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      18,000 BTU mini-split heat pump · NV-Series

      Trane / Mitsubishi Electric NTXSKH18A112AA

      Below average cooling and heating efficiency for a 18,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #435 of 465 18,000 BTU mini-splits for cooling efficiency, and costs about $573 a year to run in a mixed climate like Atlanta.

      SEER2
      19.2 Cooling efficiency over a season
      Below average · beats 11%
      HSPF2
      9.2 Heating efficiency over a season
      Below average · beats 16%
      EER2
      12.5 Cooling efficiency on a 95°F day
      Average · beats 44%
      Heat at 5°F
      21,600 BTU/h50% of its 47°F output
      Below average · beats 31%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 21,600 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.
      • You want the newest refrigerant - it uses R-410A, which is being phased down.

      Calculate my running cost

      Details

      Specifications18,000 BTU, R-410A
      General
      BrandTrane / Mitsubishi Electric
      Also sold asAmerican Standard / Mitsubishi Electric
      Outdoor unit modelNTXSKH18A112AA
      SeriesNV-Series
      TypeMini-split heat pump
      Nominal size18,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-410A
      Connected (smart) capableNo
      On the market sinceDecember 1, 2022
      Last certifiedJanuary 8, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better19.2 (range 18.7-19.2)
      EER2Efficiency at 95°F outdoors12.4-12.5
      Cooling capacity16,800-18,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better8.5-9.2
      Capacity at 47°F18,800-21,600 BTU/h
      Capacity at 17°F12,100-14,300 BTU/h
      Capacity at 5°F9,400-21,600 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.75-1.91
      ENERGY STAR cold climateYes
      Heating output as it gets colder50% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with SLZ-KF18NA at the standard test temperatures, in BTU/h:

      Certified matchups4 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.
      SLZ-KF18NA American Standard / Mitsubishi Electric19.212.58.59,400206331356
      NTXAMT18A112 · cold climate18.712.49.221,600211497093
      NTXAMT18A112AA · cold climate18.712.49.221,600204793353
      SVZ-KP18NA · cold climate18.712.49.221,600206331357
      Yearly running cost in 10 large cities$444-$1,425

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

      Questions5
      What is the SEER2 rating of the Trane / Mitsubishi Electric NTXSKH18A112AA?
      The Trane / Mitsubishi Electric NTXSKH18A112AA is rated at up to 19.2 SEER2 and 12.5 EER2 for cooling and up to 9.2 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 4 certified matchups SEER2 ranges from 18.7-19.2.
      Is the Trane / Mitsubishi Electric NTXSKH18A112AA good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 21,600 BTU/h at 5°F with a COP of 1.91, so it is still 1.9 times as efficient as electric resistance heat at that temperature.
      How much does the Trane / Mitsubishi Electric NTXSKH18A112AA cost to run per year?
      At its rated efficiency it costs about $444-$1,425 a year in electricity in large U.S. cities, depending on climate and local rates - for example $580 in Phoenix and $1,215 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 Trane / Mitsubishi Electric NTXSKH18A112AA?
      ENERGY STAR lists 4 certified combinations for this outdoor unit. The highest-rated ones use American Standard / Mitsubishi Electric SLZ-KF18NA, NTXAMT18A112, NTXAMT18A112AA.
      What refrigerant does the Trane / Mitsubishi Electric NTXSKH18A112AA use?
      It uses R-410A. R-410A is being phased down under the EPA AIM Act, and new systems are moving to R-454B and 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 $593/yrYou save $394/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 Trane / Mitsubishi Electric NTXSKH18A112AA
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $593
      Current system, per year
      $987
      You save per year
      $394
      Payback
      17.8 years
      Net after 10 years
      -$3,059

      Cooling $330Heating $263Electricity used: 3,706 kWhSaved vs. a minimum-efficiency heat pump: $173

      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 January 8, 2026. How we use the data.