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      2-ton central heat pump · SAK Series

      Star Air Kontrol SAK-24ADN2-M18M

      Average cooling and heating efficiency for a 2-ton central heat pump, and certified for cold climates.

      Ranks #226 of 331 2 ton central heat pumps for cooling efficiency, and costs about $745 a year to run in a mixed climate like Atlanta.

      SEER2
      17.0 Cooling efficiency over a season
      Average · beats 49%
      HSPF2
      9.2 Heating efficiency over a season
      Average · beats 61%
      EER2
      10.5 Cooling efficiency on a 95°F day
      Below average · beats 17%
      Heat at 5°F
      19,400 BTU/h75% of its 47°F output
      Average · beats 58%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 19,400 BTU/h at 5°F.
      • You want steady temperatures and quiet running - the compressor varies its speed.

      Think twice if…

      • You want the newest refrigerant - it uses R-410A, which is being phased down.

      Calculate my running cost

      Details

      Specifications2 ton, R-410A
      General
      BrandStar Air Kontrol
      Outdoor unit modelSAK-24ADN2-M18M
      SeriesSAK Series
      TypeCentral heat pump
      Nominal size2 ton
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-410A
      Connected (smart) capableNo
      On the market sinceApril 28, 2024
      Last certifiedJune 3, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better17.0 (range 17.0)
      EER2Efficiency at 95°F outdoors10.5
      Cooling capacity24,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.2
      Capacity at 47°F26,000 BTU/h
      Capacity at 17°F21,000 BTU/h
      Capacity at 5°F19,400 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.10
      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 SAK-24WN1-M18 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.
      SAK-24WN1-M18 · cold climate17.010.59.219,400211726529
      SAK-24GN1-M18 · cold climate17.010.59.219,400216025752
      Yearly running cost in 10 large cities$664-$1,783

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

      Questions5
      What is the SEER2 rating of the Star Air Kontrol SAK-24ADN2-M18M?
      The Star Air Kontrol SAK-24ADN2-M18M is rated at up to 17.0 SEER2 and 10.5 EER2 for cooling and up to 9.2 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the Star Air Kontrol SAK-24ADN2-M18M good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 19,400 BTU/h at 5°F with a COP of 2.10, so it is still 2.1 times as efficient as electric resistance heat at that temperature.
      How much does the Star Air Kontrol SAK-24ADN2-M18M cost to run per year?
      At its rated efficiency it costs about $664-$1,783 a year in electricity in large U.S. cities, depending on climate and local rates - for example $819 in Phoenix and $1,491 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 Star Air Kontrol SAK-24ADN2-M18M?
      ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated ones use SAK-24WN1-M18, SAK-24GN1-M18.
      What refrigerant does the Star Air Kontrol SAK-24ADN2-M18M 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 $813/yrYou save $457/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 Star Air Kontrol SAK-24ADN2-M18M
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $813
      Current system, per year
      $1,270
      You save per year
      $457
      Payback
      19.7 years
      Net after 10 years
      -$4,432

      Cooling $497Heating $317Electricity used: 5,084 kWhSaved vs. a minimum-efficiency heat pump: $166

      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 2 ton models

      See all 331 2 ton central heat pumps, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of June 3, 2026. How we use the data.