars. Their fix is to completely seal the attic- zero vents, but install a radiant barrier decking. I've been in their test houses- it works, doesn't mean I totally understand it but the sealed attic I was in was cooler than the outside air. And this was on a 100F+ day. Common sense has a tendency to tell you that a sealed attic should be like a microwave and the heat unbearable. Not so in reality, as long as you have a good radiant barrier.
Lots of reading here: https://buildingscience.com/
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