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.

NOVAIR and Viessmann 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, NOVAIR scores higher on 5 of the 6 ratings.

NOVAIR
Viessmann
Other ranked manufacturers

Source: AHRI Directory, NEEP · as of Oct 9, 2026

Average peer percentile, raw median and rank among ranked manufacturers
Rating	NOVAIR	Viessmann
Efficiency index	63% (higher)median —	53% (higher)median —
COP at 5°F	48%median 1.91	52%median 1.95
Capacity retention at 5°F	64% (higher)median 82%	50% (higher)median 67%
HSPF2	73% (higher)median 9.8	63% (higher)median 9.2
SEER2	69% (higher)median 21.5	58% (higher)median 18.7
EER2	60% (higher)median 12.5	46% (higher)median 10.7
Heating capacity at 5°F	67% (higher)median 20,000 Btu/h	50% (higher)median 18,000 Btu/h
Outdoor models	25	53
AHRI certifications	53	123

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
Standard	NOVAIR	Viessmann
CEE 2025 Tier 1 (Split ASHP)	88%22 models	64.2%34 models
CEE 2026 Tier 1 (Split ASHP)	84%21 models	60.4%32 models
CEE Advanced Tier (Split ASHP)	0%0 models	3.8%2 models
Xcel Energy Colorado cold-climate ASHP (2025)	80%20 models	43.4%23 models
DOE Cold Climate Heat Pump Challenge	0%0 models	3.8%2 models
ENERGY STAR Cold Climate	80%20 models	47.2%25 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 · 7 groups where both have models

NOVAIR
Viessmann
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 9, 2026

Models per peer group · efficiency index within the group
Size and duct type	NOVAIR	Viessmann
Ducted, up to 1.5 tons	4 · index 57%	6 · index 61%
Ducted, 2 tons	1 · index 51%	4 · index 65%
Ducted, 2.5–3 tons	7 · index 64%	9 · index 55%
Ducted, 3.5–4.5 tons	2 · index 53%	6 · index 59%
Ducted, 5 tons and up	None	2 · index 49%
Non-ducted, up to 1.5 tons	12 · index 62%	20 · index 53%
Non-ducted, 2 tons	2 · index 81%	4 · index 47%
Non-ducted, 2.5–3 tons	5 · index 68%	11 · index 47%
Non-ducted, 3.5–4.5 tons	None	5 · index 46%

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	NOVAIRCold-climate score, best model	ViessmannCold-climate score, best model
Ducted, up to 1.5 tons	63.7(50 is the typical model of its size class)LEA18-EVOX-30-Owith ducted air handler LEA-18/24-ACOIL-410A4 of 4 models qualify · AHRI 214867643	81.3(50 is the typical model of its size class) (higher)DLCSRBH18AAKwith ducted air handler DLFSDAH18XHK5 of 6 models qualify · AHRI 215569862
Ducted, 2 tons	66.5(50 is the typical model of its size class)LEA24-EVOX-30-Owith ducted air handler LEA24-EVOX-30-I1 of 1 models qualify · AHRI 211253513	79.4(50 is the typical model of its size class) (higher)DLCSRBH24AAKwith ducted air handler DLFSDAH24XAK4 of 4 models qualify · AHRI 215569794
Ducted, 2.5–3 tons	78.6(50 is the typical model of its size class)LEA36-EVOX-30-Owith ducted air handler LEA-30/36-ACOIL-410A6 of 7 models qualify · AHRI 214867644	78.6(50 is the typical model of its size class)DLCURAH36ABKwith ducted air handler DLFULAH36XCX + CI3 of 9 models qualify · AHRI 215569769
Ducted, 3.5–4.5 tons	73.8(50 is the typical model of its size class)LEA48-EVOX-30-Owith ducted air handler LEA48-EVOX-30-I2 of 2 models qualify · AHRI 211253514	74.9(50 is the typical model of its size class) (higher)DLCMHBH48EAK4 of 6 models qualify · AHRI 215569823
Ducted, 5 tons and up	No models in this size class	None on this board (0 of 2 models qualify)
Non-ducted, up to 1.5 tons	89.3(50 is the typical model of its size class)LEA09SZ25SK-Owith ductless indoor unit 2LEA06UUSK-I9 of 12 models qualify · AHRI 211709681	95.0(50 is the typical model of its size class) (higher)DLCPRBH18AAKwith ductless indoor unit DLFPHBH18XAK11 of 20 models qualify · AHRI 215569835
Non-ducted, 2 tons	84.5(50 is the typical model of its size class)LEA24SZ35SK-Owith ductless indoor unit 2LEA24UUSK-I2 of 2 models qualify · AHRI 211709685	86.1(50 is the typical model of its size class) (higher)DLCSRBH24AAKwith ductless indoor unit DLFSCBH24XAK2 of 4 models qualify · AHRI 215569833
Non-ducted, 2.5–3 tons	79.3(50 is the typical model of its size class) (higher)LEA36MZ-4P-35SK-O*4 of 5 models qualify · AHRI 212920682	73.4(50 is the typical model of its size class)DLCMHBH36DAK2 of 11 models qualify · AHRI 215569824
Non-ducted, 3.5–4.5 tons	No models in this size class	80.5(50 is the typical model of its size class)DLCMHBH48EAK3 of 5 models qualify · AHRI 215569822

