Attic Temperature Too Hot

Using insulation only keeps the attic s heat from traveling through your home.

Attic temperature too hot.

This is because the attic is essentially open to the outside air. That is certainly too hot but how hot is ok. In addition hot air in your attic could increase moisture levels which could result in wood rot and mold growth. 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.

Ideal attic temperatures shouldn t be more than 10 to 20 degrees hotter than outside temperatures. An overheated attic can bake asphalt shingles on the roof and cause them to deteriorate. Unless your roofing system has insulation on the roofing deck and is designed without ventilation your furnace should not be heating your attic. If it s 90 degrees outside the attic temperatures shouldn t.

Note excessive heat. The thermostat will usually start at 95 degrees fahrenheit which is the temperature that the attic fan usually starts at. 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. Thanks to the radiant heat affect attic temperatures on a 100 degree day can reach 170 degrees or more.

And it can cause your air conditioner to work harder than it needs to and send your energy bills soaring with the temperature. At the very best conventionally ventilated attics can never be cooler than the outside air temperature. Just make sure the ceiling is airtight and fully insulated and the temperature in the attic doesn t matter much. But by adding powered attic fans you will draw more air into the attic.

Hang pencil and paper next to the thermometer and record the outdoor and attic temperatures for several hot days. An unventilated attic can reach 150 degrees in the heat of summer 50 degrees higher than it should be.