How Do I Get the Hot Air Out of My Attic?

During the summer months, hot air builds up in the attic of your home. Homes have venting along the roof ridge, within the gable and along the soffit. The vents are screened or louvered to allow air to pass through. This type of passive venting is based on the principle that hot air rises and passes through these open vents. Unfortunately, hot air moves slowly, so the attic continues to heat. By adding devices designed to move air, you can get the hot air out of your attic more quickly.

Gable vents are part of a home's passive venting system.
  1. Ensure you have a sufficient amount of vents for the size of your attic. Paul Bianchina, writing for the real estate trade paper, "Inman," recommends 1 square foot of ventilation for every 300 square feet of attic area. The ventilation should also be divided between lower vents, such as soffit venting, and the higher vents, such as those along the roof ridge.

  2. Install a whole house fan. A whole house fan pulls air in from the outside, which is cooled by the movement. The motion of the air pushes the warm air in the home upward into the attic. The air remains in motion via the fan system and pushes the hot air out of the attic venting system.

  3. Add roof turbines to the home. Wind powered roof turbines, also referred to as whirlybird vents pull hot air out of the attic. Roof turbines are only effective, however, when there is enough wind to turn the blades quickly enough to move the air upward and out of the attic space.

  4. Create more air movement within the attic through the use of electric attic fans. Electric attic fans pull air from soffit vents, cooling it through movement while simultaneously moving heated air out of the upper vents. Maximize the efficiency of the fans by ensuring the soffit vents are fully open.

  5. Install solar attic fans. Solar attic fans operate on the same principle as electric fans. The difference is a solar fan contains a small solar panel that powers the fan. It does not require any power from your electrical system.

  6. Reduce the solar heat gain in your attic with reflective insulation. As the sun beats down on your roof, the roofing and attic materials retain that heat which then heats the air in the attic. Installed on the underside of the rafters, the reflective barrier reduces the amount of heat entering the attic, effectively reducing solar heat gain. With less heated air in the attic, the passive and active venting systems work more efficiently.