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.

Panasonic 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, Panasonic scores higher on 5 of the 6 ratings.

Panasonic
Wells
Other ranked manufacturers

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

Average peer percentile, raw median and rank among ranked manufacturers
Rating	Panasonic	Wells
Efficiency index	68% (higher)median —	63% (higher)median —
COP at 5°F	64%median 2.00	64%median 2.10
Capacity retention at 5°F	72% (higher)median 90%	61% (higher)median 75%
HSPF2	80% (higher)median 10.3	74% (higher)median 10.0
SEER2	66% (higher)median 20.0	62% (higher)median 19.4
EER2	62% (higher)median 12.0	59% (higher)median 12.0
Heating capacity at 5°F	74% (higher)median 21,600 Btu/h	62% (higher)median 19,000 Btu/h
Outdoor models	29	37
AHRI certifications	277	121

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
Standard	Panasonic	Wells
CEE 2025 Tier 1 (Split ASHP)	96.6%28 models	86.5%32 models
CEE 2026 Tier 1 (Split ASHP)	96.6%28 models	83.8%31 models
CEE Advanced Tier (Split ASHP)	20.7%6 models	2.7%1 models
Xcel Energy Colorado cold-climate ASHP (2025)	89.7%26 models	81.1%30 models
DOE Cold Climate Heat Pump Challenge	20.7%6 models	2.7%1 models
ENERGY STAR Cold Climate	79.3%23 models	83.8%31 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

Panasonic
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	Panasonic	Wells
Ducted, up to 1.5 tons	6 · index 68%	9 · index 80%
Ducted, 2 tons	3 · index 64%	5 · index 73%
Ducted, 2.5–3 tons	6 · index 64%	7 · index 67%
Ducted, 3.5–4.5 tons	5 · index 52%	7 · index 63%
Ducted, 5 tons and up	None	1 · index 63%
Non-ducted, up to 1.5 tons	9 · index 81%	16 · index 58%
Non-ducted, 2 tons	4 · index 76%	4 · index 53%
Non-ducted, 2.5–3 tons	3 · index 57%	4 · index 54%
Non-ducted, 3.5–4.5 tons	1 · index 63%	3 · index 57%
Non-ducted, 5 tons and up	None	1 · index 27%

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	PanasonicCold-climate score, best model	WellsCold-climate score, best model
Ducted, up to 1.5 tons	80.1(50 is the typical model of its size class)CU-YM9CBUCwith ducted air handler CS-YM9CD2UW5 of 6 models qualify · AHRI 218027968	93.5(50 is the typical model of its size class) (higher)WOS-06PRE/230with ducted air handler WIDL-06MOC/2309 of 9 models qualify · AHRI 215864077
Ducted, 2 tons	77.1(50 is the typical model of its size class)CU-YM24CBUCwith ducted air handler CS-YM24CD1UW3 of 3 models qualify · AHRI 218027971	85.7(50 is the typical model of its size class) (higher)WOS-24PRE/230with ducted air handler WIDH-24MOC/2305 of 5 models qualify · AHRI 215864084
Ducted, 2.5–3 tons	83.1(50 is the typical model of its size class) (higher)CU-5YM36CBUC5 of 6 models qualify · AHRI 218027980	82.5(50 is the typical model of its size class)WOM-36HH5/2307 of 7 models qualify · AHRI 215864112
Ducted, 3.5–4.5 tons	82.7(50 is the typical model of its size class)CU-6YM48CBUC5 of 5 models qualify · AHRI 218027983	82.7(50 is the typical model of its size class)WOM-48HH6/2307 of 7 models qualify · AHRI 215864115
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	94.9(50 is the typical model of its size class) (higher)CU-XZ9AKUACwith ductless indoor unit CS-XZ9AKUAW9 of 9 models qualify · AHRI 214837752	94.4(50 is the typical model of its size class)WOS-06PRE/230with ductless indoor unit WI1C-06MOC/23011 of 16 models qualify · AHRI 215864073
Non-ducted, 2 tons	90.9(50 is the typical model of its size class) (higher)CU-3Z22ABUC4 of 4 models qualify · AHRI 214837935	89.4(50 is the typical model of its size class)WOS-24PRE/230with ductless indoor unit WI4C-24MOC/2304 of 4 models qualify · AHRI 215864072
Non-ducted, 2.5–3 tons	73.0(50 is the typical model of its size class) (higher)CU-5YM36CBUC3 of 3 models qualify · AHRI 218027981	72.6(50 is the typical model of its size class)WOM-36HH5/2304 of 4 models qualify · AHRI 215864113
Non-ducted, 3.5–4.5 tons	68.7(50 is the typical model of its size class)CU-6YM48CBUC1 of 1 models qualify · AHRI 218027984	69.9(50 is the typical model of its size class) (higher)WOM-60HH6/2303 of 3 models qualify · AHRI 215864119
Non-ducted, 5 tons and up	No models in this size class	None on this board (0 of 1 models qualify)

