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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%

Top cold-climate picks, ductless 2 tons

Only units that keep at least 70% of their heat at 5°F, ranked on heat kept, efficiency at 5°F and seasonal efficiency (HSPF2), against units their size.

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

COMFORTSTAR

  1. 1CHF24CD(O)with ductless indoor unit TIP-24COMFORTSTAR2 tons · 24,000 Btu/h · DuctlessKeeps 103% of its heat at 5°FMeets CEE 2025, CEE 2026, CEE Advanced, Xcel CC, DOE CCHP, ENERGY STAR CC
    Heat kept at 5°F
    103% (Capacity at 5°F vs 47°F)
    Top 10%
    Efficiency at 5°F
    2.00 (COP at 5°F)
    Good
    Seasonal efficiency
    11.5 (HSPF2)
    Top 10%
    86.1score / 100
  2. 2CZP24CD(O)with ductless indoor unit FPA-24COMFORTSTAR2 tons · 24,000 Btu/h · DuctlessKeeps 76% of its heat at 5°FMeets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    76% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    2.20 (COP at 5°F)
    Great
    Seasonal efficiency
    10.3 (HSPF2)
    Great
    74.2score / 100

ZERO

  1. 1ZSOV-24HDM-USwith ductless indoor unit ZEV-24HDM-USZERO2 tons · 24,000 Btu/h · DuctlessKeeps 76% of its heat at 5°FMeets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    76% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    2.20 (COP at 5°F)
    Great
    Seasonal efficiency
    10.3 (HSPF2)
    Great
    74.2score / 100
  2. 2ZMSB-24HV-USHHCwith ductless indoor unit ZMSB-24HV-USHHCZEROAlso listed as ZMSB-24HV-USHHC-O2 tons · 23,000 Btu/h · DuctlessKeeps 88% of its heat at 5°FMeets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    88% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    1.80 (COP at 5°F)
    Below the middle
    Seasonal efficiency
    10.3 (HSPF2)
    Great
    61.1score / 100
  3. 3ZMSB-24HV-USHHwith ductless indoor unit ZMSB-24HV-USHHZERO2 tons · 24,000 Btu/h · DuctlessKeeps 75% of its heat at 5°FMeets CEE 2025, CEE 2026, Xcel CC
    Heat kept at 5°F
    75% (Capacity at 5°F vs 47°F)
    Below the middle
    Efficiency at 5°F
    2.22 (COP at 5°F)
    Top 10%
    Seasonal efficiency
    8.5 (HSPF2)
    Below the middle
    55.7score / 100

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