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	NOVAIRAll-around score, best model	ViessmannAll-around score, best model
Ducted, up to 1.5 tons	63.4(50 is the typical model of its size class)LEA18-EVOX-30-Owith ducted air handler LEA18-EVOX-30-I4 of 4 models have all five ratings · AHRI 211253511	85.2(50 is the typical model of its size class) (higher)DLCSRBH09AAKwith ducted air handler DLFSDAH09XAK6 of 6 models have all five ratings · AHRI 215569786
Ducted, 2 tons	65.8(50 is the typical model of its size class)LEA24-EVOX-30-Owith ducted air handler LEA24-EVOX-30-I1 of 1 models have all five ratings · AHRI 211253513	80.1(50 is the typical model of its size class) (higher)DLCSRBH24AAKwith ducted air handler DLFSDAH24XAK4 of 4 models have all five ratings · AHRI 215569794
Ducted, 2.5–3 tons	74.6(50 is the typical model of its size class) (higher)LEA28MZ-3P-35SK-O7 of 7 models have all five ratings · AHRI 209416882	72.0(50 is the typical model of its size class)DLCMHBH30DAK9 of 9 models have all five ratings · AHRI 215569818
Ducted, 3.5–4.5 tons	53.3(50 is the typical model of its size class)LEA60-EVOX-30-Owith ducted air handler LEA60-EVOX-30-I2 of 2 models have all five ratings · AHRI 211253512	82.0(50 is the typical model of its size class) (higher)DLCMHBH48EAK6 of 6 models have all five ratings · AHRI 215569823
Ducted, 5 tons and up	No models in this size class	57.1(50 is the typical model of its size class)DLCLRCH58AAKwith ducted air handler DLFLDAH58XAK2 of 2 models have all five ratings · AHRI 215569836
Non-ducted, up to 1.5 tons	92.0(50 is the typical model of its size class)LEA09SZ25SK-Owith ductless indoor unit 2LEA06UUSK-I12 of 12 models have all five ratings · AHRI 211709681	93.6(50 is the typical model of its size class) (higher)DLCPRBH18AAKwith ductless indoor unit DLFPHBH18XAK20 of 20 models have all five ratings · AHRI 215569835
Non-ducted, 2 tons	84.3(50 is the typical model of its size class)LEA24SZ35SK-Owith ductless indoor unit 2LEA24UUSK-I2 of 2 models have all five ratings · AHRI 211709685	84.3(50 is the typical model of its size class)DLCSRBH24AAKwith ductless indoor unit DLFSHCH24XAK4 of 4 models have all five ratings · AHRI 215569840
Non-ducted, 2.5–3 tons	82.8(50 is the typical model of its size class) (higher)LEA36MZ-4P-35SK-O*5 of 5 models have all five ratings · AHRI 212920682	70.8(50 is the typical model of its size class)DLCMHBH36DAK11 of 11 models have all five ratings · AHRI 215569824
Non-ducted, 3.5–4.5 tons	No models in this size class	73.8(50 is the typical model of its size class)DLCMHBH48EAK5 of 5 models have all five ratings · AHRI 215569822

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	NOVAIR	Viessmann
COP at 5°F	beats 97% · 2.39LEA12SZ25SK-ONon-ducted, up to 1.5 tons	beats 99% · 2.89DLCPRBH18AAKNon-ducted, up to 1.5 tons
Capacity retention at 5°F	beats 92% · 107%LEA09SZ25SK-ONon-ducted, up to 1.5 tons	beats 97% · 120%DLCPRBH18AAKNon-ducted, up to 1.5 tons
HSPF2	beats 98% · 13.6LEA09SZ25SK-ONon-ducted, up to 1.5 tons	beats 100% · 15.0DLCPRBH09AAKNon-ducted, up to 1.5 tons
SEER2	beats 98% · 28.1LEA09SZ35SK-ONon-ducted, up to 1.5 tons	beats 99% · 20.9DLCMHBH48EAKDucted, 3.5–4.5 tons
EER2	beats 98% · 16.2LEA09SZ35SK-ONon-ducted, up to 1.5 tons	beats 98% · 16.2DLCSRBH09AAKNon-ducted, up to 1.5 tons
Heating capacity at 5°F	beats 96% · 20,000 Btu/hLEA20MZ-2P-35SK-ONon-ducted, up to 1.5 tons	beats 100% · 24,000 Btu/hDLCPRBH18AAKNon-ducted, up to 1.5 tons

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NOVAIR vs Viessmann heat pumps