Whirlybirds

Whirlybirds, also known as ventilation turbines or whirlybird turbines, are a type of mechanical roof vent designed to ventilate and cool buildings. They are typically mounted on rooftops or walls and use spinning vanes or impellers to draw hot air and moisture out of the building.

Whirlybirds are often used in conjunction with other ventilation systems, such as exhaust fans, and are commonly found in residential and commercial buildings in warm and humid climates. They are particularly useful in areas where overhead conditions are difficult to ventilate, such as in attics and dormer valleys.

The impeller of a whirlybird typically consists of 10 to 20 curved vanes attached to a central hub, which is connected to a motor. The motor spins the impeller, creating a low-pressure area behind it, which draws in surrounding air. The air is then thrown out of the roof, often by the action of a weather vane.

Whirlybirds can be powered by either electricity or wind, with some models featuring a manual override for use in electricity-free situations. They are relatively quiet in operation, typically producing a maximum sound level of around 40 decibels. However, some users have reported that the noise generated by whirlybirds can vary depending on factors such as wind speed and impeller design.

Overall, whirlybirds are a popular and effective solution for ventilating buildings in warm and humid climates, offering a quiet and reliable means of removing hot air and moisture.