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.

AUX and Lennox 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, AUX scores higher on 4 of the 6 ratings.

AUX
Lennox
Other ranked manufacturers

Source: AHRI Directory, NEEP · as of Oct 25, 2026

Average peer percentile, raw median and rank among ranked manufacturers
Rating	AUX	Lennox
Efficiency index	49% (higher)median — · 21st ranked	48% (higher)median — · 24th ranked
COP at 5°F	60% (higher)median 2.00 · 7th ranked	46% (higher)median 1.95 · 22nd ranked
Capacity retention at 5°F	51% (higher)median 75% · 15th ranked	44% (higher)median 62% · 23rd ranked
HSPF2	40%median 9.0 · 25th ranked	44%median 8.1 · 21st ranked
SEER2	48% (higher)median 20.0 · 18th ranked	45% (higher)median 16.0 · 21st ranked
EER2	39%median 11.0 · 27th ranked	57%median 11.7 · 12th ranked
Heating capacity at 5°F	49% (higher)median 9,600 Btu/h · 17th ranked	45% (higher)median 19,000 Btu/h · 23rd ranked
Outdoor models	189	337
AHRI certifications	223	67,062

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
Standard	AUX	Lennox
CEE 2025 Tier 1 (Split ASHP)	68.3%129 models	43.6%147 models
CEE 2026 Tier 1 (Split ASHP)	66.1%125 models	41.2%139 models
CEE Advanced Tier (Split ASHP)	1.1%2 models	2.7%9 models
Xcel Energy Colorado cold-climate ASHP (2025)	65.6%124 models	35.9%121 models
DOE Cold Climate Heat Pump Challenge	1.1%2 models	2.7%9 models
ENERGY STAR Cold Climate	34.9%66 models	29.7%100 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

AUX
Lennox
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 25, 2026

Models per peer group · efficiency index within the group
Size and duct type	AUX	Lennox
Ducted, up to 1.5 tons	6 · index 60%	23 · index 59%
Ducted, 2 tons	4 · index 59%	48 · index 45%
Ducted, 2.5–3 tons	9 · index 63%	85 · index 45%
Ducted, 3.5–4.5 tons	5 · index 61%	101 · index 44%
Ducted, 5 tons and up	None	30 · index 47%
Non-ducted, up to 1.5 tons	120 · index 46%	47 · index 56%
Non-ducted, 2 tons	33 · index 52%	17 · index 58%
Non-ducted, 2.5–3 tons	22 · index 46%	20 · index 58%
Non-ducted, 3.5–4.5 tons	2 · index 73%	8 · index 47%
Non-ducted, 5 tons and up	None	4 · index 57%

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	AUXCold-climate score, best model	LennoxCold-climate score, best model
Ducted, up to 1.5 tons	75.4(50 is the typical model of its size class)ASUM18HPMULO6 of 6 models qualify · AHRI 216032437	87.1(50 is the typical model of its size class) (higher)A-VXP18SA-1with ducted air handler WXP18SA15 of 23 models qualify · AHRI 217482406
Ducted, 2 tons	62.9(50 is the typical model of its size class)ASUM24HPMULO4 of 4 models qualify · AHRI 216032438	88.7(50 is the typical model of its size class) (higher)SL22KLV-024-230A**with ducted air handler CBK48MVT-042-230-26 of 51 models qualify · AHRI 216379010
Ducted, 2.5–3 tons	73.8(50 is the typical model of its size class)ASPR30HPMULO6 of 9 models qualify · AHRI 216032400	93.7(50 is the typical model of its size class) (higher)SL22KLV-036-230A**with ducted air handler CBK48MVT-060-230-29 of 82 models qualify · AHRI 216776011
Ducted, 3.5–4.5 tons	77.1(50 is the typical model of its size class)ASUM42HPMULO5 of 5 models qualify · AHRI 216032440	90.6(50 is the typical model of its size class) (higher)SL22KLV-060-230A**with indoor coil D(A,C,E)60D3J+TDR and furnace SLP99UH110XV60C27 of 100 models qualify · AHRI 217443918
Ducted, 5 tons and up	No models in this size class	84.3(50 is the typical model of its size class)VPD060H6M-5P5 of 31 models qualify · AHRI 216054512
Non-ducted, up to 1.5 tons	83.5(50 is the typical model of its size class)AM2-H18/2DR3BAlso listed as ASUM18HPMULO80 of 120 models qualify · AHRI 214097940	97.0(50 is the typical model of its size class) (higher)A-VHP06SA-1with ductless indoor unit B-VHP06SA-131 of 47 models qualify · AHRI 216097104
Non-ducted, 2 tons	84.6(50 is the typical model of its size class)AM3-H24/2DR3BAlso listed as ASUM24HPMULO16 of 33 models qualify · AHRI 214097943	90.0(50 is the typical model of its size class) (higher)A-VHP24SA-1with ductless indoor unit B-VHP24CA-111 of 17 models qualify · AHRI 217482451
Non-ducted, 2.5–3 tons	73.4(50 is the typical model of its size class)AM4-H36/2DR3BAlso listed as ASUM36HPMULO18 of 22 models qualify · AHRI 214097941	82.7(50 is the typical model of its size class) (higher)VPD036S6M-5P15 of 20 models qualify · AHRI 216054505
Non-ducted, 3.5–4.5 tons	60.1(50 is the typical model of its size class)ASUM42HPMULO2 of 2 models qualify · AHRI 216050942	73.6(50 is the typical model of its size class) (higher)A-VHP486A-16 of 8 models qualify · AHRI 216097135
Non-ducted, 5 tons and up	No models in this size class	83.9(50 is the typical model of its size class)VPD060H6M-5P4 of 4 models qualify · AHRI 216054508

