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MAXI AIR vs MSH LEGACY heat pumps

Measured against models of the same size and duct type, MAXI AIR scores higher on 6 of the 6 ratings. MAXI AIR has 10 outdoor models, MSH LEGACY has 7 outdoor models. MAXI AIR and MSH LEGACY 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.
MAXI AIR and MSH LEGACY 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, MAXI AIR scores higher on 6 of the 6 ratings.
  • MAXI AIR
  • MSH LEGACY
  • Other ranked manufacturers
MAXI AIRMSH LEGA…

Source: AHRI Directory, NEEP · as of

Average peer percentile, raw median and rank among ranked manufacturers
RatingMAXI AIRMSH LEGACY
Efficiency index75% (higher)median —34% (higher)median —
COP at 5°F51% (higher)median 2.0025% (higher)median 1.80
Capacity retention at 5°F83% (higher)median 98%11% (higher)median 41%
HSPF283% (higher)median 10.524% (higher)median 7.2
SEER277% (higher)median 23.039% (higher)median 15.2
EER277% (higher)median 12.856% (higher)median 11.5
Heating capacity at 5°F84% (higher)median 27,000 Btu/h15% (higher)median 18,200 Btu/h
Outdoor models107
AHRI certifications347

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
StandardMAXI AIRMSH LEGACY
CEE 2025 Tier 1 (Split ASHP)100%10 models0%0 models
CEE 2026 Tier 1 (Split ASHP)100%10 models0%0 models
CEE Advanced Tier (Split ASHP)0%0 models0%0 models
Xcel Energy Colorado cold-climate ASHP (2025)100%10 models0%0 models
DOE Cold Climate Heat Pump Challenge0%0 models0%0 models
ENERGY STAR Cold Climate70%7 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 · 2 groups where both have models
  • MAXI AIR
  • MSH LEGACY
  • 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, 2.5–3 tons2.001,106 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 typeMAXI AIRMSH LEGACY
Ducted, up to 1.5 tons2 · index 77%None
Ducted, 2.5–3 tons5 · index 77%2 · index 27%
Ducted, 3.5–4.5 tons1 · index 49%4 · index 40%
Ducted, 2 tonsNone1 · index 21%
Non-ducted, up to 1.5 tons4 · index 75%None
Non-ducted, 2.5–3 tons4 · index 76%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 typeMAXI AIRCold-climate score, best modelMSH LEGACYCold-climate score, best model
Ducted, up to 1.5 tons70.8(50 is the typical model of its size class)T55-MULTI18E454Also listed as T55-MULTI18E4542 of 2 models qualify · AHRI 218381880No models in this size class
Ducted, 2 tonsNo models in this size classNone on this board (0 of 1 models qualify)
Ducted, 2.5–3 tons82.5(50 is the typical model of its size class)T55-MULTI36E454Also listed as T55-MULTI36E4545 of 5 models qualify · AHRI 217752780None on this board (0 of 2 models qualify)
Ducted, 3.5–4.5 tons60.5(50 is the typical model of its size class)MAXS-4260-454with ducted air handler AHMS-6020-4541 of 1 models qualify · AHRI 217752767None on this board (0 of 4 models qualify)
Non-ducted, up to 1.5 tons73.8(50 is the typical model of its size class)T55-AES18EXT454with ductless indoor unit T55-AES18INT4544 of 4 models qualify · AHRI 217752773No models in this size class
Non-ducted, 2.5–3 tons78.0(50 is the typical model of its size class)T55-MULTI36E454Also listed as T55-MULTI36E4544 of 4 models qualify · AHRI 217752781No 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 typeMAXI AIRAll-around score, best modelMSH LEGACYAll-around score, best model
Ducted, up to 1.5 tons77.4(50 is the typical model of its size class)T55-MULTI18E454Also listed as T55-MULTI18E4542 of 2 models have all five ratings · AHRI 218381880No models in this size class
Ducted, 2 tonsNo models in this size class20.5(50 is the typical model of its size class)PHB524000K000B*1 of 1 models have all five ratings · AHRI 217154396
Ducted, 2.5–3 tons83.6(50 is the typical model of its size class) (higher)T55-MULTI36E454Also listed as T55-MULTI36E4545 of 5 models have all five ratings · AHRI 21775278027.2(50 is the typical model of its size class)PHB536000H000B*2 of 2 models have all five ratings · AHRI 217154420
Ducted, 3.5–4.5 tons49.1(50 is the typical model of its size class) (higher)MAXS-4260-454with ducted air handler AHMS-6020-4541 of 1 models have all five ratings · AHRI 21775276746.0(50 is the typical model of its size class)PHB560000H000B*4 of 4 models have all five ratings · AHRI 217154470
Non-ducted, up to 1.5 tons81.9(50 is the typical model of its size class)T55-MULTI18E454Also listed as T55-MULTI18E4544 of 4 models have all five ratings · AHRI 218381879No models in this size class
Non-ducted, 2.5–3 tons78.3(50 is the typical model of its size class)T55-MULTI36E454Also listed as T55-MULTI36E4544 of 4 models have all five ratings · AHRI 217752779No 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
RatingMAXI AIRMSH LEGACY
COP at 5°Fbeats 63% · 2.00T55-MULTI18E454Also listed as T55-MULTI18E454Ducted, up to 1.5 tonsbeats 54% · 2.00PHB560000K000B*Ducted, 3.5–4.5 tons
Capacity retention at 5°Fbeats 97% · 107%MAXS-2430-454Ducted, 2.5–3 tonsbeats 17% · 46%PHB560000H000B*Ducted, 3.5–4.5 tons
HSPF2beats 94% · 10.4T55-MULTI36E454Also listed as T55-MULTI36E454Ducted, 2.5–3 tonsbeats 34% · 7.7PHB560000K000B*Ducted, 3.5–4.5 tons
SEER2beats 88% · 25.4T55-AES12EXT454Non-ducted, up to 1.5 tonsbeats 42% · 15.5PHB560000K000B*Ducted, 3.5–4.5 tons
EER2beats 91% · 15.0T55-MULTI18E454Also listed as T55-MULTI18E454Non-ducted, up to 1.5 tonsbeats 57% · 11.5PHB548000K000B*Ducted, 3.5–4.5 tons
Heating capacity at 5°Fbeats 97% · 19,000 Btu/hT55-MULTI18E454Also listed as T55-MULTI18E454Non-ducted, up to 1.5 tonsbeats 27% · 25,800 Btu/hPHB560000K000B*Ducted, 3.5–4.5 tons

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