Choosing a 10 inch Backdraft Damper for a Bigger Run
Blade mass climbs with diameter, and at ten inches that becomes something to think about rather than ignore. Each blade is a larger plate than the same part in a six or an eight, and a larger plate takes more air to lift. Atmosphere give the requirement as four to eight hundredths of an inch of static pressure across the range. A well specified ten inch fan at full speed clears that comfortably. A ten inch fan turned down to a low night setting is the case to check. A damper that only half opens strangles the run, and the fan sounds fine while doing almost nothing. Test at the slowest speed the system will be asked to run. Beyond that the design is the same across the range. Two blades hang on independent hinges so one cannot hold the other open. Both seat onto a neoprene perimeter gasket for a quiet, tight closure.
Galvanized Steel, Installation and Keeping It Working
The body is galvanized steel, which is the right material for a part that sits inside a humid extraction duct for years. Zinc coating takes the corrosion that plain steel would not survive, and the stiffness keeps a plate this size from distorting and losing its seal. The whole assembly inserts into the duct rather than bolting to a flange. Installation is a push fit and a couple of screws rather than a fabrication job. Any orientation works, including a vertical riser. A few habits keep it doing its job. Support the duct either side so the damper is not carrying the weight of a sagging run. Keep the sealing face clean, since dust and resin build on it and a face that cannot seat leaks without making any noise about it. Check the blades swing freely at each filter change. A damper is the lowest cost part in a ventilation run and the easiest to forget about entirely.
Key Features
- Duct size: Ten inches, for a larger extraction or supply run
- Blade mass: Larger plates than a smaller size, so opening pressure matters more
- Opening pressure: Four to eight hundredths of an inch of static
- Low speed check: Test that it opens at the slowest speed the fan will run
- Blades: Two, each on its own independent hinge
- Seal: Neoprene perimeter gasket for a quiet, tight closure
- Body: Galvanized steel, chosen for a humid duct environment
- Mounting: Inserts into the duct, with no flange or transition needed
- Support: Hold the duct either side so the damper carries no weight
- Maintenance: Clean the sealing face and check the swing at each filter change
Technical Specifications
| Specification | Value |
|---|---|
| SKU | VTBDD10 |
| Duct diameter | 10 in |
| Brand | Atmosphere |
| Type | Round backdraft damper, duct insert |
| Material | Galvanized steel |
| Blades | Two, each on its own independent hinge |
| Seal | Neoprene perimeter gasket |
| Mounting | The whole assembly inserts into the duct |
| Orientation | Installs in any position |
| Opening pressure | 0.04 to 0.08 in of static pressure |
| Designed for | Atmosphere Vortex in-line fans and dryer exhaust ventilators |
| Barcode | 628507200053 |