You think the forced attic ventilation is a paying proposition? The work but have they saved money on the AC?
I’ve been considering a fan in the attic or radiant barrier paint on the decking.
One argument against fans is that they pull air from inside the house to the attic with the negative pressure. Can’t see it with 20” or more of fiberglass insulation.
I wish I had put Koolply on when we redid the roof, I will on the addition that is upcoming. Not a believer in the encapsulated attic but use of mini-splits instead. Duct work does not belong in attics and does not belong much of anywhere. I’ll be replacing the R-2 junk with R-8 ducts this winter and freshening the insulation in the attic where I do have the old forced air split system. The addition will have a three zone cassette mini-split based system with Koolply decking and lots of foam.
Well, you raise some interesting points. All I can attest to is that our attic is so much cooler now that the electric fans are running. There’s 2 up there. Our house is about 2500 sq. ft. single story.
It seems the air that’s being forced out is the attic air. I don’t see how air can be pulled up from the house. The vent goes directly into the pump up there, as I understand it.
Those fans are in the roof. A long way from the inside of the house and again, I don’t see how the cooled inside air is being pulled up by the fans since it’s pretty much sealed between the house and the attic with the exception of the vent where the AC filter is.
I probably don’t know what I am talking about but our power bill is way down. New windows around the house and a new AC unit is certainly the major factors. Good luck.