A chimney cowl is a rotating cap on a chimney or ventilation pipe that turns with the wind, so the opening always faces away from the wind. This prevents downdraught (blowing smoke back down) and improves the draught and extraction.
Features
The cowl stands out for its rotating, self-aligning construction:
- Turns freely with the wind thanks to a vane or tail that orients the cap.
- The opening always faces away from the wind, counteracting downdraught.
- Improves natural draught and prevents smoke from blowing back.
- Usually made of weather-resistant metal such as stainless steel or zinc.
Application
The cowl is used at various flue and ventilation points:
- Chimneys of stoves and fireplaces for better smoke extraction.
- Mechanical and natural ventilation systems.
- Venting of the sewer system (soil vent pipes).
- Locations with strong wind or turbulence around the roof.
Related terms
- Chimney
- Ventilation
- Roof penetration
- Vent terminal
- Draught
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