A Whirlybird is one of the easiest and most cost-effective ways to ventilate homes and buildings.
The Whirlybird is a vent that is installed on roofs to extract the heat from ceiling cavities. The dome is fitted with fins that spin when they catch the wind. This then creates a vacuum which sucks up warm air from the roof cavity and releases it into the atmosphere, thus cooling the building/room below.
The Whirlybird is aluminum, so rust will never be a concern, and once it installed it is completely free to operate.