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	AUXAll-around score, best model	LennoxAll-around score, best model
Ducted, up to 1.5 tons	79.8(50 is the typical model of its size class)ASUM18HPMULO6 of 6 models have all five ratings · AHRI 216032437	86.9(50 is the typical model of its size class) (higher)A-VHP09SA-1with ducted air handler B-VHP09DA-122 of 23 models have all five ratings · AHRI 217482441
Ducted, 2 tons	78.2(50 is the typical model of its size class)ASUM24HPMULO4 of 4 models have all five ratings · AHRI 216032438	90.1(50 is the typical model of its size class) (higher)A-ZHP24SA-1with ducted air handler B-ZHP24SA-146 of 47 models have all five ratings · AHRI 218027842
Ducted, 2.5–3 tons	81.4(50 is the typical model of its size class)ASUM36HPMULO9 of 9 models have all five ratings · AHRI 216032439	95.1(50 is the typical model of its size class) (higher)SL22KLV-036-230A**with ducted air handler CBK48MVT-060-230-84 of 84 models have all five ratings · AHRI 216776011
Ducted, 3.5–4.5 tons	87.2(50 is the typical model of its size class) (higher)ASUM42HPMULO5 of 5 models have all five ratings · AHRI 216032440	86.5(50 is the typical model of its size class)SL22KLV-048-230Awith indoor coil CK40[C,U]T-60C-+TDR and furnace SL280UH080NV60C97 of 97 models have all five ratings · AHRI 216776088
Ducted, 5 tons and up	No models in this size class	84.7(50 is the typical model of its size class)VPD060H6M-5P36 of 36 models have all five ratings · AHRI 216054512
Non-ducted, up to 1.5 tons	84.2(50 is the typical model of its size class)ASW-H18E3B2/R3DI-D2with ductless indoor unit ASW-H18E3B2/R3DI-D2Also listed as ASW-H18E3B2/**R3DI-D2102 of 120 models have all five ratings · AHRI 215218928	96.5(50 is the typical model of its size class) (higher)A-VHP06SA-1with ductless indoor unit B-VHP06SA-140 of 47 models have all five ratings · AHRI 216097104
Non-ducted, 2 tons	87.0(50 is the typical model of its size class)ASW-H24F6A2/ R3DI-D7with ductless indoor unit ASW-H24F6A2/ R3DI-D7Also listed as ASW-H24F6A2/**R3DI-D729 of 33 models have all five ratings · AHRI 217115274	89.0(50 is the typical model of its size class) (higher)A-KZP24SA-1with ductless indoor unit B-KZP24SA-113 of 17 models have all five ratings · AHRI 218027843
Non-ducted, 2.5–3 tons	78.5(50 is the typical model of its size class)AM4-H36/2DR3BAlso listed as ASUM36HPMULO18 of 22 models have all five ratings · AHRI 214097941	79.1(50 is the typical model of its size class) (higher)VPD036S6M-5P16 of 20 models have all five ratings · AHRI 216054505
Non-ducted, 3.5–4.5 tons	74.4(50 is the typical model of its size class)ASUM42HPMULO2 of 2 models have all five ratings · AHRI 216050942	75.5(50 is the typical model of its size class) (higher)A-VHP486A-17 of 8 models have all five ratings · AHRI 216097133
Non-ducted, 5 tons and up	No models in this size class	91.5(50 is the typical model of its size class)VPD060H6M-5P4 of 4 models have all five ratings · AHRI 216054508

