Advice on cutting my cooling costs - Page 2

Phantom · 11-30-10, 12:43 PM

Quote:

Originally Posted by mrd

Attic fans are discouraged by many builders, as they create a negative pressure and suck conditioned air out of the house. The negative pressure may or may not outweigh the reduced delta-T of a cooler attic

You do not run an attic fan to cool the attic it is used primarily to pull fresh cooler air in to the house a side benefit is that the attic is cooler so it does not passively heat the house. Also you do NOT run it when the AC is set to come on.

Daox · 11-30-10, 12:47 PM

You're thinking of a whole house fan that draws air into the house as it exhausts it into the attic.

An attic fan is specifically for keeping the attic cool to reduce the heat gain from a hot attic.

Xringer · 11-30-10, 10:03 PM

Quote:

Originally Posted by mrd

Attic fans are discouraged by many builders, as they create a negative pressure and suck conditioned air out of the house. The negative pressure may or may not outweigh the reduced delta-T of a cooler attic, and positive house pressure in the summer is preferred.

Sealing air leaks is always beneficial, and solar shading can make a tremendous difference in the amount of heat your air conditioner fights to remove. Also, an air conditioner that runs constantly is actually desired (as long as it can keep the house at your desired temperature) as it does a better job of dehumidifying the longer it runs.

I can't see how anyone could install an Attic Fan without a good source of outdoor air input.?.
But, If downstairs air was to get up there, it would likely come in via the attic pull-down stairs. (In my house anyways).

That's going to be air that is up near the ceiling. And, it's going to be warm air. Some of the warmest air in the house.

I like the idea of "solar shading".. One good way is to install some PV..

11-30-10, 12:47 PM	#12
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