Home energy

Attic temperature.


You probably dont think much about attic temperature, but it has a lot to do with your summer cooling load. The attic can get hot from the sun beating down on those asphalt shingles (another petroleum product that could start to get expensive). The shingles get so hot they radiate the heat into your attic. Without adequate ventilation the attic will get much hotter than the ambient air outside.


The problem with a hot attic is that this heat seeps into your house and needs to be cooled by the Air conditioning. Also most air conditioning blowers - and thus the feeding and returning air ducts are also located in the attic spaces. Although most modern air ducts are insulated (as are most attic floors) this insulation just slows the seepage - but doesnt stop it.


Some companies sell attic fans, some are even solar powered (clever!)

But I wanted to know for myself how bad my problem was. So I bought a little inside-outside thermometer

On a typical 80F day in late may - with lots of sun and little wind, my attic gets up to 110F!

with wind or cloud its usually much less like 95F. Still compared with the ambient temp of mid 80s thats a significant extra load to put on all that insulation.


Try it yourself - thermometers are about $10 to $15.