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

      KEEN Home KEENUMHP18AA

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

      Ranks #368 of 465 18,000 BTU mini-splits for cooling efficiency, and costs about $433 a year to run in a mixed climate like Atlanta.

      SEER2
      20.6 Cooling efficiency over a season
      Below average · beats 25%
      HSPF2
      12.2 Heating efficiency over a season
      Excellent · beats 91%
      EER2
      12.5 Cooling efficiency on a 95°F day
      Average · beats 44%
      Heat at 5°F
      17,500 BTU/h88% of its 47°F output
      Below average · beats 22%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 17,500 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 91% 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.

      Calculate my running cost

      Details

      Specifications18,000 BTU, R-454B
      General
      BrandKEEN Home
      Outdoor unit modelKEENUMHP18AA
      SeriesKEEN Series
      TypeMini-split heat pump
      Nominal size18,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceJuly 4, 2025
      Last certifiedJuly 17, 2025
      Cooling
      SEER2Seasonal efficiency, higher is better20.6 (range 20.4-20.6)
      EER2Efficiency at 95°F outdoors12.5
      Cooling capacity16,700-17,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better10.3-12.2
      Capacity at 47°F19,000-20,000 BTU/h
      Capacity at 17°F14,400-14,500 BTU/h
      Capacity at 5°F17,000-17,500 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.86-1.89
      ENERGY STAR cold climateYes
      Heating output as it gets colder88% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with KEENOWAH18AA at the standard test temperatures, in BTU/h:

      Certified matchups2 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.
      KEENOWAH18AA · cold climate20.612.512.217,500217596901
      KEENFCAH18AA · cold climate20.412.510.317,000217596902
      Yearly running cost in 10 large cities$388-$1,036

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

      Questions5
      What is the SEER2 rating of the KEEN Home KEENUMHP18AA?
      The KEEN Home KEENUMHP18AA is rated at up to 20.6 SEER2 and 12.5 EER2 for cooling and up to 12.2 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 2 certified matchups SEER2 ranges from 20.4-20.6.
      Is the KEEN Home KEENUMHP18AA good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 17,500 BTU/h at 5°F with a COP of 1.89, so it is still 1.9 times as efficient as electric resistance heat at that temperature.
      How much does the KEEN Home KEENUMHP18AA cost to run per year?
      At its rated efficiency it costs about $388-$1,036 a year in electricity in large U.S. cities, depending on climate and local rates - for example $478 in Phoenix and $865 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 KEEN Home KEENUMHP18AA?
      ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated ones use KEENOWAH18AA, KEENFCAH18AA.
      What refrigerant does the KEEN Home KEENUMHP18AA 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 $474/yrYou save $452/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 KEEN Home KEENUMHP18AA
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $474
      Current system, per year
      $926
      You save per year
      $452
      Payback
      14.4 years
      Net after 10 years
      -$1,984

      Cooling $290Heating $184Electricity used: 2,963 kWhSaved vs. a minimum-efficiency heat pump: $243

      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 July 17, 2025. How we use the data.