The spinning thing often seen on top of a chimney is typically a spinning chimney cowl. This specialized device is designed to improve chimney performance and prevent common issues, particularly downdraught.
What is a Spinning Chimney Cowl?
A spinning chimney cowl is a mechanical attachment fixed to the top of a chimney pot. Its primary function is to prevent wind from blowing down the chimney, which can cause smoke to back up into a property. These cowls are designed with rotating elements that react to wind, ensuring an upward draw in the flue.
How Spinning Cowls Work
The mechanism of a spinning cowl relies on wind power. When wind interacts with the cowl's design, it causes a part of the device to rotate. This rotation creates a low-pressure area at the chimney's opening, which helps to pull smoke and gases up and out of the flue, effectively combating downdraught. This prevents air from entering down the chimney, maintaining a consistent upward flow.
Types of Spinning Chimney Cowls
There are various designs of spinning chimney cowls, each with a slightly different approach to achieving the same goal:
- Aspirotor: This type features fins that, when caught by the wind, rotate a globe-like structure. This constant rotation actively works to prevent air from being forced down the chimney, ensuring a clear exit for smoke.
- Lobster Back Cowl: While not always spinning in the same continuous rotation as an Aspirotor, the Lobster Back cowl is designed to turn its opening away from the prevailing wind direction. This reorientation helps to prevent anti-downdraught by simply presenting a closed or angled surface to incoming wind.
Benefits of Installing a Spinning Chimney Cowl
Installing a spinning chimney cowl can offer several advantages for homeowners:
- Prevents Downdraught: The most significant benefit is the effective prevention of wind blowing down the chimney, which stops smoke from entering living spaces.
- Improves Draw: By creating a more consistent upward airflow, these cowls can improve the natural draw of a chimney, making fires burn more efficiently.
- Reduces Smoke Ingress: Less smoke backing into the room leads to a cleaner, safer, and more pleasant environment.
- Protection from Elements: Many cowls also act as a cap, preventing rain, birds, and debris from entering the chimney.
For more information on chimney cowls and their benefits, you can refer to resources on chimney maintenance and accessories.
