Attic Ventialtion and Air Conditioning Costs
Attic ventilation can have a surprising impact on both roof life and attic temperature. Often, attic temps can reach as high as 150 to 160 degrees if poor ventilation is present. These high temperatures will prematurely age asphalt shingles and other roofing materials, causing shingles to last as little as half of their expected life.
The extra load on the AC system can be substantial also. If your AC system works harder to cool your home, it will not last as long, and replacement of an AC system is quite expensive.
If you’re feeling smug because your home was built in the last few years and has a tile roof and good insulation, perhaps you should read on. Many newer homes in this area have inadequate attic venting, thus experiencing inflated air conditioning costs driven up by the high attic temperatures. Adequate insulation only slows the transfer of heat, it doesn’t stop it. City inspectors usually give little attention to this concern and many roofers that I deal with don’t understand the Building Code for ventilation (if enough of you start calling them, I’ll bet they learn it real quickly).
Air conditioning systems should last about 15-20 years. If yours failed prematurely, was it because the attic temperature caused it to cycle off and on too rapidly?
How can you know if your attic is properly vented? Check your attic temperature on a hot summer day. If you say, “You’ve got to be kidding! I wouldn’t possibly go up there in the summer,” then perhaps you have the perfect attic--perfect that is, for the air conditioning repairman and your electric utility.
Ideal attic temperatures shouldn’t be more than 10-20 degrees hotter than outside air on a summer day.
If yours is higher, then it’s time to think about venting your attic properly.
Attic ventilation-pay once to get it right or continue to pay the electric utility and the air conditioning repairman-it’s your choice.