Solar ventilation fans provide an energy-free way to cool an attic, prolong the life of a roof and save wear and tear on heating and air conditioning equipment. These fans are sold fully assembled and can be installed in less than an hour.
Solar fans gather energy from the sun using photo-voltaic panels, just like a typical solar roof. The energy rotates the fan, which pulls the hot air out of the attic. The system is most effective if used with soffit vents that are placed under the eaves along the roof's perimeter. The soffit vents draw cool air in, forcing the hot air towards the solar vents.
These ventilation fans come in three basic mounting types. The self-flashing base is used on sloped roofs where there is little chance of pooling water. The curb mount fan sits inside of an elevated base and is used on flat roofs, or those with little slope. The curb "box" prevents water from seeping into the attic. Gable mount solar attic fans are placed behind the gable vents, found in the triangular areas on either side of a peaked roof.
Solar fans work best in areas that get lots of sunlight. Homeowners in northern latitudes should consider getting a backup fan system for the snowy or rainy winter months. Backup fans are also advised in hot and humid areas that need fans running around the clock.