solar powered roof vents

A solar chimney is a way of improving the natural ventilation of buildings by using convection of air heated by passive solar energy. The solar chimney has been in use for centuries, particularly in the Middle east, as well as by the Romans.

Description

In its simplest form, the solar chimney consists of a black-painted chimney. During the day solar energy heats the chimney and the air within it, creating an updraft of air in the chimney. The suction created at the chimney's base can be used to ventilate and cool the building below. Air Vent: Solar Powered Attic Vent. In most parts of the world it is easier to harness wind power for such ventillation, but on hot windless days such a chimney can provide ventilation where otherwise there would be none.

A principle has been proposed for solar power generation, using a large greenhouse at the base rather than relying solely on heating the chimney itself. (For further information on this issue, see Solar updraft tower. )

Solar chimney and sustainable architecture

A Solar chimney can serve many purposes. Direct gain warms air inside the chimney causing it to rise out the top and drawing air in from the bottom.