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      6,000 BTU mini-split heat pump · 45M Series

      Carrier 37MAHAQ06AA3

      Excellent cooling and heating efficiency for a 6,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #20 of 42 6,000 BTU mini-splits for cooling efficiency, and costs about $132 a year to run in a mixed climate like Atlanta.

      SEER2
      25.7 Cooling efficiency over a season
      Excellent · beats 90%
      HSPF2
      14.8 Heating efficiency over a season
      Excellent · beats 99%
      EER2
      18.0 Cooling efficiency on a 95°F day
      Excellent · beats 99%
      Heat at 5°F
      8,100 BTU/h110% of its 47°F output
      Excellent · beats 93%

      A good fit if…

      • You want low cooling bills - its SEER2 beats 90% of mini-splits.
      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 8,100 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 99% of mini-splits.
      • You want steady temperatures and quiet running - the compressor varies its speed.

      Think twice if…

      • Nothing stands out - its ratings have no weak spot for its class.

      Calculate my running cost

      Details

      Specifications6,000 BTU, R-454B
      General
      BrandCarrier
      Also sold asBryant, Payne, WeatherMaker, Midea
      Outdoor unit model37MAHAQ06AA3
      Series45M Series
      TypeMini-split heat pump
      Nominal size6,000 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 better25.7 (range 21.5-25.7)
      EER2Efficiency at 95°F outdoors14.5-18.0
      Cooling capacity6,000-6,500 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better12.0-14.8
      Capacity at 47°F7,000-8,000 BTU/h
      Capacity at 17°F7,000-8,700 BTU/h
      Capacity at 5°F7,700-8,100 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.39-2.40
      ENERGY STAR cold climateYes
      Heating output as it gets colder110% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with 45MAHAQ06XA3 at the standard test temperatures, in BTU/h:

      Certified matchups17 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.
      45MAHAQ06XA3 CARRIER · cold climate25.718.014.87,700215323742
      615AHAQ06XA3 BRYANT · cold climate25.718.014.87,700215323753
      D5MAHAQ06XA3 PAYNE · cold climate25.718.014.87,700215323764
      D5MAHAQ06XA3 Weathermaker · cold climate25.718.014.87,700215323775
      D5MAHAQ06XA3 MIDEA · cold climate25.718.014.87,700215323786
      D5MAHAQ06XA3 BRYANT · cold climate25.718.014.87,700218139562
      D5MAHAQ06XA3 CARRIER · cold climate25.718.014.87,700218139549
      45MCCAQ06XA3 CARRIER · cold climate22.015.212.08,100215323797
      45MCCAQ06XA3 BRYANT · cold climate22.015.212.08,100215323858
      45MCCAQ06XA3 PAYNE · cold climate22.015.212.08,100215323919
      45MCCAQ06XA3 Weathermaker · cold climate22.015.212.08,100215323980
      45MCCAQ06XA3 MIDEA · cold climate22.015.212.08,100215324041
      45MBDAQ06XA3 CARRIER · cold climate21.514.513.87,800215323798
      45MBDAQ06XA3 BRYANT · cold climate21.514.513.87,800215323859
      45MBDAQ06XA3 PAYNE · cold climate21.514.513.87,800215323920
      45MBDAQ06XA3 Weathermaker · cold climate21.514.513.87,800215323981
      45MBDAQ06XA3 MIDEA · cold climate21.514.513.87,800215324042
      Yearly running cost in 10 large cities$119-$316

      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 37MAHAQ06AA3?
      The Carrier 37MAHAQ06AA3 is rated at up to 25.7 SEER2 and 18.0 EER2 for cooling and up to 14.8 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 17 certified matchups SEER2 ranges from 21.5-25.7.
      Is the Carrier 37MAHAQ06AA3 good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 8,100 BTU/h at 5°F with a COP of 2.40, so it is still 2.4 times as efficient as electric resistance heat at that temperature.
      How much does the Carrier 37MAHAQ06AA3 cost to run per year?
      At its rated efficiency it costs about $119-$316 a year in electricity in large U.S. cities, depending on climate and local rates - for example $146 in Phoenix and $264 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 37MAHAQ06AA3?
      ENERGY STAR lists 17 certified combinations for this outdoor unit. The highest-rated ones use CARRIER 45MAHAQ06XA3, BRYANT 615AHAQ06XA3, PAYNE D5MAHAQ06XA3.
      What refrigerant does the Carrier 37MAHAQ06AA3 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 $145/yrYou save $205/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 37MAHAQ06AA3
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $145
      Current system, per year
      $350
      You save per year
      $205
      Payback
      12.2 years
      Net after 10 years
      -$451

      Cooling $89Heating $56Electricity used: 906 kWhSaved vs. a minimum-efficiency heat pump: $125

      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 6,000 BTU models

      See all 42 6,000 BTU mini-splits, ranked

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