Description
Manual inline balancing damper for duct runs where airflow needs to be set at commissioning and held there permanently. Position the blade to the desired restriction, lock it, walk away. No motor, no wiring, no controls, nothing to fail. Galvanized inline construction. Suitable for fresh air inlet and low-temperature exhaust air. 4"–20" including odd-inch sizes.
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Set and locked: stays balanced. The locking mechanism holds the blade against duct vibration and airstream pressure; it doesn't drift, doesn't get bumped, doesn't care what the control system does
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No motor, no wiring, no controls: nothing to fail electrically; a set-and-locked MBD will still be in exactly that position ten years later
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Adjustable and re-lockable: if system conditions change, unlock, reposition to the new balance point, and re-lock; no wiring to reconfigure, no controller setpoint to change
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Suitable for low-temperature exhaust air: handles cold and condensation-laden airstreams from HRV/ERV systems and cold-climate fresh air intakes without damage
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4"–20" including odd-inch sizes: matches round duct diameter exactly at the balance point; square and rectangular configurations available as factory special orders
Where it's used
→Fresh air intake flow limiting: set maximum fresh air volume to the code-required or design rate; locked restriction holds that rate regardless of system pressure variations
→HRV and ERV branch balancing: trim the higher-flow branch to match the lower at commissioning; permanently balanced without periodic electronic adjustment
→Supply and return airflow balancing: residential and light commercial systems; set at commissioning, stays balanced
→Low-temperature exhaust air restriction: fixed restriction in cold-climate or HRV exhaust runs where a motorized damper is not required
HAC-MBD: use for fixed balancing
✓Set at commissioning to a fixed restriction: stays there
✓Airflow balancing: trims a specific flow rate and holds it
✓Installs in the main duct run at the balance point
✓Does not respond to pressure changes. That's the point
HAC-BPD: use for pressure relief
→Opens and closes automatically based on duct static pressure
→System protection: relieves excess pressure when zones close
→Installs in a bypass branch, not in the main duct run
→Responds dynamically to changing system conditions
| Size | Part Number | Configuration |
|---|---|---|
| 4" | HAC-0400-MBD | Manual, adjustable locking mechanism, galvanized inline |
| 5" | HAC-0500-MBD | Manual, adjustable locking mechanism, galvanized inline |
| 6" | HAC-0600-MBD | Manual, adjustable locking mechanism, galvanized inline |
| 7" | HAC-0700-MBD | Manual, adjustable locking mechanism, galvanized inline |
| 8" | HAC-0800-MBD | Manual, adjustable locking mechanism, galvanized inline |
| 10" | HAC-1000-MBD | Manual, adjustable locking mechanism, galvanized inline |
| 12" | HAC-1200-MBD | Manual, adjustable locking mechanism, galvanized inline |
| 14" | HAC-1400-MBD | Manual, adjustable locking mechanism, galvanized inline |
| 16" | HAC-1600-MBD | Manual, adjustable locking mechanism, galvanized inline |
| 18" | HAC-1800-MBD | Manual, adjustable locking mechanism, galvanized inline |
| 20" | HAC-2000-MBD | Manual, adjustable locking mechanism, galvanized inline |
Select diameter only: all units identical in configuration. 9" is not available in this series. Square and rectangular configurations available as factory special orders.
Operation
Manual: set and lock at commissioning
Sizes
4"–20" incl. odd inches
Adjustment
Adjustable locking mechanism
Construction
Galvanized inline
Application
Fresh air inlet, low-temp exhaust
Warranty
10-year mechanical
Commission with instruments: set by flow reading, not blade angle. Use a flow hood, pitot tube traverse, or insertion flow meter appropriate for the duct size. Leave the locking mechanism loose through rough-in and startup. Set and lock only at final commissioning with the system running at design conditions. Need the dynamic pressure-relief version instead? See HAC-BPD.
10-year mechanical warranty
Made in Canada · No motor, no wiring, nothing to fail
Product image is representative only. Actual product may differ in appearance depending on size, configuration, and options selected at order.