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

      Mitsubishi Electric MUZ-FS12NA

      Excellent cooling efficiency and very good heating efficiency for a 12,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #31 of 394 12,000 BTU mini-splits for cooling efficiency, and costs about $273 a year to run in a mixed climate like Atlanta.

      SEER2
      26.3 Cooling efficiency over a season
      Excellent · beats 92%
      HSPF2
      11.1 Heating efficiency over a season
      Very good · beats 78%
      EER2
      13.8 Cooling efficiency on a 95°F day
      Very good · beats 79%
      Heat at 5°F
      14,700 BTU/h120% of its 47°F output
      Very good · beats 86%

      A good fit if…

      • You want low cooling bills - its SEER2 beats 92% of mini-splits.
      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 14,700 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 78% of mini-splits.
      • You want steady temperatures and quiet running - the compressor varies its speed.

      Think twice if…

      • You want the newest refrigerant - it uses R-410A, which is being phased down.

      Calculate my running cost

      Details

      Specifications12,000 BTU, R-410A
      General
      BrandMitsubishi Electric
      Also sold asAmerican Standard / Mitsubishi Electric, Trane / Mitsubishi Electric
      Outdoor unit modelMUZ-FS12NA
      SeriesM-Series
      TypeMini-split heat pump
      Nominal size12,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-410A
      Connected (smart) capableNo
      On the market sinceDecember 1, 2022
      Last certifiedMarch 13, 2025
      Cooling
      SEER2Seasonal efficiency, higher is better26.3 (range 26.3)
      EER2Efficiency at 95°F outdoors13.8
      Cooling capacity12,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better11.1
      Capacity at 47°F12,300 BTU/h
      Capacity at 17°F8,400 BTU/h
      Capacity at 5°F14,700 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.30
      ENERGY STAR cold climateYes
      Heating output as it gets colder120% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with MSZ-FS12NA 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.
      MSZ-FS12NA · cold climate26.313.811.114,700209832203
      NAXWPH12B112A American Standard / Mitsubishi Electric · cold climate26.313.811.114,700209832989
      NTXWPH12B112A Trane / Mitsubishi Electric · cold climate26.313.811.114,700209832990
      Same unit, other model numbers1

      These model numbers have exactly the same certified ratings and matchups as the Mitsubishi Electric MUZ-FS12NA: the same equipment under another brand, or a variant code for voltage, colour or market. Everything on this page applies to them.

      Yearly running cost in 10 large cities$216-$676

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

      Questions6
      What is the SEER2 rating of the Mitsubishi Electric MUZ-FS12NA?
      The Mitsubishi Electric MUZ-FS12NA is rated at up to 26.3 SEER2 and 13.8 EER2 for cooling and up to 11.1 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the Mitsubishi Electric MUZ-FS12NA good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 14,700 BTU/h at 5°F with a COP of 2.30, so it is still 2.3 times as efficient as electric resistance heat at that temperature.
      How much does the Mitsubishi Electric MUZ-FS12NA cost to run per year?
      At its rated efficiency it costs about $216-$676 a year in electricity in large U.S. cities, depending on climate and local rates - for example $280 in Phoenix and $575 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
      Is the Mitsubishi Electric MUZ-FS12NA the same as the Trane / Mitsubishi Electric NTXSPH12B112A?
      Yes, as far as the certified ratings go. ENERGY STAR lists both model numbers with identical efficiency, capacity and matchups, which means the same outdoor unit sold under a different brand or with a minor variant code (voltage, colour or region). The full list is on this page.
      Which indoor units work with the Mitsubishi Electric MUZ-FS12NA?
      ENERGY STAR lists 3 certified combinations for this outdoor unit. The highest-rated ones use MSZ-FS12NA, American Standard / Mitsubishi Electric NAXWPH12B112A, Trane / Mitsubishi Electric NTXWPH12B112A.
      What refrigerant does the Mitsubishi Electric MUZ-FS12NA 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 $285/yrYou save $339/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 MUZ-FS12NA
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $285
      Current system, per year
      $624
      You save per year
      $339
      Payback
      13.3 years
      Net after 10 years
      -$1,111

      Cooling $161Heating $124Electricity used: 1,779 kWhSaved vs. a minimum-efficiency heat pump: $194

      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 March 13, 2025. How we use the data.