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	AUX	Lennox
COP at 5°F	beats 100% · 2.52AFEB09HP115V1CONon-ducted, up to 1.5 tons	beats 100% · 4.067HP14F30P-**ADucted, 2.5–3 tons
Capacity retention at 5°F	beats 99% · 108%AM3-H24/2DR3BAlso listed as ASUM24HPMULONon-ducted, 2 tons	beats 100% · 150%A-ZHP06SA-1Non-ducted, up to 1.5 tons
HSPF2	beats 96% · 11.0AM4-H36/2DR3BAlso listed as ASUM36HPMULONon-ducted, 2.5–3 tons	beats 100% · 15.6A-ZHP06SA-1Non-ducted, up to 1.5 tons
SEER2	beats 100% · 22.0ASUM42HPMULODucted, 3.5–4.5 tons	beats 100% · 27.0A-ZHP15SA-1Ducted, up to 1.5 tons
EER2	beats 97% · 14.0AMAR24HP230V1CONon-ducted, 2 tons	beats 100% · 15.0EL16KP1-018-230A**Also listed as ML14KP1-018-230ADucted, up to 1.5 tons
Heating capacity at 5°F	beats 99% · 21,800 Btu/hAM2-H18/2DR3BAlso listed as ASUM18HPMULONon-ducted, up to 1.5 tons	beats 100% · 54,000 Btu/hMMLD024S6S-1PNon-ducted, 2 tons

In the cold

NEEP cold-climate listings of both manufacturers against all listed models.

AUX vs Lennox: capacity and COP from 47°F downNEEP cold-climate listings at maximum capacity · 6,130 models (45.8% of the catalog) have ratings at 47, 17 and 5°F

All listed models (median, middle 50% and 80%)
AUX (median, middle 50%)
Lennox (median, middle 50%)

One curve per model: its NEEP-rated certification with the best 5°F COP. Every point of a curve is over the same models. NEEP lists only models submitted to it, so this is a cold-climate-leaning subset, not the whole catalog.

Show the data as a table

All listed models: capacity, % of its 47°F maximum
Scope, temperature	Models	10th pct.	25th	Median	75th	90th
All rated models, 47°F	6,130	100%	100%	100%	100%	100%
All rated models, 17°F	6,130	64%	69%	74%	83%	91%
All rated models, 5°F	6,130	57%	61%	69%	77%	83%

All listed models: COP at maximum capacity
Scope, temperature	Models	10th pct.	25th	Median	75th	90th
All rated models, 47°F	6,130	2.8	3.01	3.24	3.48	3.66
All rated models, 17°F	6,130	2	2.14	2.3	2.42	2.61
All rated models, 5°F	6,130	1.8	1.87	2	2.1	2.24

AUX: capacity, % of its 47°F maximum
Scope, temperature	Models	10th pct.	25th	Median	75th	90th
AUX, 47°F	65	100%	100%	100%	100%	100%
AUX, 17°F	65	67%	70%	73%	79%	85%
AUX, 5°F	65	62%	65%	70%	73%	83%

AUX: COP at maximum capacity
Scope, temperature	Models	10th pct.	25th	Median	75th	90th
AUX, 47°F	65	2.93	3.18	3.3	3.52	3.72
AUX, 17°F	65	2.1	2.17	2.28	2.34	2.45
AUX, 5°F	65	1.89	2	2	2.1	2.18

Lennox: capacity, % of its 47°F maximum
Scope, temperature	Models	10th pct.	25th	Median	75th	90th
Lennox, 47°F	136	100%	100%	100%	100%	100%
Lennox, 17°F	136	66%	69%	78%	85%	90%
Lennox, 5°F	136	56%	62%	71%	79%	84%

Lennox: COP at maximum capacity
Scope, temperature	Models	10th pct.	25th	Median	75th	90th
Lennox, 47°F	136	2.71	3.1	3.22	3.46	3.6
Lennox, 17°F	136	2.02	2.22	2.36	2.47	2.6
Lennox, 5°F	136	1.8	1.85	2	2.2	2.3

Source: NEEP ccASHP list · as of Oct 25, 2026

More comparisons

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AUX vs Lennox heat pumps