The AC Infinity Backdraft Damper is a one-way airflow ducting insert designed to prevent cold drafts, debris, insects, and pests from entering ductwork when the connected fan is off. Built from black powder-coated galvanised steel with spring-loaded aluminium butterfly blades, it seats firmly inside standard round ducting using dual outer rubber gasket rings that create an airtight grip in either a horizontal or vertical orientation, without the need for tools, screws, or adhesive.
When the fan operates, the butterfly blades open with minimal airflow resistance, allowing exhaust air to pass through freely. When the fan stops, the spring-loaded blades close automatically, sealing the duct and blocking any return airflow, drafts, or debris. This makes the damper particularly valuable in grow tent setups where an inline fan exhausts through a wall or ceiling penetration. Without a damper in place, cold air, moisture, and insects can enter the tent through the exhaust duct whenever the fan is idle or between duty cycles.
The galvanised steel body and black powder coat finish provide long-term resistance to corrosion in high-humidity environments. Each damper can be fully or partially inserted into the ductwork, with the rubber rings holding it securely in place. Beyond grow rooms, the damper suits range hoods, bathroom exhaust fans, laundry dryers, and any HVAC application where one-way airflow control is required. For a grower running their exhaust fan on a timed schedule, fitting a backdraft damper at the wall exit keeps the tent sealed and pest-free during every off cycle.
A spring-loaded galvanised steel damper insert that prevents backdraft, pests, and debris from entering ducting when the fan is off.
One-Way Airflow
Blocks backdraft, pests, and debris when the fan is off.
Spring-Loaded Blades
Open with minimal airflow and close automatically when the fan stops.
Tool-Free Install
Dual rubber gasket rings grip the duct interior without screws or adhesive.
Back-Order
Back-OrderCurrently out of stock: back-order now to reserve yours from the next shipment.Estimated dispatch around 9 November.
Spring-loaded aluminium butterfly blades open with minimal airflow and close automatically when the fan stops
Dual outer rubber gasket rings create an airtight grip inside the duct without tools, screws, or adhesive
Mounts horizontally or vertically to suit any installation orientation
Can be fully or partially inserted to suit the depth of the installation
Compatible with range hoods, inline duct fans, bathroom fans, laundry dryers, and grow tent exhausts
Black powder-coated galvanised steel body resists corrosion in high-humidity environments
Directions for Use
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Insert the damper into the duct opening with the butterfly blades facing the direction of exhaust airflow. The blades must open in the direction air travels out.
Push the damper into the duct until the outer rubber gasket rings grip the duct interior firmly and the damper is seated securely.
The damper can be fully or partially inserted depending on your installation. The rubber rings hold it in position without the need for tools or adhesive.
If mounting vertically, position the hinge pin of the butterfly blades horizontally so the blades fall closed under gravity when airflow stops.
Run the fan and confirm the blades open freely with unobstructed airflow.
Stop the fan and confirm the blades close automatically, sealing the duct against backdraft, debris, and pests.
Technical Specifications
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AC Infinity Backdraft Damper 100 mm (4")
Product Model AC-BDD4-B
UPC Code 819137021303
Duct Opening Size 100 mm (4")
Product Length 12.8 cm (5.03 in)
AC Infinity Backdraft Damper 150 mm (6")
Product Model AC-BDD6-B
UPC Code 819137021310
Duct Opening Size 150 mm (6")
Product Length 12.8 cm (5.03 in)
AC Infinity Backdraft Damper 200 mm (8")
Product Model AC-BDD8-B
UPC Code 819137021327
Duct Opening Size 200 mm (8")
Product Length 12.8 cm (5.03 in)
All Models
Body Material Galvanised steel
Finish Black powder coat
Blades Spring-loaded aluminium butterfly
Gaskets Dual outer rubber rings
Mounting Horizontal or vertical
Installation Tool-free insertion
Colour Black
Shipping & Returns
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Check delivery options for the currently selected item and quantity.
Estimate is for this item and quantity only. Final whole-order freight is confirmed at checkout.
We have a 30-day return policy, which means you have 30 days after receiving your item to request a return.
To be eligible for a return, your item must be in the same condition that you received it, unused, with tags, and in its original packaging. You’ll also need the receipt or proof of purchase.
If your return is accepted, we’ll send you a return shipping label, as well as instructions on how and where to send your package. Items sent back to us without first requesting a return will not be accepted.
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Key Highlights
Directions for Use
Technical Specifications
