This is the outdoor condenser unit for a Carrier Infinity 25 multi-zone mini split heat pump system. It's built for homeowners or installers assembling a ductless multi-zone setup — pairing this outdoor unit with up to six matched indoor heads (sold separately) to heat and cool multiple rooms without ductwork.
This outdoor condenser is part of Carrier's Infinity 25 Multi-Zone High-Heat lineup, engineered to pair with matched indoor heads for zoned comfort in homes without ductwork. Carrier publishes AHRI-rated system performance with a named indoor unit in the same rating row; the ratings below reflect the 55K (37MGHAQ55FA3) outdoor unit column only, not the family's "up to" maximum. 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 37MGHAQ55FA3, family 37MGHA, size 55K, variable-speed inverter-driven compressor, R-454B (Puron Advance) refrigerant.
- Indoor Units: NOT included. Supports up to six matched indoor heads (wall-mounted, cassette, ducted, or mixed) sold separately and selected to match total system capacity.
Installation Requirements & Accessories
- Voltage: 208/230V; 1Ph; 60Hz.
- Line set sold separately — liquid pipe 6x1/4in (5x6.35mm), suction pipe 4x3/8in+2x1/2in (4x9.52mm+2x12.7mm) at the size-55 outdoor connection point.
- Standard piping length per indoor unit: 24.6 ft. Minimum piping length per indoor unit: 10 ft. Total maximum piping length per system: 328 ft.
- Professional installation required. R-454B is an A2L mildly flammable refrigerant classification requiring licensed HVAC handling.
- Not included: indoor unit(s), wall sleeve/mounting bracket, line set, and grille.
- Not compatible with 115V-only circuits.
- Not a listed match for indoor unit families that are not AHRI-certified in combination with 37MGHAQ55FA3.
Pro-Installer Tip
Flare connections on R-454B systems are unforgiving of shortcuts — an under-torqued or scored flare seat leaks slowly, showing up months later as reduced capacity or a nuisance fault code rather than an immediate failure. Use a digital torque wrench set to the fitting manufacturer's spec and a proper flaring tool rather than eyeballing it by feel; this prevents refrigerant loss over the life of the system and protects the variable-speed compressor from operating outside its charge window. Evacuate the line set to the level called for in Carrier's installation instructions before charging — do not skip this step to save time. Because R-454B is an A2L refrigerant, EPA Section 608 certification is required to purchase refrigerant and legally perform this work, and correct evacuation practice directly supports the system's rated SEER2/HSPF2 efficiency numbers.
Key Benefits
- Variable-speed inverter compressor for steadier temperature control with fewer on/off cycles.
- Rated up to 20.2 SEER2 cooling and 10.5 HSPF2 heating efficiency at this size (per manufacturer data for 37MGHAQ55FA3).
- Retains 47,000 Btu/h heating capacity at 5°F outdoor ambient — suited to cold-climate installations.
- Outdoor sound pressure as low as 65 dBA at this size.
- Supports up to six indoor zones from a single outdoor unit for whole-home or multi-room zoning.
- Uses Puron Advance (R-454B) refrigerant, rated by the manufacturer as lower global warming potential than legacy refrigerants.
| Spec | Value | Unit |
|---|---|---|
| Model | 37MGHAQ55FA3 | — |
| Size Code | 55K | — |
| Cooling Rated Capacity (DOE A2, 95°F) | 51000 | Btu/h |
| Heating Rated Capacity (DOE H12, 47°F) | 55000 | Btu/h |
| Heating Maximum Capacity (5°F) | 47000 | Btu/h |
| SEER2 | 20.2 | — |
| HSPF2 (IV) | 10.5 | — |
| EER2 (DOE A2, 95°F) | 11.7 | Btu/h.W |
| Voltage | 208/230; 1; 60 | V;Ph;Hz |
| Refrigerant Type | R-454B | — |
| Outdoor Sound Pressure Level | 65 | dBA |
| Net Weight | 246.48 | lbs |
| Height | 52.48 | in |
| Width | 37.25 | in |
| Depth | 17.63 | in |
| Standard Piping Length per Indoor Unit | 24.6 | ft |
| Min Piping Length per Indoor Unit | 10 | ft |
| Total Max Piping Length per System | 328 | ft |
| Zone Count (Max) | 6 | indoor units |
| Breaker Size / MCA / MOCP | [NEEDS VERIFICATION] | — |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
- Compatible with 208/230V single-phase, 60Hz dedicated circuits only.
- Designed to pair with AHRI-certified Carrier indoor heads matched to the 37MGHA family — confirm the specific indoor model number(s) are listed as a certified match before ordering.
- Supports up to six indoor zones total; total connected indoor capacity and piping length must stay within the manufacturer's published system limits (max 328 ft total piping).
- NOT compatible with 115V-only circuits.
- NOT a listed match for indoor unit families outside Carrier's AHRI-certified combinations for 37MGHAQ55FA3.
- Line set, wall sleeve/mounting bracket, indoor unit(s), and grille are NOT included with this outdoor unit — all sold separately.
FAQ
What breaker size do I need for this system?
[NEEDS VERIFICATION] — the manufacturer data provided does not list a specific MCA or MOCP/breaker size for the 37MGHAQ55FA3 outdoor unit. Confirm with the manufacturer specification sheet before wiring.
Is professional installation required to keep the warranty valid, or is this a true DIY kit?
This is not a DIY kit. It uses R-454B refrigerant (an A2L mildly flammable classification) and requires professional installation by a licensed HVAC contractor.
Is the line set included, and if not, what size do I need to buy?
The line set is sold separately. For the 55K outdoor unit, the manufacturer data lists a liquid pipe size of 6x1/4in (5x6.35mm) and a suction pipe size of 4x3/8in+2x1/2in (4x9.52mm+2x12.7mm), depending on configuration. Confirm exact per-port sizing against your chosen indoor unit lineup.
Will the ceiling cassette fit between standard 16-inch on-center joists?
This listing is for the outdoor condenser only — no indoor cassette is included. Joist fitment depends on which indoor head model you pair with this outdoor unit; check that indoor unit's own listing for cassette architecture and joist clearance.
Does this system work in cold climates (low-ambient heating)?
Yes. The manufacturer data lists a Heating Maximum Capacity of 47,000 Btu/h at 5°F outdoor ambient for the 55K outdoor unit, indicating retained heating output in cold conditions.
Compliance & Warranty
Installation by a licensed HVAC professional is required to maintain warranty. This unit uses R-454B (A2L mildly flammable) refrigerant and must be installed per EPA Section 608 requirements. Carrier's Consumer Choice Warranty applies upon timely registration: eligible equipment qualifies for either a 10-year parts-only limited warranty, or a 5-year parts plus 3-year labor limited warranty, per manufacturer terms. Refer to the "Resources (System Manuals and Warranty)" Tab above for full warranty documentation.
