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      24,000 BTU mini-split heat pump · Hi UNI

      Hisense AOU-24U3T25U

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

      Ranks #274 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $603 a year to run in a mixed climate like Atlanta.

      SEER2
      21.0 Cooling efficiency over a season
      Below average · beats 30%
      HSPF2
      10.5 Heating efficiency over a season
      Average · beats 61%
      EER2
      12.0 Cooling efficiency on a 95°F day
      Below average · beats 25%
      Heat at 5°F
      24,000 BTU/h100% 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 24,000 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.

      Calculate my running cost

      Details

      Specifications24,000 BTU, R-454B
      General
      BrandHisense
      Outdoor unit modelAOU-24U3T25U
      SeriesHi UNI
      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 sinceNovember 2, 2024
      Last certifiedMarch 24, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better21.0 (range 19.0-21.0)
      EER2Efficiency at 95°F outdoors11.0-12.0
      Cooling capacity18,000-24,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.5-10.5
      Capacity at 47°F18,000-24,000 BTU/h
      Capacity at 17°F17,000-19,100 BTU/h
      Capacity at 5°F18,000-24,000 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.80-2.00
      ENERGY STAR cold climateYes
      Heating output as it gets colder100% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with AST-2424DLSI at the standard test temperatures, in BTU/h:

      Certified matchups7 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.
      AST-2424DLSI HISENSE21.012.010.024,000216566123
      ACU-24U3T25U HISENSE · cold climate20.012.010.524,000216498635
      ASU-24U3THB25U HISENSE · cold climate20.011.09.524,000217231616
      ASU-24U3THB25U-B HISENSE · cold climate20.011.09.524,000218026192
      AHU-24U3T25 HISENSE · cold climate19.011.710.024,000217464061
      AHU-18U3T25 HISENSE · cold climate19.011.710.018,000217465405
      ADU-24U3T25U HISENSE · cold climate19.011.79.524,000216498639
      Yearly running cost in 10 large cities$537-$1,442

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

      Questions5
      What is the SEER2 rating of the Hisense AOU-24U3T25U?
      The Hisense AOU-24U3T25U is rated at up to 21.0 SEER2 and 12.0 EER2 for cooling and up to 10.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 7 certified matchups SEER2 ranges from 19.0-21.0.
      Is the Hisense AOU-24U3T25U good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 24,000 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 Hisense AOU-24U3T25U cost to run per year?
      At its rated efficiency it costs about $537-$1,442 a year in electricity in large U.S. cities, depending on climate and local rates - for example $663 in Phoenix and $1,206 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 Hisense AOU-24U3T25U?
      ENERGY STAR lists 7 certified combinations for this outdoor unit. The highest-rated ones use HISENSE AST-2424DLSI, HISENSE ACU-24U3T25U, HISENSE ASU-24U3THB25U.
      What refrigerant does the Hisense AOU-24U3T25U 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 $658/yrYou save $579/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 Hisense AOU-24U3T25U
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $658
      Current system, per year
      $1,238
      You save per year
      $579
      Payback
      15.5 years
      Net after 10 years
      -$3,208

      Cooling $402Heating $256Electricity used: 4,114 kWhSaved vs. a minimum-efficiency heat pump: $291

      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 24, 2026. How we use the data.