This is the outdoor condenser (outdoor unit) only, Carrier model 37MAHAQ33AA3, for a single-zone ductless heat pump system. It's built for homeowners and installers who already have — or are separately sourcing — a matched Carrier indoor head, line set, and installation accessories; this listing does not include an indoor unit, line set, or mounting hardware.
The 37MAHAQ33AA3 is the outdoor half of a Carrier Infinity 27 single-zone ductless heat pump system, rated at 33,000 Btu/h cooling and 19.6 SEER2 with the matched indoor unit named in the AHRI-certified rating tables. This variable-speed (inverter-driven) outdoor unit uses Puron Advance™ (R-454B) refrigerant. Note: If you would like to review the manufacturer Product Specifications, Warranty, Brochure, etc., for this system, please refer to the "Resources (System Manuals and Warranty)" Tab above on this page.
System Components
- Outdoor condenser: Carrier 37MAHAQ33AA3 (family 37MAHA, size 33), variable-speed compressor, 208/230V;1Ph;60Hz
- Indoor unit: NOT included — must be purchased separately as a Carrier-matched indoor head (e.g., 615AHAQ33XA3 or 45MBAAQ36XB3 per AHRI-certified combinations in manufacturer documentation)
Installation Requirements & Accessories
- Voltage: 208/230V; 1 Phase; 60Hz — this outdoor unit is NOT compatible with 115V-only circuits
- Minimum Circuit Ampacity (MCA): 34A; Maximum Overcurrent Protection (MOP): 35A
- Refrigerant: R-454B (A2L classification), Puron Advance™, ESTER OIL lubricant
- Liquid line: 3/8 in (9.52mm); Suction line: 3/4 in (19mm)
- Line set is sold separately and is NOT included with this outdoor condenser
- Indoor unit, wall sleeve, mounting bracket, and line-hide kit are NOT included
- Professional installation by a licensed HVAC technician is required (R-454B refrigerant handling requires EPA Section 608 certification)
- Not a listed match for indoor unit families outside the AHRI-certified combinations published by Carrier for the 37MAHA outdoor series
Pro-Installer Tip
Flare connections on R-454B systems are unforgiving of shortcuts. A slightly under-torqued or scratched flare face is the most common source of slow refrigerant leaks and nuisance low-charge faults after startup. Left unaddressed, a marginal flare joint bleeds refrigerant over months, degrading capacity and eventually tripping a low-pressure or communication fault on the indoor board. Use a digital torque wrench set to the flare nut spec printed on the unit's nameplate or installation instructions, and re-torque only after visually confirming the flare surface is free of scoring. Because R-454B is an A2L mildly flammable refrigerant, this work falls under EPA Section 608 certification requirements — verify the installing technician holds the appropriate certification before startup.
Key Benefits
- Variable-speed (inverter-driven) compressor for closer temperature control than single-stage systems
- Outdoor sound pressure rated at 63 dBA at this size (33K)
- Heating output published down to 5°F outdoor ambient (DOE H42 test condition)
- Puron Advance™ (R-454B) refrigerant, lower global warming potential than legacy refrigerants per manufacturer data
- Ductless design simplifies retrofit installations compared to central ducted systems
Technical Table
| Spec | Value | Unit |
|---|---|---|
| Outdoor Model | 37MAHAQ33AA3 | — |
| Cooling Capacity (DOE A2 - 95°F) | 33000 | Btu/h |
| Heating Capacity (DOE H12 - 47°F) | 36000 | Btu/h |
| Heating Capacity (DOE H32 - 17°F) | 30000 | Btu/h |
| Heating Capacity (DOE H42 - 5°F) | 35000 | Btu/h |
| SEER2 | 19.6 | Btu/h.W |
| EER2 (DOE A2 - 95°F) | 12 | Btu/h.W |
| HSPF2 IV | 10.5 | Btu/h.W |
| HSPF2 V | 8.6 | Btu/h.W |
| Voltage / Phase / Frequency | 208/230;1;60 | V;Ph;Hz |
| MCA (Minimum Circuit Ampacity) | 34 | A |
| MOP (Maximum Overcurrent Protection) | 35 | A |
| Outdoor Sound Pressure Level | 63 | dBA |
| Net Weight | 156.97 | lbs |
| Refrigerant Type | R-454B | — |
| Liquid Pipe Size | 3/8 (9.52) | in (mm) |
| Suction Pipe Size | 3/4 (19) | in (mm) |
| Operating Range - Cooling | -22 to 122 (-30 to 55) | °F (°C) |
| Zone Count | 1 (Single-Zone) | — |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
- This is the outdoor condenser only — the indoor unit is sold separately and is required to complete the system
- AHRI-certified matched indoor units published by Carrier for the 37MAHAQ33AA3 include 615AHAQ33XA3 and 45MBAAQ36XB3, per the manufacturer's rating tables
- Requires a dedicated 208/230V single-phase circuit; NOT compatible with 115V-only circuits
- Line set NOT included; installer must supply 3/8 in liquid / 3/4 in suction line sized and routed per the matched indoor unit's manual
- Wall sleeve, mounting bracket, and line-hide kit are NOT included
- Not a listed match for indoor unit models outside Carrier's published AHRI combinations for the 37MAHA outdoor family
FAQ
What breaker size do I need for this system?
The 37MAHAQ33AA3 outdoor unit has a Minimum Circuit Ampacity (MCA) of 34A and a Maximum Overcurrent Protection (MOP) rating of 35A on a 208/230V, single-phase, 60Hz circuit. A licensed electrician should size the breaker and wire gauge to these values and local code.
Is professional installation required to keep the warranty valid, or is this a true DIY kit?
This is not a DIY kit. This outdoor unit uses R-454B refrigerant (A2L classification) and requires professional installation by a licensed HVAC technician. Consumer Choice Warranty terms are described in the manufacturer documentation.
Is the line set included, and if not, what size do I need to buy?
No line set is included with this outdoor unit. For the 37MAHAQ33AA3, the manufacturer specifies a 3/8 inch (9.52mm) liquid line and a 3/4 inch (19mm) suction line. Line set length and total pipe run must be verified against the matched indoor unit's installation manual.
Does this system work in cold climates (low-ambient heating)?
The 37MAHAQ33AA3 is rated for heating operation down to a published test condition of 5°F (DOE H42 test), producing 35000 Btu/h at that condition, and down to -22°F (-30°C) for the outdoor operating range published in cooling mode. Actual low-ambient heating performance depends on the matched indoor unit; refer to the manufacturer documentation for the specific pairing.
What indoor units is this outdoor condenser compatible with?
Carrier publishes AHRI-matched ratings for the 37MAHAQ33AA3 with specific indoor models, including 615AHAQ33XA3 and 45MBAAQ36XB3, at the capacities and efficiencies shown in the manufacturer documentation. This outdoor unit is not rated as a matched system with indoor models outside those published combinations. [NEEDS VERIFICATION] for any indoor model not explicitly listed in Carrier's published AHRI match tables.
Compliance & Warranty
Installation by a licensed HVAC professional is required to maintain warranty. This outdoor unit uses R-454B (A2L mildly flammable) refrigerant and must be installed and charged by an EPA Section 608 certified technician. Carrier's Consumer Choice Warranty offers, upon timely registration on eligible equipment, either a 10-year parts-only limited warranty or a 5-year parts plus 3-year labor limited warranty; refer to the manufacturer warranty documentation in the Resources tab for exact eligibility terms.
