During the summer, the attic can be a major source of hot air. Gable vent fans are one way to ensure that the inside of your attic does not become overheated. They allow cool air to travel into the attic, cooling the whole house down.
One good reason to buy gable vent fans is cost. These fans are generally cheaper than other types of roof ventilation. You can also save money on installation, as it isn't hard to do it yourself. Gable vent fans also have a good running cost at 4 cents per hour.
Gable vent fans can ventilate a large space, providing slightly less than 1,300 cubic feet of cooled air every minute. For a small attic, you will only need one; for a larger attic, you may need more.
Gable attic fans are also convenient to use. Most are operated via a simple thermostat.