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	PanasonicAll-around score, best model	WellsAll-around score, best model
Ducted, up to 1.5 tons	78.4(50 is the typical model of its size class)CU-YM18CBUCwith ducted air handler CS-YM18CD1UW6 of 6 models have all five ratings · AHRI 218027970	95.0(50 is the typical model of its size class) (higher)WOS-06PRE/230with ducted air handler WIDL-06MOC/2309 of 9 models have all five ratings · AHRI 215864077
Ducted, 2 tons	78.8(50 is the typical model of its size class)CU-YM24CBUCwith ducted air handler CS-YM24CD1UW3 of 3 models have all five ratings · AHRI 218027971	79.6(50 is the typical model of its size class) (higher)WDHP-2436T-Gwith ducted air handler WDAH-24MOC-G5 of 5 models have all five ratings · AHRI 217048501
Ducted, 2.5–3 tons	84.0(50 is the typical model of its size class) (higher)CU-5YM36CBUC6 of 6 models have all five ratings · AHRI 218027980	83.6(50 is the typical model of its size class)WOM-36HH5/2307 of 7 models have all five ratings · AHRI 215864112
Ducted, 3.5–4.5 tons	83.9(50 is the typical model of its size class)CU-6YM48CBUC5 of 5 models have all five ratings · AHRI 218027983	85.1(50 is the typical model of its size class) (higher)WOM-48RH6/2307 of 7 models have all five ratings · AHRI 215864100
Ducted, 5 tons and up	No models in this size class	62.5(50 is the typical model of its size class)WOM-60RH6/2301 of 1 models have all five ratings · AHRI 215864103
Non-ducted, up to 1.5 tons	95.9(50 is the typical model of its size class) (higher)CU-XZ9AKUACwith ductless indoor unit CS-XZ9AKUAW9 of 9 models have all five ratings · AHRI 214837752	93.8(50 is the typical model of its size class)WOS-06PRE/230with ductless indoor unit WIHW-06MOC/23016 of 16 models have all five ratings · AHRI 215864044
Non-ducted, 2 tons	87.8(50 is the typical model of its size class) (higher)CU-4Z24BBUC4 of 4 models have all five ratings · AHRI 216441721	74.3(50 is the typical model of its size class)WOS-24QUA/230with ductless indoor unit WIHW-24MOC/2304 of 4 models have all five ratings · AHRI 215864043
Non-ducted, 2.5–3 tons	66.3(50 is the typical model of its size class)CU-5YM36CBUC3 of 3 models have all five ratings · AHRI 218027979	66.3(50 is the typical model of its size class)WOM-36HH5/2304 of 4 models have all five ratings · AHRI 215864111
Non-ducted, 3.5–4.5 tons	62.9(50 is the typical model of its size class) (higher)CU-6YM48CBUC1 of 1 models have all five ratings · AHRI 218027982	62.6(50 is the typical model of its size class)WOM-60HH6/2303 of 3 models have all five ratings · AHRI 215864117
Non-ducted, 5 tons and up	No models in this size class	32.5(50 is the typical model of its size class)WOM-60RH6/2301 of 1 models have all five ratings · AHRI 215864102

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	Panasonic	Wells
COP at 5°F	beats 99% · 2.51CU-YM12CBUCNon-ducted, up to 1.5 tons	beats 99% · 2.51WOS-12QUA/230Non-ducted, up to 1.5 tons
Capacity retention at 5°F	beats 99% · 134%CU-XZ9AKUACNon-ducted, up to 1.5 tons	beats 98% · 126%WOS-09PRE/230Non-ducted, up to 1.5 tons
HSPF2	beats 99% · 11.0CU-6YM48CBUCDucted, 3.5–4.5 tons	beats 99% · 11.0WOM-48HH6/230Ducted, 3.5–4.5 tons
SEER2	beats 96% · 27.5CU-XZ9AKUACNon-ducted, up to 1.5 tons	beats 96% · 20.4WOM-48RH6/230Ducted, 3.5–4.5 tons
EER2	beats 97% · 16.4CU-XZ9AKUACNon-ducted, up to 1.5 tons	beats 99% · 14.4WOS-06PRE/230Ducted, up to 1.5 tons
Heating capacity at 5°F	beats 99% · 22,000 Btu/hCU-2Z18ABUCNon-ducted, up to 1.5 tons	beats 97% · 39,000 Btu/hWDHP-36HHDucted, 2.5–3 tons

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Panasonic vs Wells heat pumps