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      3-ton central heat pump · D5F Series

      Day & Night D5CUHAH36AAK

      Average cooling efficiency and excellent heating efficiency for a 3-ton central heat pump, and certified for cold climates.

      Ranks #89 of 302 3 ton central heat pumps for cooling efficiency, and costs about $1,003 a year to run in a mixed climate like Atlanta.

      SEER2
      18.0 Cooling efficiency over a season
      Average · beats 66%
      HSPF2
      10.3 Heating efficiency over a season
      Excellent · beats 92%
      EER2
      12.0 Cooling efficiency on a 95°F day
      Average · beats 64%
      Heat at 5°F
      39,000 BTU/h101% of its 47°F output
      Below average · beats 20%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 39,000 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 92% of central heat pumps.
      • You want steady temperatures and quiet running - the compressor varies its speed.
      • You want a choice of indoor units - 89 certified pairings.

      Think twice if…

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

      Calculate my running cost

      Details

      Specifications3 ton, R-454B
      General
      BrandDay & Night
      Also sold asHeil, Smart Comfort, Midea, Arcoaire, Keeprite, Tempstar, Airquest, Comfortmaker, Viessmann, LPS Legacy, Grandaire, Kenmore, Carrier, Bryant, Payne, WeatherMaker
      Outdoor unit modelD5CUHAH36AAK
      SeriesD5F Series
      TypeCentral heat pump
      Nominal size3 ton
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceNovember 15, 2018
      Last certifiedSeptember 22, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better18.0 (range 15.8-18.0)
      EER2Efficiency at 95°F outdoors10.7-12.0
      Cooling capacity36,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.4-10.3
      Capacity at 47°F37,000-38,000 BTU/h
      Capacity at 17°F29,200-33,000 BTU/h
      Capacity at 5°F34,600-39,000 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.80-1.90
      ENERGY STAR cold climateYes
      Heating output as it gets colder101% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with D5FUHAH36XAK at the standard test temperatures, in BTU/h:

      Certified matchups89 indoor units

      The same outdoor unit scores differently with each indoor unit. The 60 highest-rated of 89 are shown. Ask your installer for the AHRI reference number of the exact system you are quoted.

      Indoor unitSEER2EER2HSPF2Heat @5°FAHRI ref.
      D5FUHAH36XAK · cold climate18.012.010.037,400215323725
      D5FUHAH36XAK · cold climate18.012.010.037,400215323726
      D5FUHAH36XAK · cold climate18.012.010.037,400215323727
      D5FUHAH36XAK · cold climate18.012.010.037,400215323728
      D5FUHAH36XAK · cold climate18.012.010.037,400215323729
      D5FUHAH36XAK · cold climate18.012.010.037,400215323730
      D5FUHAH36XAK · cold climate18.012.010.037,400215323731
      D5FUHAH36XAK · cold climate18.012.010.037,400215323732
      D5FUHAH36XAK · cold climate18.012.010.037,400215323733
      D5FUHAH36XAK · cold climate18.012.010.037,400215323734
      D5FUHAH36XAK · cold climate18.012.010.037,400215323736
      D5FUHAH36XAK · cold climate18.012.010.037,400215323735
      D5FUHAH36XAK · cold climate18.012.010.037,400217178768
      D5FUAAH36XAK · cold climate17.411.710.339,000215318947
      D5FUAAH36XAK · cold climate17.411.710.339,000215318975
      D5FUAAH36XAK · cold climate17.411.710.339,000215319115
      D5FUAAH36XAK · cold climate17.411.710.339,000215319059
      D5FUAAH36XAK · cold climate17.411.710.339,000215318891
      D5FUAAH36XAK · cold climate17.411.710.339,000215319003
      D5FUAAH36XAK · cold climate17.411.710.339,000215319087
      D5FUAAH36XAK · cold climate17.411.710.339,000215319143
      D5FUAAH36XAK · cold climate17.411.710.339,000215319171
      D5FUAAH36XAK · cold climate17.411.710.339,000215319199
      D5FUAAH36XAK · cold climate17.411.710.339,000215318919
      D5FUAAH36XAK · cold climate17.411.710.339,000215319031
      D5FUAAH36XAK · cold climate17.411.710.339,000217178767
      D5MUWAQ36XA3 · cold climate16.811.29.634,600217730620
      D5MUWAQ36XA3 · cold climate16.811.29.634,600217730636
      D5MUWAQ36XA3 · cold climate16.811.29.634,600217730652
      D5MUWAQ36XA3 · cold climate16.811.29.634,600217730668
      D5MUWAQ36XA3 · cold climate16.811.29.634,600217730684
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213799
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213793
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213787
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213781
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213775
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213769
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213763
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213757
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213751
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213745
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218213739
      D5MUWAQ36XA3 · cold climate16.811.29.634,600218668524
      D5FULAH36XBX · cold climate15.810.79.436,000217456528
      D5FULAH36XCX · cold climate15.810.79.436,000217456529
      D5FULAH36XBX · cold climate15.810.79.436,000217456500
      D5FULAH36XCX · cold climate15.810.79.436,000217456501
      D5FULAH36XBX · cold climate15.810.79.436,000217456612
      D5FULAH36XBX · cold climate15.810.79.436,000217456668
      D5FULAH36XCX · cold climate15.810.79.436,000217456669
      D5FULAH36XBX · cold climate15.810.79.436,000217456752
      D5FULAH36XCX · cold climate15.810.79.436,000217456753
      D5FULAH36XBX · cold climate15.810.79.436,000217456584
      D5FULAH36XCX · cold climate15.810.79.436,000217456585
      D5FULAH36XBX · cold climate15.810.79.436,000217456444
      D5FULAH36XCX · cold climate15.810.79.436,000217456445
      D5FULAH36XCX · cold climate15.810.79.436,000217456613
      D5FULAH36XBX · cold climate15.810.79.436,000217456696
      D5FULAH36XCX · cold climate15.810.79.436,000217456697
      D5FULAH36XBX · cold climate15.810.79.436,000217456778
      Yearly running cost in 10 large cities$938-$2,365

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

      Questions5
      What is the SEER2 rating of the Day & Night D5CUHAH36AAK?
      The Day & Night D5CUHAH36AAK is rated at up to 18.0 SEER2 and 12.0 EER2 for cooling and up to 10.3 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 89 certified matchups SEER2 ranges from 15.8-18.0.
      Is the Day & Night D5CUHAH36AAK good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 39,000 BTU/h at 5°F with a COP of 1.90, so it is still 1.9 times as efficient as electric resistance heat at that temperature.
      How much does the Day & Night D5CUHAH36AAK cost to run per year?
      At its rated efficiency it costs about $938-$2,365 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,136 in Phoenix and $1,961 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 Day & Night D5CUHAH36AAK?
      ENERGY STAR lists 89 certified combinations for this outdoor unit. The highest-rated ones use D5FUHAH36XAK, D5FUAAH36XAK, D5MUWAQ36XA3.
      What refrigerant does the Day & Night D5CUHAH36AAK 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 $1,117/yrYou save $772/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 Day & Night D5CUHAH36AAK
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $1,117
      Current system, per year
      $1,889
      You save per year
      $772
      Payback
      17.5 years
      Net after 10 years
      -$5,782

      Cooling $704Heating $413Electricity used: 6,983 kWhSaved vs. a minimum-efficiency heat pump: $336

      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 3 ton models

      See all 302 3 ton central heat pumps, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of September 22, 2026. How we use the data.