What is a Gable Fan?

A gable fan is a cheap and effective way to keep air circulating through your attic. Not only can this help you keep your house cooler in the summer, it can actually prolong the life of your roof and reduce wear on your attic.

In the hot summer months, the air in the attic can become stagnant and superheated without a fan, reaching temperatures as high as 150 degrees Fahrenheit. This excess heat drives up your energy costs for air conditioning and can damage the shingles on your roof and the wooden trusses in your attic. Plus, it simply makes your home uncomfortably warm.

Gable fans vent this superheated air back outside, creating a positive air-flow through your attic. Mounted on the gable (that triangular wall between the edges of your home's sloping roof), these fans move large quantities of air through a relatively small opening, making them far more effective than simple passive venting. As the heat is expelled, cooler air is drawn in through the soffit vents to replace it.

Using a gable fan can reduce the temperature of your attic by as much as 60 degrees. This, in turn, can reduce your home interior temperature by 10 degrees and cut your air-conditioning costs by 30%. Circulating the air through your attic will also keep your shingles cooler and prevent your trusses from drying out.

The advantages of gable fans can extend to the winter months as well. In cold weather, moisture can build up in an improperly ventilated attic, causing mold to grow and wood to rot. In extreme cases, this excess moisture can freeze, leading to ice in the insulation. But with the use of a humidistat, a gable fan can reduce this excess moisture and keep your attic dry.

Unless your home already has a gable vent in place, the gable fan will typically be more difficult to install than a simple roof fan. Also, because gable fans receive less sun exposure than roof fans, the options for solar power are limited. However, because of its design, the gable fan has less air-flow restriction than the roof fan, making it more energy efficient. The gable fan is also considerably larger, which means it can move more cubic feet of air per minute.