Attic Temperature Differential

Providing half air change per.

Attic temperature differential.

Calculations indicate that on a july day in texas a ventilation rate of one air change per minute for a typical attic using 95 degree f air will lower the peak attic temperature to about 101 degrees f. Attic temperature 0 f outdoors calculated difference. These images came from a presentation danny parker gave pdf on fsec s cool roof research the third graph shows attic temperatures from the middle of the attic for several different types of roofing as well as a sealed attic. Snow acts as an insulator.

Dropping the temperature from 120 150 degrees to roughly the same as the outside temperature will save you enough on your power bill to offset the purchase and installation charge. Ideal attic temperatures and humidity settings aren t always easy to maintain. A good sign is when you open your attic in the winter and you don t see any frost on the nails poking through. In an ideal world the attic temperature would be the same as the outside temperature.

In reality however variables get in the way. The frost is frozen condensation from the warm air meeting the cold air and not ventilating if that. Your insulating and heating cooling the house not the attic. Installing attic vents if you don t already have them is another way to assist in the movement of hot and cold air out of your attic.

The white roof lowered the attic temperature by about 20 f. Warner is right that the attic should be close to the outside temp. The layer of continuous insulation in the 2 4 wall shields the highly conductive steel stud from exposure to near outdoor temperature. 63 9 f as was the case for the ceiling cavity and eave space temperatures total r value does not tell the whole story.