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      12,000 BTU mini-split heat pump · Charmo

      GREE GWH12ATCXB-A6DNA1A/O

      Below average cooling and heating efficiency for a 12,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #379 of 394 12,000 BTU mini-splits for cooling efficiency, and costs about $358 a year to run in a mixed climate like Atlanta.

      SEER2
      19.0 Cooling efficiency over a season
      Below average · beats 9%
      HSPF2
      8.5 Heating efficiency over a season
      Below average · beats 2%
      EER2
      9.3 Cooling efficiency on a 95°F day
      Below average · beats 2%
      Heat at 5°F
      8,500 BTU/h71% of its 47°F output
      Below average · beats 9%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 8,500 BTU/h at 5°F.
      • You want steady temperatures and quiet running - the compressor varies its speed.

      Think twice if…

      • Cooling cost matters most - its SEER2 is below average for mini-splits.
      • You mainly need heat - its HSPF2 is below average for mini-splits.

      Calculate my running cost

      Details

      Specifications12,000 BTU, R-32
      General
      BrandGREE
      Outdoor unit modelGWH12ATCXB-A6DNA1A/O
      SeriesCharmo
      TypeMini-split heat pump
      Nominal size12,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-32
      Connected (smart) capableNo
      On the market sinceMay 19, 2026
      Last certifiedJune 9, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better19.0 (range 19.0)
      EER2Efficiency at 95°F outdoors9.3
      Cooling capacity12,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better8.5
      Capacity at 47°F12,000 BTU/h
      Capacity at 17°F9,700 BTU/h
      Capacity at 5°F8,500 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.80
      ENERGY STAR cold climateYes
      Heating output as it gets colder71% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with GWH12AZCXB-A6DN***/I at the standard test temperatures, in BTU/h:

      Certified matchups3 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.
      GWH12AZCXB-A6DN***/I · cold climate19.09.38.58,500217497274
      GWH12AWCXB-A6DN***/I · cold climate19.09.38.58,500215685135
      GWH12ATCXB-A6DN***/I · cold climate19.09.38.58,500214640136
      Yearly running cost in 10 large cities$298-$873

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

      Questions5
      What is the SEER2 rating of the GREE GWH12ATCXB-A6DNA1A/O?
      The GREE GWH12ATCXB-A6DNA1A/O is rated at up to 19.0 SEER2 and 9.3 EER2 for cooling and up to 8.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the GREE GWH12ATCXB-A6DNA1A/O good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 8,500 BTU/h at 5°F with a COP of 1.80, so it is still 1.8 times as efficient as electric resistance heat at that temperature.
      How much does the GREE GWH12ATCXB-A6DNA1A/O cost to run per year?
      At its rated efficiency it costs about $298-$873 a year in electricity in large U.S. cities, depending on climate and local rates - for example $378 in Phoenix and $737 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 GREE GWH12ATCXB-A6DNA1A/O?
      ENERGY STAR lists 3 certified combinations for this outdoor unit. The highest-rated ones use GWH12AZCXB-A6DN***/I, GWH12AWCXB-A6DN***/I, GWH12ATCXB-A6DN***/I.
      What refrigerant does the GREE GWH12ATCXB-A6DNA1A/O use?
      It uses R-32.

      Running cost and savings

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

      Heat pump $380/yrYou save $238/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 GREE GWH12ATCXB-A6DNA1A/O
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $380
      Current system, per year
      $619
      You save per year
      $238
      Payback
      18.9 years
      Net after 10 years
      -$2,117

      Cooling $222Heating $158Electricity used: 2,378 kWhSaved vs. a minimum-efficiency heat pump: $94

      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.

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      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of June 9, 2026. How we use the data.