Backdraft Non Return Damper 200 - Metal

A: The 200mm metal non-return damper is designed to create minimal airflow restriction when the exhaust fan is operating. The lightweight metal flap opens fully under normal fan pressure, allowing air to pass through with negligible resistance. Any slight pressure drop is minimal and will not noticeably affect the performance of a properly sized inline fan or exhaust system. The damper is engineered to balance effective backdraft prevention with maximum airflow efficiency in your HVAC ducting.

A: The main difference between the 200mm and 150mm backdraft non-return dampers is the duct size they fit. The 200mm model is designed for larger ducting systems that handle higher airflow volumes, typically used with 200mm inline fans and commercial ventilation setups. The 150mm version suits standard residential exhaust fan ductwork. Both are constructed from durable metal with spring-loaded flaps, but the 200mm variant allows greater air throughput while still preventing backdrafts effectively.

A: Yes, the 200mm Backdraft Non Return Damper Metal is perfectly suited for use with 200mm inline exhaust fan systems. Install it downstream from your inline fan, between the fan outlet and the external wall or roof vent. The metal damper will prevent backdrafts when the inline fan is turned off, keeping your ducted ventilation system sealed against outside air, insects, and weather. It is compatible with all standard 200mm round ducting and inline fans from brands like Airvent.

A: The Backdraft Non Return Damper 200mm Metal is specifically designed to prevent reverse airflow in 200mm round ducting systems. It features a spring-loaded metal flap that opens when air is pushed through by an exhaust fan and closes automatically when the fan is off, blocking cold drafts, insects, odours, and external contaminants from entering your home. This 200mm variant is ideal for larger ducting runs commonly used with inline fans, rangehood exhausts, and commercial ventilation setups requiring higher airflow capacity.