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SUM X heat pumps: how do their ratings compare?

A typical SUM X heat pump beats 73% of similar heat pumps (same size and type), which is well above average. SUM X has 6 heat pump models in this list.

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

Overall score

73%

of similar heat pumps beaten by its typical model

Well above average

SUM X has no QMID (the manufacturer ID the 25C tax credit needs) on file, so it is not ranked against other brands. Based on 6 models with every rating.

SUM X, rating by ratingStrongest on heating power kept at 5°f (beats 80%), weakest on hot-day cooling efficiency (beats 61%).
  • Efficiency on a 5°F dayCOP at 5°FBeats 78%
  • Heating power kept at 5°FCapacity at 5°F vs 47°FBeats 80%
  • Winter-long heating efficiencyHSPF2Beats 70%
  • Summer-long cooling efficiencySEER2Beats 79%
  • Hot-day cooling efficiencyEER2Beats 61%

Average (50%)

Each bar: the share of similar heat pumps a typical model beats on that rating.

Want SUM X’s ranks and its models inside every size class? Switch to Advanced

Rebate standards

Share of this brand’s models that meet the efficiency levels rebate programs use. Programs can have other rules too.

  • 100%

    meet CEE 2025 Tier 1, the level many utility rebates use.

    6 models. All brands: 57%.

    See them

  • 100%

    meet Xcel Energy Colorado’s cold-climate rebate levels.

    6 models. All brands: 53%.

    See them

  • 0%

    reach the cold-climate tier: full heating output and a COP of 2.1 or more at 5°F.

    None of its models yet. All brands: 3%.

Top SUM X cold-climate picks, by size

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

2 of SUM X’s 2 models of this size and type qualify.

  1. 1SM-12HSM2-CUwith ductless indoor unit SM-12HSM2-WUSUM X1 ton · 12,000 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
    2.00 (COP at 5°F)
    Good
    Seasonal efficiency
    9.5 (HSPF2)
    Below the middle
    60.1score / 100
  2. 2SM-18HSM2-CUwith ductless indoor unit SM-18HSM2-WUSUM X1.5 tons · 18,000 Btu/h · DuctlessKeeps 100% of its heat at 5°FMeets 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
    1.90 (COP at 5°F)
    Below the middle
    Seasonal efficiency
    9.5 (HSPF2)
    Below the middle
    58.5score / 100

These are certified test ratings, not a recommendation for your home. The right size comes from a load calculation by a contractor.

What to do next

The advanced view has SUM X’s ranks on each rating, its models inside every size and type, cold-weather curves and its newest certifications.

Open the advanced view