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      3-ton central heat pump · 45M Series

      Carrier 37MUHAQ36AA3

      Average cooling efficiency and excellent heating efficiency for a 3-ton central heat pump, and certified for cold climates.

      Ranks #87 of 302 3 ton central heat pumps for cooling efficiency, and costs about $987 a year to run in a mixed climate like Atlanta.

      SEER2
      18.0 Cooling efficiency over a season
      Average · beats 66%
      HSPF2
      10.3 Heating efficiency over a season
      Excellent · beats 92%
      EER2
      12.0 Cooling efficiency on a 95°F day
      Average · beats 64%
      Heat at 5°F
      39,000 BTU/h101% of its 47°F output
      Below average · beats 20%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 39,000 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 92% of central heat pumps.
      • You want steady temperatures and quiet running - the compressor varies its speed.
      • You want a choice of indoor units - 38 certified pairings.

      Think twice if…

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

      Calculate my running cost

      Details

      Specifications3 ton, R-454B
      General
      BrandCarrier
      Also sold asBryant, Midea, WeatherMaker, Payne
      Outdoor unit model37MUHAQ36AA3
      Series45M Series
      TypeCentral heat pump
      Nominal size3 ton
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceNovember 15, 2018
      Last certifiedSeptember 22, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better18.0 (range 15.8-18.0)
      EER2Efficiency at 95°F outdoors10.7-12.0
      Cooling capacity36,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.4-10.3
      Capacity at 47°F37,000-38,000 BTU/h
      Capacity at 17°F29,200-33,000 BTU/h
      Capacity at 5°F34,600-39,000 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.80-1.90
      ENERGY STAR cold climateYes
      Heating output as it gets colder101% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with 45MUHAQ36XX3 at the standard test temperatures, in BTU/h:

      Certified matchups38 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.
      45MUHAQ36XX3 · cold climate18.012.010.037,400215323720
      45MUHAQ36XX3 · cold climate18.012.010.037,400215323721
      45MUHAQ36XX3 · cold climate18.012.010.037,400215323722
      45MUHAQ36XX3 · cold climate18.012.010.037,400215323723
      45MUHAQ36XX3 · cold climate18.012.010.037,400215323724
      D5FUHAH36XAK · cold climate18.012.010.037,400217557346
      D5FUHAH36XAK · cold climate18.012.010.037,400217557337
      D5FUHAH36XAK · cold climate18.012.010.037,400217730696
      D5FUHAH36XAK · cold climate18.012.010.037,400217730702
      D5FUHAH36XAK · cold climate18.012.010.037,400217730708
      45MUAAQ36XX3 · cold climate17.411.710.339,000215318751
      45MUAAQ36XX3 · cold climate17.411.710.339,000215318779
      45MUAAQ36XX3 · cold climate17.411.710.339,000215318807
      45MUAAQ36XX3 · cold climate17.411.710.339,000215318863
      45MUAAQ36XX3 · cold climate17.411.710.339,000215318835
      D5MUWAQ36XA3 · cold climate16.811.29.634,600217730619
      D5MUWAQ36XA3 · cold climate16.811.29.634,600217730635
      D5MUWAQ36XA3 · cold climate16.811.29.634,600217730651
      D5MUWAQ36XA3 · cold climate16.811.29.634,600217730667
      D5MUWAQ36XA3 · cold climate16.811.29.634,600217730683
      45MULAQ36XBX · cold climate15.810.79.436,000217456388
      45MULAQ36XBX · cold climate15.810.79.436,000217456304
      45MULAQ36XCX · cold climate15.810.79.436,000217456305
      45MULAQ36XBX · cold climate15.810.79.436,000217456332
      45MULAQ36XCX · cold climate15.810.79.436,000217456333
      45MULAQ36XBX · cold climate15.810.79.436,000217456360
      45MULAQ36XCX · cold climate15.810.79.436,000217456361
      45MULAQ36XCX · cold climate15.810.79.436,000217456389
      45MULAQ36XBX · cold climate15.810.79.436,000217456416
      45MULAQ36XCX · cold climate15.810.79.436,000217456417
      45MULBQ36XBX · cold climate15.810.79.436,000218792385
      45MULBQ36XCX · cold climate15.810.79.436,000218792384
      45MULBQ36XBX · cold climate15.810.79.436,000218792371
      45MULBQ36XCX · cold climate15.810.79.436,000218792370
      45MULBQ36XBX · cold climate15.810.79.436,000218792357
      45MULBQ36XCX · cold climate15.810.79.436,000218792356
      45MULBQ36XBX · cold climate15.810.79.436,000218792343
      45MULBQ36XCX · cold climate15.810.79.436,000218792342
      Yearly running cost in 10 large cities$937-$2,316

      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 37MUHAQ36AA3?
      The Carrier 37MUHAQ36AA3 is rated at up to 18.0 SEER2 and 12.0 EER2 for cooling and up to 10.3 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 38 certified matchups SEER2 ranges from 15.8-18.0.
      Is the Carrier 37MUHAQ36AA3 good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 39,000 BTU/h at 5°F with a COP of 1.90, so it is still 1.9 times as efficient as electric resistance heat at that temperature.
      How much does the Carrier 37MUHAQ36AA3 cost to run per year?
      At its rated efficiency it costs about $937-$2,316 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,129 in Phoenix and $1,915 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 37MUHAQ36AA3?
      ENERGY STAR lists 38 certified combinations for this outdoor unit. The highest-rated ones use 45MUHAQ36XX3, D5FUHAH36XAK, 45MUAAQ36XX3.
      What refrigerant does the Carrier 37MUHAQ36AA3 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 $1,106/yrYou save $766/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 37MUHAQ36AA3
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $1,106
      Current system, per year
      $1,873
      You save per year
      $766
      Payback
      17.6 years
      Net after 10 years
      -$5,837

      Cooling $704Heating $402Electricity used: 6,915 kWhSaved vs. a minimum-efficiency heat pump: $332

      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 3 ton models

      See all 302 3 ton central heat pumps, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of September 22, 2026. How we use the data.