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      24,000 BTU mini-split heat pump · Harmony

      Ouellet OCHX-H24A-O

      Below average cooling and heating efficiency for a 24,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #388 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $684 a year to run in a mixed climate like Atlanta.

      SEER2
      19.0 Cooling efficiency over a season
      Below average · beats 9%
      HSPF2
      8.5 Heating efficiency over a season
      Below average · beats 2%
      EER2
      11.9 Cooling efficiency on a 95°F day
      Below average · beats 19%
      Heat at 5°F
      16,800 BTU/h75% of its 47°F output
      Below average · beats 16%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 16,800 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.

      Calculate my running cost

      Details

      Specifications24,000 BTU, R-32
      General
      BrandOuellet
      Outdoor unit modelOCHX-H24A-O
      SeriesHarmony
      TypeMini-split heat pump
      Nominal size24,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-32
      Connected (smart) capableNo
      On the market sinceOctober 20, 2025
      Last certifiedDecember 2, 2025
      Cooling
      SEER2Seasonal efficiency, higher is better19.0 (range 19.0)
      EER2Efficiency at 95°F outdoors11.9
      Cooling capacity24,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better8.5
      Capacity at 47°F22,400 BTU/h
      Capacity at 17°F19,200 BTU/h
      Capacity at 5°F16,800 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.81
      ENERGY STAR cold climateYes
      Heating output as it gets colder75% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with OCHX-H24A-I 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.
      OCHX-H24A-I OUELLET · cold climate19.011.98.516,800216472863
      Yearly running cost in 10 large cities$595-$1,650

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

      Questions5
      What is the SEER2 rating of the Ouellet OCHX-H24A-O?
      The Ouellet OCHX-H24A-O is rated at up to 19.0 SEER2 and 11.9 EER2 for cooling and up to 8.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the Ouellet OCHX-H24A-O good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 16,800 BTU/h at 5°F with a COP of 1.81, so it is still 1.8 times as efficient as electric resistance heat at that temperature.
      How much does the Ouellet OCHX-H24A-O cost to run per year?
      At its rated efficiency it costs about $595-$1,650 a year in electricity in large U.S. cities, depending on climate and local rates - for example $741 in Phoenix and $1,385 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 Ouellet OCHX-H24A-O?
      ENERGY STAR lists 1 certified combination for this outdoor unit. The highest-rated one uses OUELLET OCHX-H24A-I.
      What refrigerant does the Ouellet OCHX-H24A-O use?
      It uses 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 $740/yrYou save $472/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 Ouellet OCHX-H24A-O
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $740
      Current system, per year
      $1,211
      You save per year
      $472
      Payback
      19.1 years
      Net after 10 years
      -$4,285

      Cooling $445Heating $295Electricity used: 4,624 kWhSaved vs. a minimum-efficiency heat pump: $185

      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 December 2, 2025. How we use the data.