Attic Temperature Too Hot

Poor insulation is usually the culprit although if you enter the attic on sunny winter day your attic space can be warmed by the sun more than your furnace.

Attic temperature too hot.

That is certainly too hot but how hot is ok. The thermostat will usually start at 95 degrees fahrenheit which is the temperature that the attic fan usually starts at. If it s 90 degrees outside the attic temperatures shouldn t. But by adding powered attic fans you will draw more air into the attic.

Using insulation only keeps the attic s heat from traveling through your home. Unless your roofing system has insulation on the roofing deck and is designed without ventilation your furnace should not be heating your attic. An overheated attic can bake asphalt shingles on the roof and cause them to deteriorate. If hot air is allowed to sit in your attic it could overheat the shingles on your roof and cause damage.

At the very best conventionally ventilated attics can never be cooler than the outside air temperature. Ideal attic temperatures shouldn t be more than 10 to 20 degrees hotter than outside temperatures. If your attic soars above 100 degrees and reaches the 150 mark its time to consult professionals. An unventilated attic can reach 150 degrees in the heat of summer 50 degrees higher than it should be.

Thanks to the radiant heat affect attic temperatures on a 100 degree day can reach 170 degrees or more. Just make sure the ceiling is airtight and fully insulated and the temperature in the attic doesn t matter much. Note excessive heat. Hang pencil and paper next to the thermometer and record the outdoor and attic temperatures for several hot days.

This is because the attic is essentially open to the outside air. Whether it s 110 f or 130 f there s not much difference in the amount of heat flowing from the attic to the living space below.