Attic Temperature Differential Winter

The cooling load for a home air conditioner depends on the difference in temperature between the inside and outside air and reduction of attic temperatures from 155 degrees to 105 degrees f will result in a significant reduction in cooling load.

Attic temperature differential winter.

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. 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. Interior attic air exterior air inner and outer sheathing and internal rafter temperatures of black and white shingled chambers were monitored. If your attic soars above 100 degrees and reaches the 150 mark its time to consult.

Temperatures were measured using thermocouples and recorded over a 3 year period from october 1991 through september 1994 using a datalogger multiplexer device. 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. 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. Yesterday s outside temp topped at 91 f inside temp 78 f a c off all windows closed and attic 112 f.

Snowpack on a roof covering vents of any type alters the airflow from ventilation thus altering the. The white roof lowered the attic temperature by about 20 f. Ideal attic temperatures shouldn t be more than 10 to 20 degrees hotter than outside temperatures. Kingmurphy 04 32am 11 20 05.

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.