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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, ductless 5 tons and up

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

Airdach

No ductless, 5 tons and up model from Airdach.

WILLIS

No ductless, 5 tons and up model from WILLIS.

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.

Open the advanced view