Attic fan

An attic fan, is a fan that controls the heat level of a building's attic by removing the hot air. A thermostat is used to turn the fan off and on based on the heat level, while sometimes a manual switch is used. An attic fan can be gable mounted or roof mounted. Extra vents are required to draw in fresh air as the hot air is exhausted. Attic fans are typically used in warmer months when temperatures in an attic can get above . A fan may be installed in an attic for the purpose of cooling a whole house by venting hot air out via the attic. These fans are often called whole-house fans.
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. 

Wiring methods
Attic fans may be wired in different ways. Normally, the fan is wired directly into an electric circuit and is controlled by a thermostat commonly ranging from  to . It may also be hardwired but turned on and off using a switch. Another method is to have the fan plugged into an electric outlet mounted nearby. An environmentally friendly method is to wire a fan to a roof-mounted solar panel.

References

Category:HVAC
Category:Home appliances