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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 48% and a typical ZERO model 49%. ZERO rates slightly higher overall.

Covers older R-410A heat pumps, no longer installed new. See models sold today · Updated

COMFORTSTAR

48%

of similar heat pumps beaten by its typical model

About average

117 models listed

ZERO

49%

of similar heat pumps beaten by its typical model

About average

69 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 46%ZERO: Beats 48%
  • Heating power kept at 5°FCapacity at 5°F vs 47°FCOMFORTSTAR: Beats 44%ZERO: Beats 43%
  • Winter-long heating efficiencyHSPF2COMFORTSTAR: Beats 49%ZERO: Beats 46%
  • Summer-long cooling efficiencySEER2COMFORTSTAR: Beats 44%ZERO: Beats 53%
  • Hot-day cooling efficiencyEER2COMFORTSTAR: Beats 44%ZERO: Beats 46%

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
    37%
    ZERO
    59%

  • Xcel CC

    COMFORTSTAR
    24%
    ZERO
    48%

  • CEE Advanced

    COMFORTSTAR
    1%
    ZERO
    0%

  • ENERGY STAR CC

    COMFORTSTAR
    22%
    ZERO
    25%

All-around best, ducted 2.5–3 tons

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

Showing Ducted, 2.5–3 tons (27,000–38,999 Btu/h cooling), the most-listed ducted size. Pick yours above. What size is my system?

COMFORTSTAR

  1. 1CMZ-27-3ZCOMFORTSTAR2.5 tons · 28,000 Btu/h · DuctedNot a cold-climate pick: keeps 66% of its heat at 5°FMeets CEE 2025, CEE 2026
    Heat kept at 5°F
    67% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    2.00 (COP at 5°F)
    Good
    Winter efficiency
    9.2 (HSPF2)
    Good
    Cooling efficiency
    21.0 (SEER2)
    Top 10%
    Hot-day cooling
    11.7 (EER2)
    Good
    75.4score / 100Heating 65 · Cooling 86
  2. 2CVH-27-3SHCOMFORTSTAR2.5 tons · 28,000 Btu/h · DuctedCold-climate pick, score 66.7Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    89% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    1.80 (COP at 5°F)
    Below the middle
    Winter efficiency
    9.5 (HSPF2)
    Great
    Cooling efficiency
    20.0 (SEER2)
    Top 10%
    Hot-day cooling
    11.7 (EER2)
    Good
    74.6score / 100Heating 67 · Cooling 83
  3. 3CVH-36-4SHCOMFORTSTAR3 tons · 36,000 Btu/h · DuctedCold-climate pick, score 63.7Meets none of the standards tracked here
    Heat kept at 5°F
    89% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    1.70 (COP at 5°F)
    Below the middle
    Winter efficiency
    10.0 (HSPF2)
    Top 10%
    Cooling efficiency
    19.0 (SEER2)
    Great
    Hot-day cooling
    11.7 (EER2)
    Good
    71.2score / 100Heating 64 · Cooling 79

ZERO

  1. 1Z3SOV-27HDM-USZERO2.5 tons · 28,000 Btu/h · DuctedCold-climate pick, score 57.4Meets CEE 2025, CEE 2026, Xcel CC
    Heat kept at 5°F
    71% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    1.83 (COP at 5°F)
    Below the middle
    Winter efficiency
    9.2 (HSPF2)
    Good
    Cooling efficiency
    21.0 (SEER2)
    Top 10%
    Hot-day cooling
    11.7 (EER2)
    Good
    71.5score / 100Heating 57 · Cooling 86
  2. 2Z4SOV-36HDM-USZERO3 tons · 36,000 Btu/h · DuctedNot a cold-climate pick: keeps 64% of its heat at 5°FMeets none of the standards tracked here
    Heat kept at 5°F
    65% (Capacity at 5°F vs 47°F)
    Below the middle
    Efficiency at 5°F
    1.68 (COP at 5°F)
    Below the middle
    Winter efficiency
    9.2 (HSPF2)
    Good
    Cooling efficiency
    20.0 (SEER2)
    Top 10%
    Hot-day cooling
    11.0 (EER2)
    Below the middle
    56.6score / 100Heating 44 · Cooling 69
  3. 3ZSOV-36HDM-USwith ducted air handler ZAV-36HDM-USZERO3 tons · 36,000 Btu/h · DuctedNot a cold-climate pick: keeps 63% of its heat at 5°FMeets none of the standards tracked here
    Heat kept at 5°F
    63% (Capacity at 5°F vs 47°F)
    Below the middle
    Efficiency at 5°F
    2.06 (COP at 5°F)
    Great
    Winter efficiency
    9.0 (HSPF2)
    Good
    Cooling efficiency
    15.4 (SEER2)
    Below the middle
    Hot-day cooling
    8.2 (EER2)
    Below the middle
    42.3score / 100Heating 62 · Cooling 22

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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