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.

IAIR and Wells 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, Wells scores higher on 5 of the 6 ratings.

IAIR
Wells
Other ranked manufacturers

Source: AHRI Directory, NEEP · as of Oct 11, 2026

Average peer percentile, raw median and rank among ranked manufacturers
Rating	IAIR	Wells
Efficiency index	18%median —	57%median —
COP at 5°F	2%median 1.40	40%median 1.85
Capacity retention at 5°F	4%median 36%	60%median 79%
HSPF2	19%median 7.5	70%median 9.5
SEER2	15%median 14.3	65%median 20.2
EER2	60% (higher)median 11.5	50% (higher)median 11.0
Heating capacity at 5°F	4%median 13,300 Btu/h	59%median 23,000 Btu/h
Outdoor models	35	35
AHRI certifications	103	70

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
Standard	IAIR	Wells
CEE 2025 Tier 1 (Split ASHP)	0%0 models	74.3%26 models
CEE 2026 Tier 1 (Split ASHP)	0%0 models	68.6%24 models
CEE Advanced Tier (Split ASHP)	0%0 models	0%0 models
Xcel Energy Colorado cold-climate ASHP (2025)	0%0 models	60%21 models
DOE Cold Climate Heat Pump Challenge	0%0 models	0%0 models
ENERGY STAR Cold Climate	0%0 models	60%21 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 · 5 groups where both have models

IAIR
Wells
All models of the group

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

Source: AHRI Directory · as of Oct 11, 2026

Models per peer group · efficiency index within the group
Size and duct type	IAIR	Wells
Ducted, up to 1.5 tons	3 · index —	2 · index 59%
Ducted, 2 tons	5 · index 12%	1 · index 53%
Ducted, 2.5–3 tons	10 · index 16%	9 · index 62%
Ducted, 3.5–4.5 tons	15 · index 21%	8 · index 58%
Ducted, 5 tons and up	2 · index 19%	1 · index 57%
Non-ducted, up to 1.5 tons	None	11 · index 56%
Non-ducted, 2 tons	None	2 · index 49%
Non-ducted, 2.5–3 tons	None	7 · index 57%
Non-ducted, 3.5–4.5 tons	None	4 · index 51%

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 type	IAIRCold-climate score, best model	WellsCold-climate score, best model
Ducted, up to 1.5 tons	None on this board (0 of 3 models qualify)	52.0(50 is the typical model of its size class)WMMA-18HFMO2 of 2 models qualify · AHRI 213286761
Ducted, 2 tons	None on this board (0 of 5 models qualify)	66.5(50 is the typical model of its size class)WUCA-24HFMOwith ducted air handler WUA-24HFMAH1 of 1 models qualify · AHRI 213307899
Ducted, 2.5–3 tons	None on this board (0 of 10 models qualify)	80.4(50 is the typical model of its size class)WMCA-27HFMO7 of 9 models qualify · AHRI 213286779
Ducted, 3.5–4.5 tons	None on this board (0 of 15 models qualify)	74.9(50 is the typical model of its size class)WMCA-48HFMO5 of 8 models qualify · AHRI 213286782
Ducted, 5 tons and up	None on this board (0 of 2 models qualify)	None on this board (0 of 1 models qualify)
Non-ducted, up to 1.5 tons	No models in this size class	74.8(50 is the typical model of its size class)WSA-09HFMOwith ductless indoor unit WSA-09HFMI7 of 11 models qualify · AHRI 214421469
Non-ducted, 2 tons	No models in this size class	61.1(50 is the typical model of its size class)WSA-24HFMOwith ductless indoor unit WSA-24HFMI1 of 2 models qualify · AHRI 214421472
Non-ducted, 2.5–3 tons	No models in this size class	87.0(50 is the typical model of its size class)WMCA-36HFMO4 of 7 models qualify · AHRI 213307896
Non-ducted, 3.5–4.5 tons	No models in this size class	80.5(50 is the typical model of its size class)WMCA-48HFMO2 of 4 models qualify · AHRI 213286781

