by Dan Jape of Reliable Heating & Air
In the past two years, many homes in the Atlanta area have had new roofs installed due to the hail damage and storms that have hit us hard. With these new roofs came a very harmful side effect sold to the unsuspecting homeowner by roofing companies: a scorching hot attic. Most homes in Atlanta have a power assisted fan installed that exhausts hot air in the summer and keeps the temperature down in the attic which allows the air conditioning to work properly. The duct work in many homes is actually in the attic and by having proper ventilation, the air coming out of the vents can actually be 10 to 15 degrees cooler. Attics without these fans can approach 160 degrees in the middle of the afternoon.
The problem has come from the fact the majority of roofing companies have convinced the homeowner they no longer need power fans, instead replacing them with an inferior venting system called “ridge vents”. A ridge vent is simply a cap that goes over a hole cut along the peak of the roofing shingles. It is supposed to allow super heated air to naturally rise up and out the roof of your home through convection instead of using an electric fan to blow the air out of the roof. While some heat is exhausted, nowhere near as much is actually taken out of the attic when using a power fan and the result is a hot home and an air conditioner that has to run twice as long as it should under proper conditions. Also, the shingles can get too hot, shortening the life of the new roof. Roofers promote ridge vents because they have a high level of profit for the roofing companies, but this passive venting system does not do an adequate job for most homes in Atlanta. We see home after home that can’t cool to the level it used to before the change of the attic venting system. To make matters worse, there is much misinformation on the internet about attic ventilation which makes it more difficult to know what to believe.
There are power fans that mount in the gable vents already in the attic and there are also vents that need a hole cut through the roof and are usually mounted near the top or peak of the roof. These fans draw cooler air from under the overhang or soffit into the roof and blow up to 2000 cfm of air out when needed. They are controlled by thermostats mounted in the attics that turn the fans on at somewhere around 110 degrees. Critics of these fans complain they use too much electricity and the ridge vents do not, but time after time we have noted the temperature in the attic is 20 to 40 degrees warmer without power assisted fans. Whatever amount of electricity these fans do use will come back to you with lower cooling bills and reduced run time.
Do not let anyone convince you to change from power ventilation to passive ridge vents for any reason. If you already have, consider looking into changing back to power assisted fans, as it will bring you enhanced comfort, lower temperatures and reduced power bills for years to come.