CSA Certified · Factory Insulated · Cold Climate

HAC-L
Insulated Inline
Fresh Air Damper

24 Vac · Factory-Insulated Body · CSA Certified · 2"–9"

✓Factory insulation applied before assembly — not field-wrapped

✓Stops condensation on the damper body in cold climates and unconditioned spaces

✓Same CSA-certified Hoyme drive as the standard HAC — everything else is identical

✓PO or PC spring return — cannot be changed after installation

✓End switch and relay options available (relay not available on 2" and 3")

✓Sizes 2"–9" — matches standard residential and light commercial round duct

✓2-year electrical / 10-year mechanical warranty

Hoyme HAC-L Insulated Inline Fresh Air Damper — factory-insulated body for cold climate installations

Is this the right product?

✔ Right product if

You need a CSA-certified 24 Vac motorized inline fresh air damper in sizes 2"–9" and the damper location is in unconditioned or semi-conditioned space — cold climate, near an exterior wall, or any location where the damper body will be exposed to temperatures that cause condensation.

✗ Not this product if

Damper is in conditioned mechanical space with no condensation risk → use the standard HAC — same drive, less expensive.

120 Vac site with insulation required → see HAC-12L

What It Does

Where condensation forms and callbacks start — stop it at the damper before the first winter.

The HAC-L is the cold-climate version of the standard HAC inline damper. The damper body carries factory insulation — applied before assembly, not wrapped in the field — reducing condensation risk and heat loss at the damper location. Everything else is identical to the standard HAC: the patented Hoyme 24 Vac spring return drive, CSA-certified assembly, same PO/PC configuration, same end switch and relay options. You get the insulation without giving up anything else.

A motorized fresh air damper in an unconditioned mechanical room, crawlspace, or near an exterior wall is exposed to the same temperature differential that causes condensation on cold water pipes. Moisture on the blade and seal surfaces leads to corrosion, frost buildup on blade edges in hard cold snaps, and eventually moisture ingress into the motor assembly from repeated freeze-thaw cycles. The damper starts leaking past its closed position, then stops sealing reliably. That failure pattern typically shows up in the second or third winter — long after installation, and after anyone would connect it to the damper specification.

The HAC-L insulates the damper body only. It does not replace duct insulation on the run from the exterior to the air handler. Insulate the duct run separately per code and application requirements. The HAC-L solves the damper-location condensation problem — insulating the duct run solves the duct-level problem. Both are required on a cold climate fresh air installation.

Why Factory Insulation — Not Field-Wrapping

Field-wrapping misses the thermal bridges that matter most.

Field-wrapping foam insulation around an installed damper seems complete until you look at what gets missed. The actuator housing, motor leads, end switch wiring penetrations, and the collar-to-duct joint all create gaps that foam tape doesn't close cleanly. Those gaps are exactly where condensation forms first — on cold metal surfaces where warm air contacts the uninsulated fastener, wire exit point, or edge of the tape wrap. Factory insulation is applied before assembly, covering those surfaces as part of the damper body geometry and sealing around the components that create thermal bridges.

HAC vs. HAC-L — One Question to Answer

Is the damper location subject to condensation or significant heat loss?

Choose HAC (standard) when…	Choose HAC-L when…
Damper is in conditioned mechanical space	Damper is in unconditioned or semi-conditioned space
No condensation risk at the damper location	Damper body will be exposed to cold exterior temperatures
Duct run is fully insulated to the damper location	Damper is near the exterior wall or in a cold zone
Southern climate or warm installation environment	Canadian climate or northern US — cold winters, freeze-thaw cycling
Standard residential or commercial install	HRV/ERV in an unheated mechanical room or crawlspace

When in doubt, specify the HAC-L. The cost difference over the standard HAC is modest. The callback cost of a failed damper in year two is not. If you're asking whether the location might have a condensation problem, it probably does.

Configuration Guide

Same options as the standard HAC — all factory-installed. PO/PC cannot be changed after installation.

