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      48,000 BTU mini-split heat pump · 45M Series

      Carrier 37MBRAQ48AA3

      Below average cooling efficiency and average heating efficiency for a 48,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #85 of 146 48,000 BTU mini-splits for cooling efficiency, and costs about $1,285 a year to run in a mixed climate like Atlanta.

      SEER2
      19.9 Cooling efficiency over a season
      Below average · beats 14%
      HSPF2
      10.2 Heating efficiency over a season
      Average · beats 53%
      EER2
      9.5 Cooling efficiency on a 95°F day
      Below average · beats 3%
      Heat at 5°F
      40,500 BTU/h77% of its 47°F output
      Very good · beats 71%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 40,500 BTU/h at 5°F.
      • You want steady temperatures and quiet running - the compressor varies its speed.
      • You want a choice of indoor units - 20 certified pairings.

      Think twice if…

      • Cooling cost matters most - its SEER2 is below average for mini-splits.

      Calculate my running cost

      Details

      Specifications48,000 BTU, R-454B
      General
      BrandCarrier
      Also sold asBryant, Payne, WeatherMaker, Midea
      Outdoor unit model37MBRAQ48AA3
      Series45M Series
      TypeMini-split heat pump
      Nominal size48,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceNovember 15, 2018
      Last certifiedMarch 13, 2025
      Cooling
      SEER2Seasonal efficiency, higher is better19.9 (range 17.2-19.9)
      EER2Efficiency at 95°F outdoors9.5-10.0
      Cooling capacity48,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.8-10.2
      Capacity at 47°F50,000 BTU/h
      Capacity at 17°F36,600-40,000 BTU/h
      Capacity at 5°F35,200-40,500 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.90-2.11
      ENERGY STAR cold climateYes
      Heating output as it gets colder77% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with 45MCFAQ48XA3 at the standard test temperatures, in BTU/h:

      Certified matchups20 indoor units

      The same outdoor unit scores differently with each indoor unit. Ask your installer for the AHRI reference number of the exact system you are quoted.

      Indoor unitSEER2EER2HSPF2Heat @5°FAHRI ref.
      45MCFAQ48XA3 CARRIER · cold climate19.99.510.238,500215323854
      45MCFAQ48XA3 BRYANT · cold climate19.99.510.238,500215323915
      45MCFAQ48XA3 PAYNE · cold climate19.99.510.238,500215323976
      45MCFAQ48XA3 Weathermaker · cold climate19.99.510.238,500215324037
      45MCFAQ48XA3 MIDEA · cold climate19.99.510.238,500215324098
      45MBCAQ48XA3 CARRIER · cold climate19.19.59.940,500215323853
      45MBCAQ48XA3 BRYANT · cold climate19.19.59.940,500215323914
      45MBCAQ48XA3 PAYNE · cold climate19.19.59.940,500215323975
      45MBCAQ48XA3 Weathermaker · cold climate19.19.59.940,500215324036
      45MBCAQ48XA3 MIDEA · cold climate19.19.59.940,500215324097
      45MBAAQ48XA3 · cold climate17.810.010.035,200215318773
      45MBAAQ48XA3 · cold climate17.810.010.035,200215318801
      45MBAAQ48XA3 · cold climate17.810.010.035,200215318829
      45MBAAQ48XA3 · cold climate17.810.010.035,200215318857
      45MBAAQ48XA3 · cold climate17.810.010.035,200215318885
      45MBDAQ48XH3 CARRIER · cold climate17.210.09.838,000215323855
      45MBDAQ48XH3 BRYANT · cold climate17.210.09.838,000215323916
      45MBDAQ48XH3 PAYNE · cold climate17.210.09.838,000215323977
      45MBDAQ48XH3 Weathermaker · cold climate17.210.09.838,000215324038
      45MBDAQ48XH3 MIDEA · cold climate17.210.09.838,000215324099
      Yearly running cost in 10 large cities$1,134-$3,084

      At each state's average electricity price and the city's typical heating and cooling hours.

      Questions5
      What is the SEER2 rating of the Carrier 37MBRAQ48AA3?
      The Carrier 37MBRAQ48AA3 is rated at up to 19.9 SEER2 and 9.5 EER2 for cooling and up to 10.2 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 20 certified matchups SEER2 ranges from 17.2-19.9.
      Is the Carrier 37MBRAQ48AA3 good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 40,500 BTU/h at 5°F with a COP of 2.11, so it is still 2.1 times as efficient as electric resistance heat at that temperature.
      How much does the Carrier 37MBRAQ48AA3 cost to run per year?
      At its rated efficiency it costs about $1,134-$3,084 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,405 in Phoenix and $2,582 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
      Which indoor units work with the Carrier 37MBRAQ48AA3?
      ENERGY STAR lists 20 certified combinations for this outdoor unit. The highest-rated ones use CARRIER 45MCFAQ48XA3, BRYANT 45MCFAQ48XA3, PAYNE 45MCFAQ48XA3.
      What refrigerant does the Carrier 37MBRAQ48AA3 use?
      It uses R-454B.

      Running cost and savings

      Pre-filled with this model. Pick your city and what you heat with today; everything else is optional.

      Heat pump $1,398/yrYou save $1,110/yrSee details ↓
      1. Where you live
      Adjust heating and cooling hours

      Filled in from your city's climate. Change them if you run the system much more or less than usual.

      2. The heat pump Carrier 37MBRAQ48AA3
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $1,398
      Current system, per year
      $2,508
      You save per year
      $1,110
      Payback
      16.2 years
      Net after 10 years
      -$6,903

      Cooling $849Heating $549Electricity used: 8,738 kWhSaved vs. a minimum-efficiency heat pump: $530

      Estimates use the unit's rated SEER2 and HSPF2, full-load hours derived from NOAA 1991-2020 degree days, average residential electricity prices from the U.S. EIA (12 months to July 2026) and fuel prices from EIA (2025 for natural gas, week of 2026-10-05 for propane and heating oil). Very cold days that need backup heat are not modelled. Federal minimum for comparison: 14.3 SEER2 / 7.5 HSPF2.

      Similar 48,000 BTU models

      See all 146 48,000 BTU mini-splits, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of March 13, 2025. How we use the data.