Description
Keep the grow room sealed when the fan is off
This backdraft damper fits inline into a standard round duct run and uses two galvanised steel butterfly blades to seal the outlet automatically whenever the fan isn't running. The moment airflow stops, the blades close, stopping outside air, insects and odour finding their way back into the grow space through an idle extraction line.
It's a passive part — no power, no controller, nothing to set up — that simply does its job every time the fan cycles off, which makes it a cheap and permanent fix for the smell and bug-ingress problems that come from running extraction on a timer or thermostat.
Key Benefits
- Automatic butterfly blades seal the duct when the fan stops
- Stops odour escaping and outside air or bugs getting in
- Galvanised steel construction for durability
- No power or controls needed — fully passive operation
- Fits standard round ducting
Technical Specifications
- Type: inline backdraft damper (one-way shutter)
- Shutter: two butterfly blades on a central support
- Operation: opens with the fan's airflow, closes when the fan stops
- Power: none, fully passive
- Material: galvanised steel
- Fitting: duct clip on flexible ducting, or a female-female coupling on rigid ducting
- Position: near the extraction outlet, facing the direction of airflow
| By size | 100mm | 125mm | 150mm |
|---|---|---|---|
| Duct size | 100 mm (4 in) | 125 mm (5 in) | 150 mm (6 in) |
| By size | 200mm | 250mm | 315mm |
|---|---|---|---|
| Duct size | 200 mm (8 in) | 250 mm (10 in) | 315 mm (12 in) |