Variant Code	Action	Relay	End Switch	Part Number Example (6")
OPO	Power Open	No relay	No	HAC-0610-OPO-L
SPO	Power Open	No relay	Yes	HAC-0610-SPO-L
OPO (relay)	Power Open	Relay included	No	HAC-0611-OPO-L
SPO (relay)	Power Open	Relay included	Yes	HAC-0611-SPO-L
OPC	Power Close	No relay	No	HAC-0610-OPC-L
SPC	Power Close	No relay	Yes	HAC-0610-SPC-L
OPC (relay)	Power Close	Relay included	No	HAC-0611-OPC-L
SPC (relay)	Power Close	Relay included	Yes	HAC-0611-SPC-L

Relay not available on 2" and 3" sizes. End switch is available on all sizes. PO and PC are not interchangeable — cannot be changed after installation. Confirm action before ordering.

Part Number Decoder

HAC-0611-SPO-L

HAC

Product family: universal inline air control damper

Size (2-digit): 02=2", 03=3", 04=4", 05=5", 06=6", 07=7", 08=8", 09=9"

10 / 11

Relay: 10 = no relay | 11 = relay included (not available on 2" and 3")

O / S

End switch: O = no end switch | S = end switch included

PO / PC

Action: PO = Power Open (spring-close fail-safe) | PC = Power Close (spring-open fail-safe)

-L

Insulated body suffix — confirms factory insulation on this unit

Key Specs

Sizes

2", 3", 4", 5", 6", 7", 8", 9"

Voltage

24 Vac

Insulation

Factory-applied before assembly

Drive

Patented Hoyme spring motor — stall-protected, nylon bearings

Action

PO or PC — specify at order

End Switch

Optional (S prefix) — all sizes

Relay

Optional (11 motor) — 4"–9" only

Certification

CSA certified — Canadian & US

Serviceability

Motor, microswitch, spring kits stocked

Warranty

2-yr electrical / 10-yr mechanical

Common Questions from the Counter

Answers to what comes up most when specifying the HAC-L.

When is the standard HAC sufficient — when does the job actually require the HAC-L?

The standard HAC is sufficient when the damper is in conditioned mechanical space where ambient temperature stays above the dewpoint of the indoor air year-round. The HAC-L is required when the damper location will be exposed to temperatures low enough to cause condensation on the metal body — typically any location in unconditioned space on a Canadian or northern US installation where outdoor temperatures regularly go below −10°C. When in doubt, specify the HAC-L. The cost difference is modest and the callback cost of a failed damper in year two is not.

Why not just field-wrap a standard HAC with foam insulation?

Field-wrapping looks complete but misses the thermal bridges that matter most — the actuator housing, motor lead exits, end switch wiring penetrations, and collar-to-duct joint edges. Those are cold metal surfaces where warm air contacts the uninsulated structure and condensation forms first. Factory insulation is applied before assembly, covering those surfaces as part of the product geometry. On a cold climate installation that will see twenty years of freeze-thaw cycling, factory insulation holds up. Field-wrapped foam tape delaminates, compresses, and gaps over time — usually at the worst locations. If a standard HAC is already installed and experiencing condensation issues, field-wrapping is better than nothing — but for new installations in cold locations, specify the HAC-L from the start.

Does the HAC-L replace duct insulation on the fresh air run?

No. The HAC-L insulates the damper body — the metal housing, blade assembly, and actuator mounting area. The duct run from the exterior penetration to the HAC-L is a separate duct section that still needs to be insulated per code and application requirements. The HAC-L solves the damper-level problem. Insulating the duct run solves the duct-level problem. Both are required on a cold climate fresh air installation.

Is there a 120 Vac version of the HAC-L?

Yes — the HAC-12L combines the 120 Vac built-in transformer with the factory-insulated body. Use HAC-12L when only 120 Vac is available at the damper location and insulation is required.

Are the end switch and relay available on the HAC-L?

Yes — the same options available on the standard HAC are available on the HAC-L: end switch (S prefix), relay (11 motor code), or both. The relay is not available on 2" and 3" sizes. Specify at order.

Ready to Order

HAC-L — Insulated Inline Fresh Air Damper

Select your size, action (PO/PC), end switch, and relay option — then add to cart. Confirm damper location is subject to condensation before ordering.

Configure & Order →

Size · Action · End Switch · Relay

Need help specifying the HAC-L?

Technical support available through your Hoyme wholesaler or direct.

1-800-661-7382

HAC-LInsulated InlineFresh Air Damper