Attic Temperature Differential Winter

Is there any rule of thumb for attic temps compared to outside temp.

Attic temperature differential winter.

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. Ideal attic temperatures shouldn t be more than 10 to 20 degrees hotter than outside temperatures. Temperatures were measured using thermocouples and recorded over a 3 year period from october 1991 through september 1994 using a datalogger multiplexer device. When i left for work in the morning outside was 73f inside 74f attic 75f i m happy with the interior only creeping up 4 degrees a c off windows closed is the 21 degree differential temp ideal for an attic in the n.

Your attic temperature should be at or near the outside air temperature if it is well ventilated and does not leak warm air into the attic from below. Yesterday s outside temp topped at 91 f inside temp 78 f a c off all windows closed and attic 112 f. I only had r 19 up there added another 30 on top of it and noticed the old insulation was crammed right tight to the sheathing. Now if the ridge vent is only partial or if the attic air temperature is excessive 20 degrees higher than the outside air fans may prove beneficial pick the right fan.

Kingmurphy 04 32am 11 20 05. Interior attic air exterior air inner and outer sheathing and internal rafter temperatures of black and white shingled chambers were monitored. The white roof lowered the attic temperature by about 20 f. As snow accumulates it alters the temperature profile of an attic and roof surface.

After the worst winter we ve had in a long time and the ice ripping the gutter and fascia board off my house i d had enough.