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      12,000 BTU mini-split heat pump · M series

      Mitsubishi Electric SUZ-AA12NL

      Average cooling and heating efficiency for a 12,000 BTU mini-split heat pump, but not rated for cold climates.

      Ranks #315 of 394 12,000 BTU mini-splits for cooling efficiency, and costs about $357 a year to run in a mixed climate like Atlanta.

      SEER2
      21.7 Cooling efficiency over a season
      Average · beats 42%
      HSPF2
      10.0 Heating efficiency over a season
      Average · beats 43%
      EER2
      12.2 Cooling efficiency on a 95°F day
      Below average · beats 33%
      Heat at 5°F
      7,900 BTU/h52% of its 47°F output
      Very good · beats 86%

      A good fit if…

      • You want steady temperatures and quiet running - the compressor varies its speed.
      • You want a choice of indoor units - 12 certified pairings.

      Think twice if…

      • You often see nights below 0°F - it is not cold-climate certified.

      Calculate my running cost

      Details

      Specifications12,000 BTU, R-454B
      General
      BrandMitsubishi Electric
      Outdoor unit modelSUZ-AA12NL
      SeriesM series
      TypeMini-split heat pump
      Nominal size12,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceFebruary 3, 2025
      Last certifiedJune 13, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better21.7 (range 18.4-21.7)
      EER2Efficiency at 95°F outdoors11.8-12.6
      Cooling capacity11,300-12,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better8.7-10.0
      Capacity at 47°F12,000-15,000 BTU/h
      Capacity at 17°F9,600-9,800 BTU/h
      Capacity at 5°F7,700-7,900 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.00-2.30
      ENERGY STAR cold climateNo
      Heating output as it gets colder52% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with MSZ-EX12NLB at the standard test temperatures, in BTU/h:

      Certified matchups12 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.
      MSZ-EX12NLB21.712.210.07,800215748489
      MSZ-EX12NLW21.712.210.07,800215748493
      MSZ-EX12NLS21.712.210.07,800215748491
      MSZ-EX12NL2W21.712.210.07,800218597407
      MSZ-EX12NL2S21.712.210.07,800218597406
      MSZ-EX12NL2B21.712.210.07,800218597405
      MLZ-KX12NL20.711.810.07,700215734897
      SLZ-AF12NL20.312.59.77,900215734896
      PEAD-AA12NL19.712.59.77,800215734899
      MFZ-KX12NL19.612.68.77,800215734898
      SEZ-AD12NL19.012.19.67,800217232155
      SVZ-AP12NL18.412.19.77,800215734900
      Yearly running cost in 10 large cities$263-$899

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

      Questions5
      What is the SEER2 rating of the Mitsubishi Electric SUZ-AA12NL?
      The Mitsubishi Electric SUZ-AA12NL is rated at up to 21.7 SEER2 and 12.2 EER2 for cooling and up to 10.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 12 certified matchups SEER2 ranges from 18.4-21.7.
      Is the Mitsubishi Electric SUZ-AA12NL good for cold climates?
      It is not cold-climate certified: none of its matchups meet the ENERGY STAR cold-climate criteria (a COP of at least 1.75 at 5°F among other limits). In places with frequent sub-zero nights, pick a cold-climate 12,000 BTU model.
      How much does the Mitsubishi Electric SUZ-AA12NL cost to run per year?
      At its rated efficiency it costs about $263-$899 a year in electricity in large U.S. cities, depending on climate and local rates - for example $351 in Phoenix and $772 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 Mitsubishi Electric SUZ-AA12NL?
      ENERGY STAR lists 12 certified combinations for this outdoor unit. The highest-rated ones use MSZ-EX12NLB, MSZ-EX12NLW, MSZ-EX12NLS.
      What refrigerant does the Mitsubishi Electric SUZ-AA12NL 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 $363/yrYou save $305/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 Mitsubishi Electric SUZ-AA12NL
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $363
      Current system, per year
      $668
      You save per year
      $305
      Payback
      14.7 years
      Net after 10 years
      -$1,448

      Cooling $195Heating $168Electricity used: 2,267 kWhSaved vs. a minimum-efficiency heat pump: $157

      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 13, 2026. How we use the data.