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AIR C vs Legacy Systems heat pumps

Measured against models of the same size and duct type, AIR C scores higher on 5 of the 6 ratings. AIR C has 11 outdoor models, Legacy Systems has 11 outdoor models. AIR C and Legacy Systems have no QMID on file and are not ranked.

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CompareData as of updated · sources

Against comparable models

Each cell is the share of same-size, same-type models that the manufacturer’s typical model beats (50% is typical); the higher score is in bold. Raw medians are underneath for context: they depend on which sizes each one makes, so they are not compared.
AIR C and Legacy Systems on every ratingPeer scores, 0–100 · grey ticks: every ranked manufacturer · shaded: the middle half of each one’s modelsMeasured against models of the same size and duct type, AIR C scores higher on 5 of the 6 ratings.
  • AIR C
  • Legacy Systems
  • Other ranked manufacturers
AIR CLegacy S…

Source: AHRI Directory, NEEP · as of

Average peer percentile, raw median and rank among ranked manufacturers
RatingAIR CLegacy Systems
Efficiency index78% (higher)median —44% (higher)median —
COP at 5°F60% (higher)median 2.0040% (higher)median 1.90
Capacity retention at 5°F85% (higher)median 100%17% (higher)median 50%
HSPF288% (higher)median 10.932% (higher)median 7.8
SEER281% (higher)median 23.031% (higher)median 15.0
EER279%median 13.087%median 12.5
Heating capacity at 5°F83% (higher)median 22,600 Btu/h23% (higher)median 14,400 Btu/h
Outdoor models1111
AHRI certifications21799

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
StandardAIR CLegacy Systems
CEE 2025 Tier 1 (Split ASHP)90.9%10 models0%0 models
CEE 2026 Tier 1 (Split ASHP)90.9%10 models0%0 models
CEE Advanced Tier (Split ASHP)0%0 models0%0 models
Xcel Energy Colorado cold-climate ASHP (2025)100%11 models0%0 models
DOE Cold Climate Heat Pump Challenge0%0 models0%0 models
ENERGY STAR Cold Climate0%0 models0%0 models

Sizes and duct types offered

Models in each peer group, with the efficiency index of those models against the rest of the group.
Side by side, inside each size and duct typeShape: every model of the group · bars: each manufacturer’s middle half, median dot, 10th–90th line · 3 groups where both have models
  • AIR C
  • Legacy Systems
  • All models of the group
Ducted, up to 1.5 tons1.901,783 modelsDucted, 2 tons2.001,090 modelsDucted, 2.5–3 tons2.001,909 modelsDucted, 3.5–4.5 tons2.002,224 modelsNon-ducted, up to 1.5 tons1.953,455 modelsNon-ducted, 2 tons2.00863 modelsNon-ducted, 2.5–3 tons2.001,106 modelsNon-ducted, 3.5–4.5 tons2.00564 modelsmedian

Raw ratings are only placed side by side within one size and duct type, where they are comparable.

Source: AHRI Directory · as of

Models per peer group · efficiency index within the group
Size and duct typeAIR CLegacy Systems
Ducted, up to 1.5 tons1 · index 77%2 · index 38%
Ducted, 2.5–3 tons2 · index 81%4 · index 46%
Ducted, 3.5–4.5 tons2 · index 83%3 · index 52%
Ducted, 2 tonsNone2 · index 35%
Non-ducted, up to 1.5 tons6 · index 80%None
Non-ducted, 2 tons1 · index 77%None
Non-ducted, 2.5–3 tons2 · index 76%None
Non-ducted, 3.5–4.5 tons2 · index 68%None

Cold-climate and all-around picks, size class by size class

Each manufacturer’s best model on each board in every size and duct type, side by side; the higher score is in bold. Both scores are 0–100 against every model of that size class (the line on each bar is 50, the typical model there), so the two compare fairly even when they make different sizes.

Cold-climate picks

Best cold-climate pick per size and duct type (keeps at least 70% of its heat at 5°F). Qualifies when its capacity retention at 5°F (capacity at 5°F as a share of capacity at 47°F) is at least 70% and Capacity retention at 5°F, COP at 5°F, HSPF2 are all rated. Score = the equal-weight mean of its peer percentiles on Capacity retention at 5°F, COP at 5°F, HSPF2 (share of the other models in its peer group it beats, 0–100), all from one certified pairing: in each duct type a model is sold in, its qualifying pairing of that type with the best score; equal scores (one decimal) go to the higher heating capacity at 5°F.
Size and duct typeAIR CCold-climate score, best modelLegacy SystemsCold-climate score, best model
Ducted, up to 1.5 tons70.8(50 is the typical model of its size class)UE-H18M1P1 of 1 models qualify · AHRI 215461325None on this board (0 of 2 models qualify)
Ducted, 2 tonsNo models in this size classNone on this board (0 of 2 models qualify)
Ducted, 2.5–3 tons83.1(50 is the typical model of its size class)UE-H36M1P2 of 2 models qualify · AHRI 215461336None on this board (0 of 4 models qualify)
Ducted, 3.5–4.5 tons82.7(50 is the typical model of its size class)UE-H48M1P2 of 2 models qualify · AHRI 215461341None on this board (0 of 3 models qualify)
Non-ducted, up to 1.5 tons85.9(50 is the typical model of its size class)UE-SH09S1Pwith ductless indoor unit UI-SH09MS1P5 of 6 models qualify · AHRI 215461312No models in this size class
Non-ducted, 2 tons89.2(50 is the typical model of its size class)UE-H24S1Pwith ductless indoor unit UI-H24MS1P1 of 1 models qualify · AHRI 215461321No models in this size class
Non-ducted, 2.5–3 tons78.0(50 is the typical model of its size class)UE-H36M1P2 of 2 models qualify · AHRI 215461338No models in this size class
Non-ducted, 3.5–4.5 tons73.5(50 is the typical model of its size class)UE-H48M1P2 of 2 models qualify · AHRI 215461343No models in this size class

