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.

KERR 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, KERR scores higher on 6 of the 6 ratings.

KERR
Wells
Other ranked manufacturers

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

Average peer percentile, raw median and rank among ranked manufacturers
Rating	KERR	Wells
Efficiency index	66% (higher)median —	57% (higher)median —
COP at 5°F	49% (higher)median 1.95	40% (higher)median 1.85
Capacity retention at 5°F	78% (higher)median 91%	60% (higher)median 79%
HSPF2	76% (higher)median 10.0	70% (higher)median 9.5
SEER2	68% (higher)median 20.0	65% (higher)median 20.2
EER2	58% (higher)median 11.9	50% (higher)median 11.0
Heating capacity at 5°F	75% (higher)median 25,000 Btu/h	59% (higher)median 23,000 Btu/h
Outdoor models	24	35
AHRI certifications	90	70

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
Standard	KERR	Wells
CEE 2025 Tier 1 (Split ASHP)	83.3%20 models	74.3%26 models
CEE 2026 Tier 1 (Split ASHP)	83.3%20 models	68.6%24 models
CEE Advanced Tier (Split ASHP)	8.3%2 models	0%0 models
Xcel Energy Colorado cold-climate ASHP (2025)	79.2%19 models	60%21 models
DOE Cold Climate Heat Pump Challenge	8.3%2 models	0%0 models
ENERGY STAR Cold Climate	87.5%21 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 · 8 groups where both have models

KERR
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	KERR	Wells
Ducted, up to 1.5 tons	6 · index 60%	2 · index 59%
Ducted, 2 tons	3 · index 71%	1 · index 53%
Ducted, 2.5–3 tons	5 · index 67%	9 · index 62%
Ducted, 3.5–4.5 tons	4 · index 63%	8 · index 58%
Ducted, 5 tons and up	None	1 · index 57%
Non-ducted, up to 1.5 tons	7 · index 68%	11 · index 56%
Non-ducted, 2 tons	3 · index 79%	2 · index 49%
Non-ducted, 2.5–3 tons	6 · index 64%	7 · index 57%
Non-ducted, 3.5–4.5 tons	2 · index 65%	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	KERRCold-climate score, best model	WellsCold-climate score, best model
Ducted, up to 1.5 tons	74.9(50 is the typical model of its size class) (higher)A-KMH09SV-1with ducted air handler B-KMH09DU-16 of 6 models qualify · AHRI 210568255	52.0(50 is the typical model of its size class)WMMA-18HFMO2 of 2 models qualify · AHRI 213286761
Ducted, 2 tons	79.4(50 is the typical model of its size class) (higher)A-KMH24SU-1Awith ducted air handler B-KMH24DU-1Also listed as A-KMH24SV-13 of 3 models qualify · AHRI 206347321	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	79.9(50 is the typical model of its size class)A-KMH36QV-1A5 of 5 models qualify · AHRI 217169741	80.4(50 is the typical model of its size class) (higher)WMCA-27HFMO7 of 9 models qualify · AHRI 213286779
Ducted, 3.5–4.5 tons	74.9(50 is the typical model of its size class)A-KMH48PV-14 of 4 models qualify · AHRI 207657607	74.9(50 is the typical model of its size class)WMCA-48HFMO5 of 8 models qualify · AHRI 213286782
Ducted, 5 tons and up	No models in this size class	None on this board (0 of 1 models qualify)
Non-ducted, up to 1.5 tons	89.3(50 is the typical model of its size class) (higher)A-KMH06SV-1with ductless indoor unit B-KMH06SV-17 of 7 models qualify · AHRI 207657393	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	86.1(50 is the typical model of its size class) (higher)A-KMH24SV-1with ductless indoor unit C-VMH24CV-13 of 3 models qualify · AHRI 207657400	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	90.9(50 is the typical model of its size class) (higher)A-KMH36QV-1A3 of 6 models qualify · AHRI 217169740	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	76.2(50 is the typical model of its size class)A-KMH48PV-12 of 2 models qualify · AHRI 207657606	80.5(50 is the typical model of its size class) (higher)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	KERRAll-around score, best model	WellsAll-around score, best model
Ducted, up to 1.5 tons	85.2(50 is the typical model of its size class) (higher)A-KMH09SV-1with ducted air handler B-KMH09DU-16 of 6 models have all five ratings · AHRI 210568255	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	80.1(50 is the typical model of its size class) (higher)A-KMH24SU-1Awith ducted air handler B-KMH24DU-1Also listed as A-KMH24SV-13 of 3 models have all five ratings · AHRI 206347321	65.8(50 is the typical model of its size class)WUCA-24HFMOwith ducted air handler WUA-24HFMAH1 of 1 models have all five ratings · AHRI 213307899
Ducted, 2.5–3 tons	83.7(50 is the typical model of its size class)A-KMH36QV-1A5 of 5 models have all five ratings · AHRI 217169741	83.7(50 is the typical model of its size class)WMCA-36HFMO9 of 9 models have all five ratings · AHRI 213307897
Ducted, 3.5–4.5 tons	82.0(50 is the typical model of its size class)A-KMH48PV-14 of 4 models have all five ratings · AHRI 207657607	82.0(50 is the typical model of its size class)WMCA-48HFMO8 of 8 models have all five ratings · AHRI 213286782
Ducted, 5 tons and up	No models in this size class	57.1(50 is the typical model of its size class)WSMA-60HFMOwith ducted air handler WSMA-60HFMD1 of 1 models have all five ratings · AHRI 214797744
Non-ducted, up to 1.5 tons	92.0(50 is the typical model of its size class) (higher)A-KMH06SV-1with ductless indoor unit B-KMH06SV-17 of 7 models have all five ratings · AHRI 207657393	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	84.3(50 is the typical model of its size class) (higher)A-KMH24SV-1with ductless indoor unit B-KMH24SV-1Also listed as A-KMH24SU-13 of 3 models have all five ratings · AHRI 207657397	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	86.4(50 is the typical model of its size class) (higher)A-KMH36QV-1A5 of 6 models have all five ratings · AHRI 217169740	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	77.9(50 is the typical model of its size class) (higher)A-KMH48PV-12 of 2 models have all five ratings · AHRI 207657606	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	KERR	Wells
COP at 5°F	beats 91% · 2.21A-KMH24SV-1Also listed as A-KMH24SU-1Non-ducted, 2 tons	beats 83% · 2.16WSB-09HFBONon-ducted, up to 1.5 tons
Capacity retention at 5°F	beats 98% · 112%A-KCD36SA-1Ducted, 2.5–3 tons	beats 96% · 101%WMCA-27HFMODucted, 2.5–3 tons
HSPF2	beats 98% · 13.6A-KMH06SV-1Non-ducted, up to 1.5 tons	beats 97% · 10.9WMCA-36HFMONon-ducted, 2.5–3 tons
SEER2	beats 99% · 20.9A-KMH48PV-1Ducted, 3.5–4.5 tons	beats 99% · 20.9WMCA-48HFMODucted, 3.5–4.5 tons
EER2	beats 98% · 16.2A-KMH09SV-1Non-ducted, up to 1.5 tons	beats 95% · 15.8WSA-09HFMONon-ducted, up to 1.5 tons
Heating capacity at 5°F	beats 99% · 42,000 Btu/hA-KCD36SA-1Ducted, 2.5–3 tons	beats 96% · 20,000 Btu/hWMCA-18HFMONon-ducted, up to 1.5 tons

More comparisons

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KERR vs Wells heat pumps