ft. of venting (technically, "net free vent area," or NFVA) for each 150 sq. ft. of attic. In some circumstances, you can have less, but we recommend the 1:150 ratio. So in a house with a 1,500-sq.- ...

A few years ago, I was helping a friend install baffles around her soffit vents. In the middle of the day, neither of us could stay in the attic longer than a few minutes. We didn't measure the ...