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Airdach vs WILLIS: heat pump ratings compared

Against heat pumps of the same size and type, a typical Airdach model beats 40% and a typical WILLIS model 63%. WILLIS rates higher overall.

Covers heat pumps sold new today (R-454B and R-32 refrigerant). See older R-410A models · Updated

Airdach

40%

of similar heat pumps beaten by its typical model

Below average

29 models listed

WILLIS

63%

of similar heat pumps beaten by its typical model

Well above average

29 models listed

Rating by ratingEach bar is the share of same-size, same-type heat pumps that a typical model beats, so the two brands compare fairly even if they make different sizes.
  • Efficiency on a 5°F dayCOP at 5°FAirdach: Beats 48%WILLIS: Beats 44%
  • Heating power kept at 5°FCapacity at 5°F vs 47°FAirdach: Beats 34%WILLIS: Beats 71%
  • Winter-long heating efficiencyHSPF2Airdach: Beats 28%WILLIS: Beats 50%
  • Summer-long cooling efficiencySEER2Airdach: Beats 29%WILLIS: Beats 69%
  • Hot-day cooling efficiencyEER2Airdach: Beats 49%WILLIS: Beats 72%

Average (50%)Dashed outline: the other brand, for comparison

Want ranks, distributions per size class and cold-weather curves? Switch to Advanced

Rebate standards

Share of each brand’s models that meet the level. Programs can have other rules too.

  • CEE 2025

    Airdach
    24%
    WILLIS
    97%

  • Xcel CC

    Airdach
    31%
    WILLIS
    97%

  • CEE Advanced

    Airdach
    0%
    WILLIS
    10%

  • ENERGY STAR CC

    Airdach
    0%
    WILLIS
    86%

All-around best, ducted 3.5–4.5 tons

Balances heating (5°F output and efficiency, HSPF2) and cooling (SEER2, EER2), each rating against units their size.

Showing Ducted, 3.5–4.5 tons (39,000–56,999 Btu/h cooling). What size is my system?

Airdach

  1. 1A3TH60180OV1DGwith ducted air handler A3DH60000OE1DTAirdach4.5 tons · 55,000 Btu/h · DuctedCold-climate pick, score 69.8Meets CEE 2025, CEE 2026, Xcel CC
    Heat kept at 5°F
    73% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    2.30 (COP at 5°F)
    Great
    Winter efficiency
    8.8 (HSPF2)
    Good
    Cooling efficiency
    18.0 (SEER2)
    Great
    Hot-day cooling
    10.0 (EER2)
    Below the middle
    59.5score / 100Heating 70 · Cooling 49
  2. 2A4TH42152MN1DLwith ducted air handler A4DH4800ME1DTAirdach3.5 tons · 41,500 Btu/h · DuctedNot a cold-climate pick: keeps 49% of its heat at 5°FMeets none of the standards tracked here
    Heat kept at 5°F
    50% (Capacity at 5°F vs 47°F)
    Below the middle
    Efficiency at 5°F
    2.30 (COP at 5°F)
    Great
    Winter efficiency
    7.8 (HSPF2)
    Below the middle
    Cooling efficiency
    15.2 (SEER2)
    Below the middle
    Hot-day cooling
    12.0 (EER2)
    Great
    57.2score / 100Heating 50 · Cooling 64
  3. 3A4TH48152MN1DLwith ducted air handler A4DH4800ME1DTAirdach4 tons · 45,000 Btu/h · DuctedNot a cold-climate pick: keeps 48% of its heat at 5°FMeets none of the standards tracked here
    Heat kept at 5°F
    49% (Capacity at 5°F vs 47°F)
    Below the middle
    Efficiency at 5°F
    2.28 (COP at 5°F)
    Great
    Winter efficiency
    7.8 (HSPF2)
    Below the middle
    Cooling efficiency
    14.8 (SEER2)
    Below the middle
    Hot-day cooling
    12.0 (EER2)
    Great
    54.8score / 100Heating 49 · Cooling 61

WILLIS

  1. 1FLEX48KUHR32with ducted air handler FLEXAH48KR32WILLISAlso listed as FLEX60KUHR324 tons · 48,000 Btu/h · DuctedCold-climate pick, score 78.9Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    100% (Capacity at 5°F vs 47°F)
    Top 10%
    Efficiency at 5°F
    2.00 (COP at 5°F)
    Good
    Winter efficiency
    10.0 (HSPF2)
    Great
    Cooling efficiency
    19.0 (SEER2)
    Great
    Hot-day cooling
    12.0 (EER2)
    Great
    83.1score / 100Heating 79 · Cooling 87
  2. 2MZUHW42KR32-OWILLIS3.5 tons · 42,000 Btu/h · DuctedCold-climate pick, score 55.7Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    86% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    1.90 (COP at 5°F)
    Below the middle
    Winter efficiency
    8.1 (HSPF2)
    Good
    Cooling efficiency
    18.0 (SEER2)
    Great
    Hot-day cooling
    12.0 (EER2)
    Great
    69.1score / 100Heating 56 · Cooling 83

These are certified test ratings, not a recommendation for your home. The right size comes from a load calculation by a contractor.

Next steps

The advanced view adds ranks, both brands’ models inside every size class, standout models per rating and cold-weather curves.

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