HAC INLINE DAMPER · BELIMO TFB24 · ON/OFF SPRING RETURN · 24 VAC/DC · 6"–20"
Hoyme Damper Body. Belimo TFB24 Actuator. The Specified Choice When the Project Calls for Belimo.
The HAC-40 pairs Hoyme's CSA-certified inline damper body with the Belimo TFB24 — the most widely specified 24 Vac/dc on/off spring return actuator in commercial and light commercial HVAC. Factory-assembled, single SKU, complete certification documentation to 12". Sizes 6"–20" in even-inch increments.
Right product if:
On/off spring return control, sizes 6"–20", project specifies Belimo TFB24, or 24 Vac/dc supply flexibility is required.
Not this product if:
Modulating 2–10 VDC → HAC-43 · Floating point DDC → HAC-34 · Fire & smoke → HAC-90 · Line voltage → HAC-44
At a Glance
Actuator
Belimo TFB24 — on/off spring return
Voltage
24 Vac or 24 Vdc — either polarity on DC
Sizes
6", 8", 10", 12", 14", 16", 18", 20"
CSA Status
Certified to 12" — confirm AHJ for 14"–20"
Warranty
2-year electrical · 10-year mechanical
What the HAC-40 Is — and When to Use It
The TFB24 is a 2-position actuator: fully open or fully closed — no intermediate positioning. When the control signal is applied, the blade drives to the fully open (PO) or fully closed (PC) position. When the signal is removed, the spring return drives the blade to the opposite fail-safe position. On power loss, the blade moves to the fail-safe position regardless of what the control system is doing.
This is the correct control type for fresh air intakes, make-up air, zone dampers, and exhaust control — applications that require a gate: open when ventilation is called, closed when it isn't. If the application needs the blade positioned anywhere between open and closed — demand-controlled ventilation tracking CO₂, mixed air temperature control, building pressure management — see the HAC-43 (TFB24-SR-T modulating) instead.
Why Hoyme body + Belimo TFB24 as a factory assembly
When a project specifies a Belimo actuator, the HAC-40 gives you the TFB24 on a Hoyme CSA-certified Canadian-made damper body — factory-assembled, one SKU, one box, complete certification documentation. No field mounting, no actuator-to-damper compatibility questions, no separate certification paperwork for two components. For contractors working with Hoyme wholesalers, this is typically the faster path than sourcing a Belimo-branded assembly when the damper body brand isn't specified.
24 Vac or 24 Vdc — either polarity on DC
The TFB24 accepts 24 Vac or 24 Vdc at either polarity on the DC side. Most on/off spring return actuators at this price point are AC only. The TFB24's dual voltage acceptance is a practical advantage on BAS systems where the control output is 24 Vdc rather than 24 Vac.
Is On/Off the Right Control Type for Your Application?
| If you need… | Control type | Product |
|---|---|---|
| Full open or full closed — 2-position gate | On/off spring return | HAC-40 (TFB24) — this product |
| Proportional 0–100% via 2–10 VDC analog | Modulating spring return | HAC-43 (TFB24-SR-T) |
| 3-wire open/stop/close from DDC | Floating point | HAC-34 (CMB24-3-T) |
| UL 555S smoke damper listing required | Spring return + fire/smoke rated | HAC-90 (FSLF24 US) |
| Same on/off function — 100–240 Vac line voltage | On/off spring return, line voltage | HAC-44 (TFB120) |
PO vs. PC — Confirm Before Ordering
PO — Power Open STANDARD
Opens when signal applied. Spring-closes on power loss — duct seals.
Fresh air intake, make-up air, zone control — standard for all ventilation applications.
PC — Power Close
Closes when signal applied. Spring-opens on power loss — duct stays open.
Applications requiring fail-open on power loss.
PO and PC are not interchangeable and cannot be changed after installation. Confirm the required action before ordering.
Configuration Guide
Every HAC-40 uses the same Belimo TFB24 actuator. Select size, action, end switch, and heat bypass. That's all.
Select size — even-inch sizes 6"–20" only
6", 8", 10", 12", 14", 16", 18", 20". Odd sizes not available in this series. CSA certified to 12" — confirm AHJ acceptance for 14"–20" on code-required applications before ordering.
Select action — PO or PC
PO for fresh air intake, make-up air, zone control. PC if fail-open on power loss is required. Cannot be changed after installation — confirm before ordering.
End switch — optional (S prefix)
Add end switch (S prefix) if the BAS or controller needs blade position confirmation. No relay available on the TFB24 motor code — use a separate relay in the control circuit if needed.
Heat bypass — -H suffix, hot air zone control only
Adds a 10% bypass blade for single-speed furnace zone control where full shutoff causes static pressure spikes or high-limit trips. Factory-machined into the blade — permanent, not field-adjustable.
