Power Roof Vent Fans
I live in Atlanta GA in a two story house built in 1984. I replaced my roof about 2 1/2 years ago and went from black to an almost white shingle. The roofing contractor told me since I had a high pitched roof with less than 40 ft. of ridge line that installing ridge venting was not recommended. Also you cannot have a ridge vent and a power vent. This will only force air flow at the peak of the roof. He reinstalled a new power vent.
I have since read and been told by many that these are not very good since they remove conditioned air from the second floor. I have installed radiant barrier in the attic on the underside of the rafters and left the power vent access clear. The unit will turn on when the attic temp at the thermostat hits 100 degrees.
Question 1: Was the roofing contractor correct?
Question 2: What options do I have now…. Box vents, retrofit a whirley bird vent?
Your feedback is greatly appreciated
Scott Razzino
GBA Detail Library
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Replies
Scott,
Question 1: "Was the roofing contractor correct?"
A. I'm not sure what you mean. If you are asking whether the roofer was correct when he said that it didn't make any sense to install a ridge vent on your house, we need more information. You haven't really explained the roofer's reasoning. If you are asking whether your roofing contractor was correct to install a powered attic ventilator, the answer is no.
Question 2: "What options do I have now.... Box vents, retrofit a whirley bird vent?"
A. You have lots of options, but you haven't described any problems. What problem are you trying to solve?
Here are some reactions to what you have said:
1. You haven't mentioned soffit vents. It doesn't make any sense to install a ridge vent unless you have soffit vents.
2. Powered attic ventilators always use more electricity than they save, so be sure to unplug that fan or cut the cord. (For more information on powered attic ventilators, see Martin’s Useless Products List and Are Solar-Powered Attic Ventilators Green?)
3. If you are worried about the fact that a hot attic makes it hard to cool your house, then your best measures are to seal the seams of any attic ductwork; increase the thickness of the insulation on your attic ducts; seal the air leaks in your ceiling; and increase the depth of the insulation on your attic floor.