All-around best

Best all-around model per size and duct type. Score = 50% heating, the mean of its peer percentiles on COP at 5°F, Capacity retention at 5°F, HSPF2, plus 50% cooling, the mean of its peer percentiles on SEER2 and EER2 (share of the other models in its peer group it beats, 0–100). All five ratings are required; there is no minimum heat kept at 5°F. In each duct type a model is sold in, it is scored on its pairing of that type with the best score; equal scores (one decimal) go to the higher cold-climate score, then the higher heating capacity at 5°F.
Size and duct typeAIR CAll-around score, best modelLegacy SystemsAll-around score, best model
Ducted, up to 1.5 tons77.4(50 is the typical model of its size class) (higher)UE-H18M1P1 of 1 models have all five ratings · AHRI 21546132538.8(50 is the typical model of its size class)GLZS4MA1810A*with ducted air handler AMST24BU1300A2 of 2 models have all five ratings · AHRI 215233840
Ducted, 2 tonsNo models in this size class39.6(50 is the typical model of its size class)GLZS4MA2410A*with ducted air handler AMST24BU1300A2 of 2 models have all five ratings · AHRI 215233979
Ducted, 2.5–3 tons84.0(50 is the typical model of its size class) (higher)UE-H36M1P2 of 2 models have all five ratings · AHRI 21546133652.0(50 is the typical model of its size class)GLZS4MA3010A*with ducted air handler AWST30LU13**A4 of 4 models have all five ratings · AHRI 215234313
Ducted, 3.5–4.5 tons83.9(50 is the typical model of its size class) (higher)UE-H48M1P2 of 2 models have all five ratings · AHRI 21546134153.3(50 is the typical model of its size class)GLZS4BA6010A*with ducted air handler AMST60DU1300A3 of 3 models have all five ratings · AHRI 215233838
Non-ducted, up to 1.5 tons92.3(50 is the typical model of its size class)UE-SH09S1Pwith ductless indoor unit UI-SH09MS1P5 of 6 models have all five ratings · AHRI 215461312No models in this size class
Non-ducted, 2 tons76.8(50 is the typical model of its size class)UE-H24S1Pwith ductless indoor unit UI-H24MS1P1 of 1 models have all five ratings · AHRI 215461321No models in this size class
Non-ducted, 2.5–3 tons78.3(50 is the typical model of its size class)UE-H36M1P2 of 2 models have all five ratings · AHRI 215461334No models in this size class
Non-ducted, 3.5–4.5 tons76.2(50 is the typical model of its size class)UE-H48M1P2 of 2 models have all five ratings · AHRI 215461339No models in this size class

All-around board, every manufacturer

Standout model on each rating

Each manufacturer’s model that beats the largest share of comparable models on the rating; the higher share is in bold.
Top model per rating by peer percentile, with its AHRI-certified value and peer group
RatingAIR CLegacy Systems
COP at 5°Fbeats 94% · 2.34UE-SH18S1PNon-ducted, up to 1.5 tonsbeats 56% · 2.00GLZS4BA3010A*Ducted, 2.5–3 tons
Capacity retention at 5°Fbeats 96% · 113%UE-SH18S1PNon-ducted, up to 1.5 tonsbeats 23% · 53%GLZS4MA3010A*Ducted, 2.5–3 tons
HSPF2beats 99% · 11.0UE-H48M1PDucted, 3.5–4.5 tonsbeats 51% · 8.2GLZS4BA6010A*Ducted, 3.5–4.5 tons
SEER2beats 99% · 33.3UE-SH09S1PNon-ducted, up to 1.5 tonsbeats 35% · 15.2GLZS4BA4210A*Ducted, 3.5–4.5 tons
EER2beats 98% · 17.0UE-SH09S1PNon-ducted, up to 1.5 tonsbeats 93% · 12.5GLZS4BA4210A*Ducted, 3.5–4.5 tons
Heating capacity at 5°Fbeats 99% · 22,600 Btu/hUE-SH18S1PNon-ducted, up to 1.5 tonsbeats 46% · 8,700 Btu/hGLZS4BA1810A*Ducted, up to 1.5 tons

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