Description
Product image is representative only. Actual product may differ in appearance depending on size, configuration, and options selected at order.
CSA-certified motorized fresh air damper that installs at the exterior wall penetration — hood and damper combined in one unit. No separate exterior hood required. One wall opening, one CSA-certified assembly, one control point. 24 Vac spring return, 4"–9", PO or PC action.
✓ Seals at the building wall — no passive hood opening exposed to outdoor air between ventilation cycles; no cold air column sitting in the duct run
✓ One unit replaces two — eliminates the separate exterior hood and inline damper that a standard HAC + OOH installation requires
✓ Same patented Hoyme spring motor drive — stall-protected, nylon bearings, engineered for freeze-thaw cycling and outdoor temperature exposure
✓ CSA certified — complete assembly — covers Canadian and US installations; not a certified actuator inside an uncertified enclosure
✓ PO or PC action, end switch and relay available — all factory-installed; specify at order, cannot be changed after installation
✓ MAC-L available — factory-insulated body for cold climate installs where condensation on the damper body is a concern; specify at order
Confirm PO vs. PC before ordering. The action is factory-set and cannot be changed after installation. Power Open (PO) is correct for the vast majority of fresh air intake and make-up air applications — the duct seals when the system is off. Power Close (PC) is used only when fail-open on power loss is required by the system design. An installed unit with the wrong action cannot be reversed in the field — replacement is the only correction.
Choose MAC when…
✓Damper at the exterior wall penetration is preferred
✓Single unit covers both termination and control
✓Tightest possible exterior air seal is a priority
✓Retrofit where adding a second interior unit is impractical
Choose HAC + OOH when…
→Damper needs to be in the duct run, accessible indoors
→Separate exterior hood already part of the design
→Sizes above 9" required
→Interior control point preferred for new construction
Key Advantage
Seals at the wall — no open hood between cycles
Sizes
4"–9"
Voltage
24 Vac
Action
PO or PC
Certification
CSA — complete assembly
Insulated version
MAC-L — specify at order
Need an ADP relay adaptor? For ventilation code compliance — fresh air damper interlocked with furnace fan — the ADP-0241-S5A sequences the MAC open first, proves position via end switch, then energizes the furnace fan to prevent cold air dump. Order the SPO or SPC variant when using an ADP adaptor.
2-year electrical · 10-year mechanical warranty
Made in Canada · 40+ years field-proven in Canadian climates