This listing is the outdoor condenser (outdoor unit) only โ Carrier model 37MBRAQ48AA3, a 48K BTU single-zone heat pump condenser designed to pair with a matched Carrier indoor unit. It's built for installers and homeowners assembling a system for a single room or light commercial space where the outdoor unit needs replacing or the indoor head is purchased separately.
The Carrier Performance 20 outdoor unit is engineered for single-zone light commercial and residential applications, using an inverter-driven (variable-speed) compressor to hold steady temperature output rather than cycling on and off. It is AHRI-rated as a system when matched to a specific indoor unit โ the manufacturer's published rating table references this outdoor unit paired with a 45MBDA-series indoor unit. 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 (included in this listing): Carrier 37MBRAQ48AA3, 48K BTU/h nominal capacity, R-454B refrigerant, inverter-driven compressor, 208/230V single-phase power.
- Indoor Unit (NOT included): A matched Carrier indoor head, such as an appropriately sized unit from the 45MBDA family, must be purchased separately to complete the system.
Installation Requirements & Accessories
- Voltage: 208/230V; 1Ph; 60Hz. Not compatible with 115V-only circuits.
- Refrigerant: R-454B (A2L, mildly flammable) โ installation and servicing require EPA Section 608 certification.
- Line set: liquid line 3/8 in, suction line 3/4 in. Standard length 24.6 ft (7.5 m); total maximum piping length per system is 246 ft (75 m). Line set is sold separately.
- Power connection wiring: 14 AWG, 2 wire + Ground, per manufacturer wiring table.
- Not included: indoor unit, line set, wall sleeve, mounting bracket, disconnect, or refrigerant beyond the factory charge.
- Not compatible with 115V-only circuits.
- Professional installation required โ this is not a DIY pre-charged quick-connect system.
Pro-Installer Tip
Flare connections on R-454B systems demand the same discipline as any A2L refrigerant job: a loose or under-torqued flare nut is the single most common cause of slow leaks that show up months later as reduced capacity or nuisance fault codes. Pull the system down and verify a proper vacuum before charging, and torque every flare joint to the manufacturer's spec using a calibrated digital torque wrench rather than "feel" โ over-tightening cracks the flare face just as reliably as under-tightening leaks. This is EPA Section 608 territory: only a certified technician should handle R-454B recovery, evacuation, and charging, and documentation of the vacuum and charge weight protects both the warranty and the refrigerant charge amount (7.94 lb for this unit) called out on the nameplate.
Key Benefits
- Inverter-driven (variable-speed) compressor adjusts output to match load instead of cycling full-on/full-off.
- Outdoor sound pressure as low as 62.5 dB(A) at this size.
- Puron Advanceโข (R-454B) refrigerant reduces global warming potential by 75% versus older refrigerants per Carrier's published figures.
- Piping flexibility up to 246 ft (75 m) total system length supports longer indoor-to-outdoor runs.
- Crankcase heater standard on all unit sizes for reliable cold-weather compressor starts.
- Electronic expansion valve manages refrigerant flow to the connected indoor unit.
Technical Table
| Spec | Value | Unit |
|---|---|---|
| Model | 37MBRAQ48AA3 | โ |
| Component Role | Outdoor Condenser (Outdoor Unit Only) | โ |
| Cooling/Heating Capacity | 46744 | BTU/h |
| SEER2 | Up to 20 | SEER2 |
| HSPF2 | Up to 10.4 | HSPF2 |
| Power Supply | 208/230; 1; 60 | V; Ph; Hz |
| Refrigerant Type | R-454B | โ |
| Refrigerant Charge Amount | 7.94 (3.6) | lb (kg) |
| Liquid Pipe Size | 3/8 (9.52) | in (mm) |
| Suction Pipe Size | 3/4 (19) | in (mm) |
| Outdoor Sound Pressure | 62.5 | dB(A) |
| Operating Weight | 208.78 (94.7) | lb (kg) |
| Height | 52.5 (1333) | in (mm) |
| Width | 37.5 (952) | in (mm) |
| Depth | 16.3 (415) | in (mm) |
| Standard Piping Length | 24.6 (7.5) | ft (m) |
| Max Piping Length, No Added Refrigerant | 24.6 (7.5) | ft (m) |
| Total Maximum Piping Length | 246 (75) | ft (m) |
| Minimum Piping Length | 10 (3) | ft (m) |
| Outdoor Airflow | 4240.3 | CFM |
| Power Connection Wiring | 14 AWG, 2 wire + Ground | โ |
| Operating Range (Heating, per overview) | Down to -13 | ยฐF |
| Operating Range (Cooling, per overview) | Up to 122 | ยฐF |
| MCA / MOCP | [NEEDS VERIFICATION] | โ |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
- This outdoor unit is AHRI-matched, per manufacturer documentation, with a 45MBDA-series indoor unit at the 48K size โ confirm the exact matched model number in the manufacturer's engineering data under the Resources tab before ordering the indoor head.
- Operates on dedicated 208/230V, single-phase, 60Hz circuits only. Not compatible with 115V-only circuits.
- Indoor unit, line set, wall sleeve, mounting bracket, and disconnect switch are NOT included in this listing and must be purchased separately.
- Refrigerant is R-454B (A2L). This unit is not interchangeable with outdoor units designed for R-410A or R-32 systems without manufacturer-verified compatibility.
- Not a complete, ready-to-run system on its own โ this SKU is the outdoor condenser component only.
FAQ
What breaker size do I need for this system?
The manufacturer data provided does not list an MCA or MOCP value for the 48K (37MBRAQ48AA3) size. [NEEDS VERIFICATION] Consult the installation manual under the Resources tab for the correct breaker sizing before wiring this unit.
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 (an A2L mildly flammable refrigerant) and requires professional installation by a licensed HVAC technician to maintain the manufacturer warranty.
Is the line set included, and if not, what size do I need to buy?
The line set is sold separately. This outdoor unit requires a 3/8 inch liquid line and a 3/4 inch suction line. Standard piping length is 24.6 ft (7.5 m) with no additional refrigerant charge required up to that length; total maximum piping length per system is 246 ft (75 m), with additional refrigerant needed beyond the standard length.
Does this system work in cold climates (low-ambient heating)?
The manufacturer overview states this system is built to deliver heating capability in temperatures down to -13ยฐF and cooling capability in temperatures up to 122ยฐF. Confirm exact operating range figures against the installation manual under the Resources tab, as the detailed operating range table was not fully legible in the source data. [NEEDS VERIFICATION]
What indoor unit does this outdoor unit pair with?
The manufacturer documentation references a matched combination of 37MBRA (outdoor) with 45MBDA indoor units for AHRI-rated performance at this size. The specific indoor model number and its individual specs are not included in this listing and are sold separately.
Compliance & Warranty
Installation by a licensed HVAC professional is required to maintain warranty. This unit uses R-454B (A2L classification) refrigerant; handling, recovery, and charging must be performed by an EPA Section 608 certified technician. Per Carrier's Consumer Choice Warranty, upon timely registration on eligible equipment, buyers may select either a 10-year parts-only limited warranty or a 5-year parts plus 3-year labor limited warranty. Full warranty terms, eligibility, and registration requirements are in the manufacturer documentation under the "Resources (System Manuals and Warranty)" Tab above.
