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      24,000 BTU mini-split heat pump · 45M Series

      Carrier 37MAHAQ24AA3

      Below average cooling efficiency and excellent heating efficiency for a 24,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #254 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $536 a year to run in a mixed climate like Atlanta.

      SEER2
      21.2 Cooling efficiency over a season
      Below average · beats 35%
      HSPF2
      13.5 Heating efficiency over a season
      Excellent · beats 96%
      EER2
      13.0 Cooling efficiency on a 95°F day
      Average · beats 62%
      Heat at 5°F
      24,200 BTU/h83% of its 47°F output
      Very good · beats 89%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 24,200 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 96% of mini-splits.
      • You want steady temperatures and quiet running - the compressor varies its speed.
      • You want a choice of indoor units - 27 certified pairings.

      Think twice if…

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

      Calculate my running cost

      Details

      Specifications24,000 BTU, R-454B
      General
      BrandCarrier
      Also sold asBryant, Payne, WeatherMaker, Midea
      Outdoor unit model37MAHAQ24AA3
      Series45M Series
      TypeMini-split heat pump
      Nominal size24,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceNovember 15, 2018
      Last certifiedJune 1, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better21.2 (range 18.8-21.2)
      EER2Efficiency at 95°F outdoors12.0-13.0
      Cooling capacity22,000-24,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better10.0-13.5
      Capacity at 47°F25,000-29,000 BTU/h
      Capacity at 17°F16,900-22,200 BTU/h
      Capacity at 5°F23,600-24,200 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.16-2.34
      ENERGY STAR cold climateYes
      Heating output as it gets colder83% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with 45MAHAQ24XA3 at the standard test temperatures, in BTU/h:

      Certified matchups27 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.
      45MAHAQ24XA3 CARRIER · cold climate21.213.013.524,200215323746
      615AHAQ24XA3 BRYANT · cold climate21.213.013.524,200215323757
      D5MAHAQ24XA3 PAYNE · cold climate21.213.013.524,200215323768
      D5MAHAQ24XA3 Weathermaker · cold climate21.213.013.524,200215323779
      D5MAHAQ24XA3 MIDEA · cold climate21.213.013.524,200215323790
      D5MAHAQ24XA3 BRYANT · cold climate21.213.013.524,200218139566
      D5MAHAQ24XA3 CARRIER · cold climate21.213.013.524,200218139553
      45MBCAQ24XA3 CARRIER · cold climate20.812.011.623,800215323815
      45MBCAQ24XA3 BRYANT · cold climate20.812.011.623,800215323876
      45MBCAQ24XA3 PAYNE · cold climate20.812.011.623,800215323937
      45MBCAQ24XA3 Weathermaker · cold climate20.812.011.623,800215323998
      45MBCAQ24XA3 MIDEA · cold climate20.812.011.623,800215324059
      45MCFAQ24XA3 CARRIER · cold climate20.512.012.124,200215323816
      45MCFAQ24XA3 BRYANT · cold climate20.512.012.124,200215323877
      45MCFAQ24XA3 PAYNE · cold climate20.512.012.124,200215323938
      45MCFAQ24XA3 Weathermaker · cold climate20.512.012.124,200215323999
      45MCFAQ24XA3 MIDEA · cold climate20.512.012.124,200215324060
      45MBDAQ24XH3 CARRIER · cold climate19.212.011.724,000215323817
      45MBDAQ24XH3 BRYANT · cold climate19.212.011.724,000215323878
      45MBDAQ24XH3 PAYNE · cold climate19.212.011.724,000215323939
      45MBDAQ24XH3 Weathermaker · cold climate19.212.011.724,000215324000
      45MBDAQ24XH3 MIDEA · cold climate19.212.011.724,000215324061
      45MBAAQ24XB3 · cold climate18.812.010.023,600215318765
      45MBAAQ24XB3 · cold climate18.812.010.023,600215318793
      45MBAAQ24XB3 · cold climate18.812.010.023,600215318849
      45MBAAQ24XB3 · cold climate18.812.010.023,600215318877
      45MBAAQ24XB3 · cold climate18.812.010.023,600215318821
      Yearly running cost in 10 large cities$509-$1,249

      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 37MAHAQ24AA3?
      The Carrier 37MAHAQ24AA3 is rated at up to 21.2 SEER2 and 13.0 EER2 for cooling and up to 13.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 27 certified matchups SEER2 ranges from 18.8-21.2.
      Is the Carrier 37MAHAQ24AA3 good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 24,200 BTU/h at 5°F with a COP of 2.34, so it is still 2.3 times as efficient as electric resistance heat at that temperature.
      How much does the Carrier 37MAHAQ24AA3 cost to run per year?
      At its rated efficiency it costs about $509-$1,249 a year in electricity in large U.S. cities, depending on climate and local rates - for example $619 in Phoenix and $1,030 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 37MAHAQ24AA3?
      ENERGY STAR lists 27 certified combinations for this outdoor unit. The highest-rated ones use CARRIER 45MAHAQ24XA3, BRYANT 615AHAQ24XA3, PAYNE D5MAHAQ24XA3.
      What refrigerant does the Carrier 37MAHAQ24AA3 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 $604/yrYou save $645/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 37MAHAQ24AA3
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $604
      Current system, per year
      $1,249
      You save per year
      $645
      Payback
      14.0 years
      Net after 10 years
      -$2,551

      Cooling $389Heating $216Electricity used: 3,776 kWhSaved vs. a minimum-efficiency heat pump: $360

      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 24,000 BTU models

      See all 430 24,000 BTU mini-splits, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of June 1, 2026. How we use the data.