HVAC Rated
    Menu

      3-ton central heat pump · 2-STAGE 18 SEER HP

      Grandaire W5H8T36*K*AAA

      Average cooling efficiency and below average heating efficiency for a 3-ton central heat pump, but not rated for cold climates.

      Ranks #165 of 302 3 ton central heat pumps for cooling efficiency, and costs about $1,151 a year to run in a mixed climate like Atlanta.

      SEER2
      17.0 Cooling efficiency over a season
      Average · beats 49%
      HSPF2
      8.5 Heating efficiency over a season
      Below average · beats 38%
      EER2
      13.0 Cooling efficiency on a 95°F day
      Very good · beats 89%
      Heat at 5°F
      19,600 BTU/h49% of its 47°F output
      Excellent · beats 98%

      A good fit if…

      • You want a choice of indoor units - 138 certified pairings.

      Think twice if…

      • You often see nights below 0°F - it is not cold-climate certified.
      • You mainly need heat - its HSPF2 is below average for central heat pumps.

      Calculate my running cost

      Details

      Specifications3 ton, R-454B
      General
      BrandGrandaire
      Also sold asECOTEMP
      Outdoor unit modelW5H8T36*K*AAA
      Series2-STAGE 18 SEER HP
      TypeCentral heat pump
      Nominal size3 ton
      CompressorVariable-speed units run longer at low powerTwo-stage
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceNovember 4, 2024
      Last certifiedSeptember 16, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better17.0 (range 15.2-17.0)
      EER2Efficiency at 95°F outdoors11.7-13.0
      Cooling capacity33,800-38,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better7.8-8.5
      Capacity at 47°F37,200-39,000 BTU/h
      Capacity at 17°F23,000-24,200 BTU/h
      Capacity at 5°F17,500-19,600 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.78-2.48
      ENERGY STAR cold climateNo
      Heating output as it gets colder49% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with WCGL605*D at the standard test temperatures, in BTU/h:

      Certified matchups138 indoor units

      The same outdoor unit scores differently with each indoor unit and furnace. The 60 highest-rated of 138 are shown. Ask your installer for the AHRI reference number of the exact system you are quoted.

