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COMFORTSTAR vs ZERO: heat pump ratings compared

Against heat pumps of the same size and type, a typical COMFORTSTAR model beats 50% and a typical ZERO model 53%. ZERO rates slightly higher overall.

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

COMFORTSTAR

50%

of similar heat pumps beaten by its typical model

About average

133 models listed

ZERO

53%

of similar heat pumps beaten by its typical model

About average

119 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°FCOMFORTSTAR: Beats 51%ZERO: Beats 45%
  • Heating power kept at 5°FCapacity at 5°F vs 47°FCOMFORTSTAR: Beats 48%ZERO: Beats 52%
  • Winter-long heating efficiencyHSPF2COMFORTSTAR: Beats 54%ZERO: Beats 57%
  • Summer-long cooling efficiencySEER2COMFORTSTAR: Beats 49%ZERO: Beats 58%
  • Hot-day cooling efficiencyEER2COMFORTSTAR: Beats 44%ZERO: Beats 48%

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

    COMFORTSTAR
    53%
    ZERO
    71%

  • Xcel CC

    COMFORTSTAR
    47%
    ZERO
    65%

  • CEE Advanced

    COMFORTSTAR
    2%
    ZERO
    0%

  • ENERGY STAR CC

    COMFORTSTAR
    30%
    ZERO
    53%

All-around best, ductless 2 tons

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

Showing Ductless, 2 tons (21,000–26,999 Btu/h cooling). What size is my system?

COMFORTSTAR

  1. 1CPP3-24CD(O)with ductless indoor unit CPP3-24CD(I)COMFORTSTAR2 tons · 24,000 Btu/h · DuctlessCold-climate pick, score 77.9Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    71% (Capacity at 5°F vs 47°F)
    Below the middle
    Efficiency at 5°F
    2.15 (COP at 5°F)
    Great
    Winter efficiency
    10.0 (HSPF2)
    Good
    Cooling efficiency
    23.5 (SEER2)
    Top 10%
    Hot-day cooling
    13.0 (EER2)
    Great
    74.3score / 100Heating 64 · Cooling 85
  2. 2CHF3-24CD(O)with ductless indoor unit CPP3-24CD(I)COMFORTSTAR2 tons · 23,000 Btu/h · DuctlessCold-climate pick, score 89.4Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    92% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    2.00 (COP at 5°F)
    Good
    Winter efficiency
    13.3 (HSPF2)
    Top 10%
    Cooling efficiency
    22.3 (SEER2)
    Good
    Hot-day cooling
    12.5 (EER2)
    Good
    72.9score / 100Heating 77 · Cooling 69
  3. 3CMZ3-30-4ZCOMFORTSTAR2 tons · 26,000 Btu/h · DuctlessCold-climate pick, score 41.1Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    70% (Capacity at 5°F vs 47°F)
    Below the middle
    Efficiency at 5°F
    2.00 (COP at 5°F)
    Good
    Winter efficiency
    9.5 (HSPF2)
    Below the middle
    Cooling efficiency
    23.0 (SEER2)
    Great
    Hot-day cooling
    12.2 (EER2)
    Good
    56.7score / 100Heating 41 · Cooling 72

ZERO

  1. 1ZMSB-24HV-USHHR2-Owith ductless indoor unit ZMSB-24HV-USHHR2-IZERO2 tons · 24,000 Btu/h · DuctlessCold-climate pick, score 73.7Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    71% (Capacity at 5°F vs 47°F)
    Below the middle
    Efficiency at 5°F
    2.15 (COP at 5°F)
    Great
    Winter efficiency
    10.0 (HSPF2)
    Good
    Cooling efficiency
    23.5 (SEER2)
    Top 10%
    Hot-day cooling
    13.0 (EER2)
    Great
    74.3score / 100Heating 64 · Cooling 85
  2. 2ZMSB-24HV-USHHCR2-Owith ductless indoor unit ZMSB-24HV-USHHCR2-IZERO2 tons · 23,000 Btu/h · DuctlessCold-climate pick, score 77.2Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    92% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    2.00 (COP at 5°F)
    Good
    Winter efficiency
    13.3 (HSPF2)
    Top 10%
    Cooling efficiency
    22.3 (SEER2)
    Good
    Hot-day cooling
    12.5 (EER2)
    Good
    72.9score / 100Heating 77 · Cooling 69
  3. 3ZMSB-24HVT-USR1-S23-Owith ductless indoor unit ZMSB-24HVT-USR1-S23-IZERO2 tons · 23,000 Btu/h · DuctlessCold-climate pick, score 61.6Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    73% (Capacity at 5°F vs 47°F)
    Below the middle
    Efficiency at 5°F
    2.10 (COP at 5°F)
    Good
    Winter efficiency
    10.0 (HSPF2)
    Good
    Cooling efficiency
    23.0 (SEER2)
    Great
    Hot-day cooling
    12.0 (EER2)
    Good
    64.8score / 100Heating 62 · Cooling 68

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