Do not specify -H on fresh air intake, make-up air, or ventilation applications. The bypass allows continuous outdoor air infiltration when the damper is commanded closed.
Variant and Part Number Reference
| Variant | Action | Heat bypass | End switch | Example (10") |
|---|---|---|---|---|
| OPO | Power Open | No bypass | No end switch | HAC-1040-OPO |
| OPO-H | Power Open | 10% bypass | No end switch | HAC-1040-OPO-H |
| SPO | Power Open | No bypass | Included | HAC-1040-SPO |
| SPO-H | Power Open | 10% bypass | Included | HAC-1040-SPO-H |
| OPC | Power Close | No bypass | No end switch | HAC-1040-OPC |
| OPC-H | Power Close | 10% bypass | No end switch | HAC-1040-OPC-H |
| SPC | Power Close | No bypass | Included | HAC-1040-SPC |
| SPC-H | Power Close | 10% bypass | Included | HAC-1040-SPC-H |
HOW TO READ YOUR PART NUMBER
Product
Size (10")
Belimo TFB24
End switch
Power Open
Heat bypass (opt.)
SIZE CODES
06=6" · 08=8" · 10=10" · 12=12" · 14=14" · 16=16" · 18=18" · 20=20"
MOTOR CODE
40 = Belimo TFB24, on/off spring return, 24 Vac/dc
END SWITCH PREFIX
O = no end switch · S = end switch included
ACTION + SUFFIX
PO = Power Open · PC = Power Close · -H = heat bypass
Key Specs
| Sizes | 6", 8", 10", 12", 14", 16", 18", 20" — even sizes only |
| Actuator | Belimo TFB24 — on/off spring return, 24 Vac/dc |
| Supply voltage | 24 Vac or 24 Vdc — either polarity on DC |
| Action | PO or PC — specify at order; cannot be changed after installation |
| End switch | Optional (S prefix) — confirms blade position |
| Relay | Not available on TFB24 motor code — use separate relay in control circuit if needed |
| Heat bypass | Optional (-H suffix) — 10% bypass, factory-set, not field-adjustable; hot air zone control only |
| CSA status | Certified to 12" — confirm AHJ acceptance for 14"–20" on code-required applications |
| Warranty | 2-year electrical · 10-year mechanical |
Common Questions
Why use the HAC-40 instead of a Belimo-branded damper assembly?
The HAC-40 gives you the TFB24 actuator on a Hoyme CSA-certified Canadian-made damper body — factory-assembled, single SKU, complete certification documentation. For contractors working with Hoyme wholesalers, this is typically the faster path when the project requires a TFB24 but the damper brand isn't specified.
What's the difference between the TFB24 and the TFB24-SR-T?
The TFB24 is an on/off actuator — fully open or fully closed, 2-position. The TFB24-SR-T is a modulating actuator that accepts a 2–10 VDC analog signal and positions the blade proportionally anywhere between open and closed. Use the TFB24 (HAC-40) when the application needs a gate. Use the TFB24-SR-T (HAC-43) when variable blade positioning is required.
Can I replace just the TFB24 actuator if it fails?
Yes — the Belimo TFB24 is field-replaceable. It mounts to the HAC damper body and can be removed and replaced without disturbing the damper body or duct connections. Replacement TFB24 actuators are widely stocked through Belimo distributors.
Does the TFB24 accept DC as well as AC?
Yes — the TFB24 accepts 24 Vac or 24 Vdc at either polarity on the DC side. Most on/off spring return actuators at this price point are AC only. The dual voltage acceptance is a practical advantage on BAS systems where the control output is 24 Vdc rather than 24 Vac.
Is the HAC-40 CSA certified for all sizes to 20"?
CSA certification is confirmed to 12". For 14"–20", confirm AHJ acceptance before ordering on code-required applications. Many commercial applications in this size range do not require CSA certification on individual HVAC components — confirm the requirement with the mechanical engineer and AHJ for the specific project before ordering.
Is the heat bypass available on all sizes?
Yes — the -H heat bypass is available on all HAC-40 sizes from 6" through 20". Specify -H only on hot air supply duct zone control applications where full shutoff causes heat buildup on a single-speed furnace. Do not specify -H on fresh air, make-up air, or ventilation applications — the bypass allows continuous outdoor air infiltration when the damper is commanded closed.
Related Products
Belimo TFB24-SR-T — modulating 2–10 VDC spring return on HAC body — for proportional blade positioning
Belimo TFB120 — same on/off spring return at 100–240 Vac line voltage
Belimo CMB24-3-T — 3-wire floating point, 24 Vac/dc — for DDC open/stop/close control
Belimo FSLF24 US — UL 555S listed fire and smoke actuator on HAC body