LESLIE: Now we’ve got Doug from Rhode Island who’s got a question about an attic fan. How can we help you with that?
DOUG: Somebody gave me a new, 15-inch attic fan. And I’m considering installing it but I also wondered, the electricity I’m going to use to run the fan, it’s maybe a wash. I don’t know. In other words, is it economical to run this attic fan?
TOM: Yeah. I’ll tell you what, I don’t have a good opinion of attic fans because what we have found – do you have central air conditioning in your house?
DOUG: Yes.
TOM: Well, what’s been found is that if you turn the attic fan on in the summertime, that it depressurizes the attic but it doesn’t stop there. It’ll reach down through the insulation – it’ll find all the little cracks and crevices in that ceiling space – and it’ll reach down into your house and it will start drawing off air-conditioned air and actually drive up your cooling costs.
So, I’m glad you didn’t have to pay for the attic fan but I wouldn’t put it in, if it was me. I would just make sure that my attic was well-ventilated, using passive vents. The most preferred are ridge vents and soffit vents.
DOUG: Yeah, I’m trying – I have sufficient vents.
TOM: Yeah. Then I don’t think you should put it in. I don’t think it’s going to help you and it could potentially hurt you.
DOUG: OK. No, I understand exactly what you’re saying.
TOM: OK?
DOUG: Thank you for your time.
TOM: You’re welcome. Good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.
It takes hours (3) to cool the back of our house (bedrooms) at night. (72 degrees) in the summer. Any suggestions? we extended that part of the house 8 feet also added more insulation to no avail. I am thinking it is the attic heat that is causing the problem even though we have a ridge and vents at each end of the attic. Can you suggest cures for this problem?
I’m assuming you dont have AC. Have you considered a whole house fan? We run ours for an hour or two (on a timer) in the evenings when we go to bed and it cools the entire house down.
Attic fans shouldn’t be set to run during the heat of the day. They should run on a timer in the early morning hours, to draw in the cool overnight air. When the warmth of the day starts to increase, the fan should be shut off, and windows closed. This allows the ambient air to cool the indoor air, and remove heat load from furniture, walls, granite counters, etc. This will reduce the need to run the AC, and push the start time to later in the day.