      Indoor unitFurnaceSEER2EER2HSPF2Heat @5°FAHRI ref.
      WCGL605*D-17.013.08.518,600215628959
      WCGL605*D-17.013.08.518,600215628960
      WCGL485*C-16.512.58.118,700215628906
      WCGL485*C-16.512.58.118,700215628905
      QFVA5D4821X-16.513.08.118,400218695421
      QFVA5D4821X-16.513.08.118,400218695420
      W5A*43M21XAWFEU080C060B*16.012.08.519,100215637810
      W5A*43M21XAWFEU080C060B*16.012.08.519,100215637812
      W5A*43M21XAWFEU060B048B*16.012.08.119,300215637782
      W5A*43M21XAWFEU060B048B*16.012.08.119,300215637783
      W5A*48M21XAWFEU080C060B*16.012.08.119,000215638906
      W5A*48M21XAWFEU080C060B*16.012.08.119,000215638905
      QFVA5D3617X-16.012.58.118,300218695404
      QFVA5D3617X-16.012.58.118,300218695403
      W5VM48M21XAWFEU080C060B*16.012.58.017,500215619549
      W5VM48M21XAWFEU080C060B*16.012.58.017,500215619550
      W5VM49M21XAWFEU080C060B*16.012.58.017,700215619913
      W5VM49M21XAWFEU080C060B*16.012.58.017,700215619914
      W5VM49M21XAWFST100C060A*16.012.58.017,900215620093
      W5VM49M21XAWFST100C060A*16.012.58.017,900215620092
      W5VC38M17XAWFEU040B036B*16.012.58.017,600215621339
      W5VC38M17XAWFEU040B036B*16.012.58.017,600215621338
      W5VC38M17XAWFEU060B048B*16.012.58.017,600215621358
      W5VC38M17XAWFEU060B048B*16.012.58.017,600215621357
      W5VC38M17XAWFET090B048A*16.012.58.017,600215621450
      W5VC38M17XAWFET090B048A*16.012.58.017,600215621449
      W5VM49M21XAWFJT100C060A*16.012.58.017,900215716310
      W5VM49M21XAWFJT100C060A*16.012.58.017,900215716311
      W5A*42M21XAWFEU080C060B*15.512.08.118,800215636667
      W5A*42M21XAWFEU080C060B*15.512.08.118,800215636665
      W5A*43M21XAWFEU040B036B*15.512.08.119,300215637755
      W5A*43M21XAWFEU040B036B*15.512.08.119,300215637757
      W5A*43M21XAWFEU100C060B*15.512.08.119,400215637840
      W5A*43M21XAWFEU100C060B*15.512.08.119,400215637839
      W5A*48M21XAWFEU040B036B*15.511.78.119,200215638848
      W5A*48M21XAWFEU040B036B*15.511.78.119,200215638846
      W5A*43M21XAWFET090B048A*15.512.08.119,300215638005
      W5A*43M21XAWFET090B048A*15.512.08.119,300215638006
      W5A*43M21XAWFET110C066A*15.512.08.119,200215638056
      W5A*43M21XAWFET110C066A*15.512.08.119,200215638058
      W5A*43M21XAWFSU080C060B*15.512.08.119,300215638362
      W5A*43M21XAWFSU080C060B*15.512.08.119,300215638361
      W5A*43M21XAWFSU100C060B*15.511.78.119,400215638389
      W5A*43M21XAWFSU100C060B*15.511.78.119,400215638387
      W5A*43M21XAWFST100C060A*15.512.08.119,200215638615
      W5A*43M21XAWFST100C060A*15.512.08.119,200215638617
      W5A*48M21XAWFEU060B048B*15.512.08.119,000215638875
      W5A*48M21XAWFEU060B048B*15.512.08.119,000215638876
      W5A*48M21XAWFEU100C060B*15.511.78.119,300215638933
      W5A*48M21XAWFEU100C060B*15.511.78.119,300215638934
      W5A*48M21XAWFET110C066A*15.512.08.119,100215639145
      W5A*48M21XAWFET110C066A*15.512.08.119,100215639146
      W5A*48M21XAWFST100C060A*15.511.78.119,100215639742
      W5A*48M21XAWFST100C060A*15.511.78.119,100215639741
      W5A*48M21XAWFSU100C060B*15.511.78.119,100215639521
      W5A*48M21XAWFSU100C060B*15.511.78.119,100215639523
      W5SH42M12XAWFEU080C060B*15.512.08.119,000215641034
      W5SH42M12XAWFEU080C060B*15.512.08.119,000215641035
      W5A*37M17XAWFEU040B036B*15.512.08.118,800217191528
      W5A*37M17XAWFEU040B036B*15.512.08.118,800217191529
      Yearly running cost in 10 large cities$986-$2,787

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

      Questions5
      What is the SEER2 rating of the Grandaire W5H8T36*K*AAA?
      The Grandaire W5H8T36*K*AAA is rated at up to 17.0 SEER2 and 13.0 EER2 for cooling and up to 8.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 138 certified matchups SEER2 ranges from 15.2-17.0.
      Is the Grandaire W5H8T36*K*AAA good for cold climates?
      It is not cold-climate certified: none of its matchups meet the ENERGY STAR cold-climate criteria (a COP of at least 1.75 at 5°F among other limits). In places with frequent sub-zero nights, pick a cold-climate 3-ton model.
      How much does the Grandaire W5H8T36*K*AAA cost to run per year?
      At its rated efficiency it costs about $986-$2,787 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,237 in Phoenix and $2,344 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 Grandaire W5H8T36*K*AAA?
      ENERGY STAR lists 138 certified combinations for this outdoor unit. The highest-rated ones use WCGL605*D, WCGL485*C, QFVA5D4821X.
      What refrigerant does the Grandaire W5H8T36*K*AAA 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 $1,238/yrYou save $637/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 Grandaire W5H8T36*K*AAA
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $1,238
      Current system, per year
      $1,875
      You save per year
      $637
      Payback
      21.2 years
      Net after 10 years
      -$7,129

      Cooling $737Heating $501Electricity used: 7,736 kWhSaved vs. a minimum-efficiency heat pump: $206

      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 16, 2026. How we use the data.