HVAC Rated
    Menu

      24,000 BTU mini-split heat pump · AO Series

      AI AIR CONDITIONING AO24-24N2-M1

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

      Ranks #70 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $573 a year to run in a mixed climate like Atlanta.

      SEER2
      23.5 Cooling efficiency over a season
      Very good · beats 70%
      HSPF2
      11.1 Heating efficiency over a season
      Very good · beats 78%
      EER2
      13.0 Cooling efficiency on a 95°F day
      Average · beats 62%
      Heat at 5°F
      19,000 BTU/h71% of its 47°F output
      Very good · beats 86%

      A good fit if…

      • You want low cooling bills - its SEER2 beats 70% of mini-splits.
      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 19,000 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…

      • Nothing stands out - its ratings have no weak spot for its class.

      Calculate my running cost

      Details

      Specifications24,000 BTU, R-454B
      General
      BrandAI AIR CONDITIONING
      Also sold asComfortStar, Mitsutomo, DuraSTAR, Multi MFG, Wells
      Outdoor unit modelAO24-24N2-M1
      SeriesAO Series
      TypeMini-split heat pump
      Nominal size24,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceOctober 10, 2024
      Last certifiedMay 6, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better23.5 (range 19.0-23.5)
      EER2Efficiency at 95°F outdoors11.7-13.0
      Cooling capacity24,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.0-11.1
      Capacity at 47°F24,400-25,000 BTU/h
      Capacity at 17°F17,600-22,400 BTU/h
      Capacity at 5°F17,800-19,000 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.15-2.30
      ENERGY STAR cold climateYes
      Heating output as it gets colder71% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with AW25-24N2-M1 at the standard test temperatures, in BTU/h:

      Certified matchups5 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.
      AW25-24N2-M1 · cold climate23.513.010.017,800215866733
      AC-24N2-M1 · cold climate22.012.010.518,500215866747
      AF-24N2-M1 · cold climate21.112.211.118,600215866767
      AAH-24N2-BM1 · cold climate19.711.79.018,000217162305
      AH-24N2-M1 · cold climate19.012.511.019,000215866759
      Same unit, other model numbers5

      These model numbers have exactly the same certified ratings and matchups as the AI AIR CONDITIONING AO24-24N2-M1: 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$482-$1,396

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

      Questions6
      What is the SEER2 rating of the AI AIR CONDITIONING AO24-24N2-M1?
      The AI AIR CONDITIONING AO24-24N2-M1 is rated at up to 23.5 SEER2 and 13.0 EER2 for cooling and up to 11.1 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 5 certified matchups SEER2 ranges from 19.0-23.5.
      Is the AI AIR CONDITIONING AO24-24N2-M1 good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 19,000 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 AI AIR CONDITIONING AO24-24N2-M1 cost to run per year?
      At its rated efficiency it costs about $482-$1,396 a year in electricity in large U.S. cities, depending on climate and local rates - for example $609 in Phoenix and $1,178 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
      Is the AI AIR CONDITIONING AO24-24N2-M1 the same as the ComfortStar CPP3-24CD(O)?
      Yes, as far as the certified ratings go. ENERGY STAR lists 6 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 AI AIR CONDITIONING AO24-24N2-M1?
      ENERGY STAR lists 5 certified combinations for this outdoor unit. The highest-rated ones use AW25-24N2-M1, AC-24N2-M1, AF-24N2-M1.
      What refrigerant does the AI AIR CONDITIONING AO24-24N2-M1 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 $612/yrYou save $642/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 AI AIR CONDITIONING AO24-24N2-M1
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $612
      Current system, per year
      $1,254
      You save per year
      $642
      Payback
      14.0 years
      Net after 10 years
      -$2,579

      Cooling $359Heating $252Electricity used: 3,823 kWhSaved vs. a minimum-efficiency heat pump: $352

      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.

      Similar 24,000 BTU models

      See all 430 24,000 BTU mini-splits, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of May 6, 2026. How we use the data.