Whole-house fan

A whole house fan is a type of fan, commonly venting into a building's attic, designed to circulate air in an entire house or other building.

This forces air from the living areas into the attic and out through the gable and/or soffit vents, while at the same time drawing air from the outside into the living areas through open windows.

Before the development of electrical power the principle of cooling a building by designing it to draw in cooler air from below and vent it from the top was known.

Thomas Jefferson, US president from 1801 to 1809, was personally involved in the designs of his residences at Monticello and Poplar Forest, and was aware of these techniques.

Monticello had a large central hall and aligned windows designed to allow a cooling air-current to pass through the house, with an octagonal cupola at the top of the house drawing hot air up and out through natural convection.