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 type	IAIRAll-around score, best model	WellsAll-around score, best model
Ducted, up to 1.5 tons	None on this board (0 of 3 models have all five ratings)	59.4(50 is the typical model of its size class)WMMA-18HFMO2 of 2 models have all five ratings · AHRI 213286761
Ducted, 2 tons	12.4(50 is the typical model of its size class)APH3024E100AAlso listed as IPH3024E100A2 of 5 models have all five ratings · AHRI 211289991	65.8(50 is the typical model of its size class) (higher)WUCA-24HFMOwith ducted air handler WUA-24HFMAH1 of 1 models have all five ratings · AHRI 213307899
Ducted, 2.5–3 tons	17.3(50 is the typical model of its size class)APH3036E100AAlso listed as IPH3036E100A4 of 10 models have all five ratings · AHRI 212255584	83.7(50 is the typical model of its size class) (higher)WMCA-36HFMO9 of 9 models have all five ratings · AHRI 213307897
Ducted, 3.5–4.5 tons	21.5(50 is the typical model of its size class)APH3048E100AAlso listed as IPH3048E100A4 of 15 models have all five ratings · AHRI 212255588	82.0(50 is the typical model of its size class) (higher)WMCA-48HFMO8 of 8 models have all five ratings · AHRI 213286782
Ducted, 5 tons and up	19.3(50 is the typical model of its size class)APH3060E100AAlso listed as IPH3060E100A2 of 2 models have all five ratings · AHRI 212255589	57.1(50 is the typical model of its size class) (higher)WSMA-60HFMOwith ducted air handler WSMA-60HFMD1 of 1 models have all five ratings · AHRI 214797744
Non-ducted, up to 1.5 tons	No models in this size class	84.4(50 is the typical model of its size class)WSA-09HFMOwith ductless indoor unit WSA-09HFMI11 of 11 models have all five ratings · AHRI 214421469
Non-ducted, 2 tons	No models in this size class	70.7(50 is the typical model of its size class)WSA-24HFMOwith ductless indoor unit WSA-24HFMI2 of 2 models have all five ratings · AHRI 214421472
Non-ducted, 2.5–3 tons	No models in this size class	76.8(50 is the typical model of its size class)WMCA-36HFMO7 of 7 models have all five ratings · AHRI 213307896
Non-ducted, 3.5–4.5 tons	No models in this size class	73.8(50 is the typical model of its size class)WMCA-48HFMO4 of 4 models have all five ratings · AHRI 213286781

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
Rating	IAIR	Wells
COP at 5°F	beats 4% · 1.40APH3060E100AAlso listed as IPH3060E100ADucted, 5 tons and up	beats 83% · 2.16WSB-09HFBONon-ducted, up to 1.5 tons
Capacity retention at 5°F	beats 5% · 38%APH3060E100AAlso listed as IPH3060E100ADucted, 5 tons and up	beats 96% · 101%WMCA-27HFMODucted, 2.5–3 tons
HSPF2	beats 39% · 7.8AHP5042E1000AAlso listed as IHP5042E1000ADucted, 3.5–4.5 tons	beats 97% · 10.9WMCA-36HFMONon-ducted, 2.5–3 tons
SEER2	beats 40% · 15.2AHP5042E1000AAlso listed as IHP5042E1000ADucted, 3.5–4.5 tons	beats 99% · 20.9WMCA-48HFMODucted, 3.5–4.5 tons
EER2	beats 82% · 12.0AHP5042E1000AAlso listed as IHP5042E1000ADucted, 3.5–4.5 tons	beats 95% · 15.8WSA-09HFMONon-ducted, up to 1.5 tons
Heating capacity at 5°F	beats 11% · 21,600 Btu/hAPH3060E100AAlso listed as IPH3060E100ADucted, 5 tons and up	beats 96% · 20,000 Btu/hWMCA-18HFMONon-ducted, up to 1.5 tons

More comparisons

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IAIR vs Wells heat pumps