We had planned on installing an in roof fan in our umfinished attic. A local contractor said that the soffit and ridge vents are adequate and that we would be defeating their purpose and that we should leave well enough alone.
Any opinions about this issue?
delta-T will take care of itself. if you have low-side venting, good soffit vents, and good high-side venting from a ridge vent or vent cuts near the top of the roof, you have a nice natural fan already. roof gets hot, hot air rises. this pulls in cooler air from the soffits. no problem.
your contractor is correct.
sig: if this is a new economy, how come they still want my old-fashioned money?
I will add that he is mostly correct. Adding the fan will not hurt, except for the electrical usage. As the fans are controlled by a thermostat they can be set to come on at a temperature that is beyond the natural convection abilities. Most of the time the attic will stay cool enough without the fan running at all but if it gets really hot, the fan will be able to draw more cool air into the attic than just the ridge and soffit vents.
i installed one in my attic and noticed a difference
it may be just the moving air i feel. but it feels cooler to me
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