Attic fan
Mechanical attic ventilation fans may be powered in a variety of different ways. Most attic vents fitted to homes are powered off electricity supplied by the power meter. A trend towards solar-powered attic ventilators is observable in the interest of conserving electricity and lowering monthly utility bills. Wind-powered roof turbines, often referred to as "whirly-birds", are also used to ventilate attics and other confined spaces.