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RUSSELL vs ZERO: heat pump ratings compared

Against heat pumps of the same size and type, a typical RUSSELL model beats 33% and a typical ZERO model 53%. ZERO rates higher overall.

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

RUSSELL

33%

of similar heat pumps beaten by its typical model

Well below average

111 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°FRUSSELL: Beats 37%ZERO: Beats 45%
  • Heating power kept at 5°FCapacity at 5°F vs 47°FRUSSELL: Beats 21%ZERO: Beats 52%
  • Winter-long heating efficiencyHSPF2RUSSELL: Beats 24%ZERO: Beats 57%
  • Summer-long cooling efficiencySEER2RUSSELL: Beats 28%ZERO: Beats 58%
  • Hot-day cooling efficiencyEER2RUSSELL: Beats 36%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

    RUSSELL
    11%
    ZERO
    71%
  • Xcel CC

    RUSSELL
    7%
    ZERO
    65%
  • CEE Advanced

    RUSSELL
    0%
    ZERO
    0%
  • ENERGY STAR CC

    RUSSELL
    12%
    ZERO
    53%

Top cold-climate picks, ductless 2.5–3 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.

RUSSELL

No ductless, 2.5–3 tons model from RUSSELL.

ZERO

  1. 1Z4SOV-36HDMB-USHHZERO3 tons · 36,000 Btu/h · DuctlessKeeps 104% of its heat at 5°FMeets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    104% (Capacity at 5°F vs 47°F)
    Top 10%
    Efficiency at 5°F
    1.95 (COP at 5°F)
    Below the middle
    Seasonal efficiency
    10.9 (HSPF2)
    Top 10%
    72.6score / 100
  2. 2Z3SOV-27HDTB-USZERO2.5 tons · 27,000 Btu/h · DuctlessKeeps 71% of its heat at 5°FMeets 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
    2.00 (COP at 5°F)
    Good
    Seasonal efficiency
    10.5 (HSPF2)
    Great
    57.5score / 100
  3. 3ZMSB-33HV-USHHCR2-Owith ductless indoor unit ZMSB-33HV-USHHCR2-IZERO3 tons · 33,000 Btu/h · DuctlessKeeps 96% of its heat at 5°FMeets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    96% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    1.91 (COP at 5°F)
    Below the middle
    Seasonal efficiency
    10.5 (HSPF2)
    Great
    56.5score / 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