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Panasonic vs WILLIS: heat pump ratings compared

Against heat pumps of the same size and type, a typical Panasonic model beats 68% and a typical WILLIS model 63%. Panasonic rates higher overall.

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

Panasonic

68%

of similar heat pumps beaten by its typical model

Well above 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°FPanasonic: Beats 64%WILLIS: Beats 44%
  • Heating power kept at 5°FCapacity at 5°F vs 47°FPanasonic: Beats 72%WILLIS: Beats 71%
  • Winter-long heating efficiencyHSPF2Panasonic: Beats 80%WILLIS: Beats 50%
  • Summer-long cooling efficiencySEER2Panasonic: Beats 66%WILLIS: Beats 69%
  • Hot-day cooling efficiencyEER2Panasonic: Beats 62%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

    Panasonic
    97%
    WILLIS
    97%

  • Xcel CC

    Panasonic
    90%
    WILLIS
    97%

  • CEE Advanced

    Panasonic
    21%
    WILLIS
    10%

  • ENERGY STAR CC

    Panasonic
    79%
    WILLIS
    86%

All-around best, ductless up to 1.5 tons

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

Showing Ductless, Up to 1.5 tons (under 21,000 Btu/h cooling). What size is my system?

Panasonic

  1. 1CU-XZ9AKUACwith ductless indoor unit CS-XZ9AKUAWPanasonic0.5 tons · 8,700 Btu/h · DuctlessCold-climate pick, score 94.9Meets CEE 2025, CEE 2026, CEE Advanced, Xcel CC, DOE CCHP, ENERGY STAR CC
    Heat kept at 5°F
    134% (Capacity at 5°F vs 47°F)
    Top 10%
    Efficiency at 5°F
    2.32 (COP at 5°F)
    Top 10%
    Winter efficiency
    12.0 (HSPF2)
    Top 10%
    Cooling efficiency
    27.5 (SEER2)
    Top 10%
    Hot-day cooling
    16.4 (EER2)
    Top 10%
    95.9score / 100Heating 95 · Cooling 97
  2. 2CU-XZ12AKUACwith ductless indoor unit CS-XZ12AKUAWPanasonic1 ton · 11,500 Btu/h · DuctlessCold-climate pick, score 90.0Meets CEE 2025, CEE 2026, CEE Advanced, Xcel CC, DOE CCHP, ENERGY STAR CC
    Heat kept at 5°F
    119% (Capacity at 5°F vs 47°F)
    Top 10%
    Efficiency at 5°F
    2.11 (COP at 5°F)
    Great
    Winter efficiency
    11.7 (HSPF2)
    Top 10%
    Cooling efficiency
    25.0 (SEER2)
    Great
    Hot-day cooling
    14.4 (EER2)
    Great
    89.2score / 100Heating 90 · Cooling 88
  3. 3CU-YM9CBUCwith ductless indoor unit CS-YM9CKUWPanasonic1 ton · 9,000 Btu/h · DuctlessCold-climate pick, score 85.9Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    82% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    2.33 (COP at 5°F)
    Top 10%
    Winter efficiency
    13.0 (HSPF2)
    Top 10%
    Cooling efficiency
    24.6 (SEER2)
    Great
    Hot-day cooling
    14.7 (EER2)
    Top 10%
    86.7score / 100Heating 86 · Cooling 87

WILLIS

  1. 1AUHW09KR32-Owith ductless indoor unit AUHW09KR32-IWILLIS1 ton · 9,100 Btu/h · DuctlessCold-climate pick, score 87.2Meets CEE 2025, CEE 2026, CEE Advanced, Xcel CC, DOE CCHP, ENERGY STAR CC
    Heat kept at 5°F
    108% (Capacity at 5°F vs 47°F)
    Top 10%
    Efficiency at 5°F
    2.11 (COP at 5°F)
    Great
    Winter efficiency
    11.2 (HSPF2)
    Great
    Cooling efficiency
    30.0 (SEER2)
    Top 10%
    Hot-day cooling
    16.8 (EER2)
    Top 10%
    92.6score / 100Heating 87 · Cooling 98
  2. 2AUHW12KR32-Owith ductless indoor unit AUHW12KR32-IWILLIS1 ton · 12,000 Btu/h · DuctlessCold-climate pick, score 72.1Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    100% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    2.00 (COP at 5°F)
    Good
    Winter efficiency
    10.0 (HSPF2)
    Good
    Cooling efficiency
    29.5 (SEER2)
    Top 10%
    Hot-day cooling
    15.2 (EER2)
    Top 10%
    84.3score / 100Heating 72 · Cooling 97
  3. 3PUHW09KR32-Owith ductless indoor unit PUHW09KR32-IWILLIS1 ton · 9,100 Btu/h · DuctlessCold-climate pick, score 62.2Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    90% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    1.88 (COP at 5°F)
    Below the middle
    Winter efficiency
    10.4 (HSPF2)
    Great
    Cooling efficiency
    26.0 (SEER2)
    Top 10%
    Hot-day cooling
    15.0 (EER2)
    Top 10%
    78.0score / 100Heating 62 · Cooling 94

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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