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

      Fujitsu AOUH18LMAS1

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

      Ranks #311 of 465 18,000 BTU mini-splits for cooling efficiency, and costs about $427 a year to run in a mixed climate like Atlanta.

      SEER2
      21.1 Cooling efficiency over a season
      Below average · beats 34%
      HSPF2
      11.5 Heating efficiency over a season
      Very good · beats 84%
      EER2
      13.0 Cooling efficiency on a 95°F day
      Average · beats 62%
      Heat at 5°F
      21,600 BTU/h120% of its 47°F output
      Average · beats 48%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 21,600 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 84% of mini-splits.
      • 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 want the newest refrigerant - it uses R-410A, which is being phased down.

      Calculate my running cost

      Details

      Specifications18,000 BTU, R-410A
      General
      BrandFujitsu
      Outdoor unit modelAOUH18LMAS1
      SeriesH-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 sinceJune 24, 2021
      Last certifiedJune 5, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better21.1 (range 21.1)
      EER2Efficiency at 95°F outdoors13.0
      Cooling capacity18,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better11.5
      Capacity at 47°F18,000 BTU/h
      Capacity at 17°F13,600 BTU/h
      Capacity at 5°F21,600 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.00
      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 ASUH18LMAS at the standard test temperatures, in BTU/h:

      Certified matchups1 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.
      ASUH18LMAS FUJITSU · cold climate21.113.011.521,600206913027
      Yearly running cost in 10 large cities$400-$1,005

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

      Questions5
      What is the SEER2 rating of the Fujitsu AOUH18LMAS1?
      The Fujitsu AOUH18LMAS1 is rated at up to 21.1 SEER2 and 13.0 EER2 for cooling and up to 11.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the Fujitsu AOUH18LMAS1 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 2.00, so it is still 2.0 times as efficient as electric resistance heat at that temperature.
      How much does the Fujitsu AOUH18LMAS1 cost to run per year?
      At its rated efficiency it costs about $400-$1,005 a year in electricity in large U.S. cities, depending on climate and local rates - for example $484 in Phoenix and $832 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 Fujitsu AOUH18LMAS1?
      ENERGY STAR lists 1 certified combination for this outdoor unit. The highest-rated one uses FUJITSU ASUH18LMAS.
      What refrigerant does the Fujitsu AOUH18LMAS1 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 $476/yrYou save $453/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 Fujitsu AOUH18LMAS1
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $476
      Current system, per year
      $928
      You save per year
      $453
      Payback
      15.5 years
      Net after 10 years
      -$2,475

      Cooling $300Heating $175Electricity used: 2,972 kWhSaved vs. a minimum-efficiency heat pump: $236

      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 5, 2026. How we use the data.