Attic Fan Replacement

Identification

• As the highest room in your house, the attic heats up the quickest due to its close proximity to the sun's rays. Infrared energy travels through the rooftop, heating trusses, rafters and roof sheathing to blistering temperatures. Moreover, hot air is less dense than cool air, and tends to rise towards the ceilings and upper levels of the home. If roof shingles begin to curl at the corners, or bulges appear in the felt and shingles on top of the sheathing seams, then it may be time to replace your fan. These are signs that your attic is too hot and your fan is ill-suited for reducing your attic's temperature.

Function

• Attic fans help cool down insulation and other objects in the room by creating and blowing moisture around in the air. They also work in conjunction with soffit vents, which help move and replace indoor air with outdoor ventilation. Prior to replacing an attic fan, check the size and placement of vents on your roof. For every 300 square feet of attic area, there should be at least one square foot of roof vent area, according to “Popular Mechanics” magazine writer Merle Henkenius. Noting the number and types of vents in your attic will help you determine what type of fan works best in with your current insulation and venting system.

Types

• You can find two main designs of attic fans on the market, according to Henkenius. The first are attic fans designed for roofs. These attic fans rest on plastic or sheet metal bases that act as roof flashing. The second are gable-wall fans, which are installed and mounted at gable vents. They are typically triangular vents located in the wall directly under the tip of the roof. Gable-wall fans are positioned and secured with framing studs over the gable vent's louvered opening. You can also purchase electric-powered attic fans, or attic fans powered by solar energy or wind turbines.

Benefits

• Attic temperatures can climb as high as 150 degrees Fahrenheit and account for 20 percent of your cooling bill, according to Henkenius. Consequently, replacing your attic fan with a more energy-efficient model will save on energy costs in the long run. Some attic fans contain humidistats for controlling humidity in the winter, and thermostats for monitoring hot temperatures during the summer. Replacing your attic fan with the right model will exhaust the hot air and make your home more comfortable during extreme weather. In its list of heating tips for "How to Conserve Energy at Home," Northwest Arkansas Community College states, “Depending on the size of your home, you can save 3 percent on your cooling costs for every degree you raise your thermostat in the summer. Raising the thermostat from 73 to 78 degrees can mean savings of up to 15 percent in cooling costs.”