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.

KARDA and SMARTFLEX 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, KARDA scores higher on 6 of the 6 ratings.

KARDA
SMARTFLEX
Other ranked manufacturers

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

Average peer percentile, raw median and rank among ranked manufacturers
Rating	KARDA	SMARTFLEX
Efficiency index	66% (higher)median —	29% (higher)median —
COP at 5°F	38% (higher)median 1.89	19% (higher)median 1.80
Capacity retention at 5°F	67% (higher)median 94%	65% (higher)median 74%
HSPF2	78% (higher)median 10.5	28% (higher)median 8.5
SEER2	78% (higher)median 21.1	21% (higher)median 17.5
EER2	63% (higher)median 12.0	19% (higher)median 10.2
Heating capacity at 5°F	64% (higher)median 17,700 Btu/h	59% (higher)median 21,800 Btu/h
Outdoor models	11	11
AHRI certifications	33	18

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
Standard	KARDA	SMARTFLEX
CEE 2025 Tier 1 (Split ASHP)	100%11 models	36.4%4 models
CEE 2026 Tier 1 (Split ASHP)	90.9%10 models	36.4%4 models
CEE Advanced Tier (Split ASHP)	0%0 models	0%0 models
Xcel Energy Colorado cold-climate ASHP (2025)	81.8%9 models	63.6%7 models
DOE Cold Climate Heat Pump Challenge	0%0 models	0%0 models
ENERGY STAR Cold Climate	72.7%8 models	0%0 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

KARDA
SMARTFLEX
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	KARDA	SMARTFLEX
Ducted, up to 1.5 tons	5 · index 61%	1 · index 22%
Ducted, 2 tons	2 · index 80%	1 · index 28%
Ducted, 2.5–3 tons	2 · index 64%	1 · index 24%
Ducted, 3.5–4.5 tons	1 · index 64%	1 · index 28%
Non-ducted, up to 1.5 tons	5 · index 71%	6 · index 22%
Non-ducted, 2 tons	1 · index 66%	1 · index 55%
Non-ducted, 2.5–3 tons	2 · index 60%	3 · index 41%
Non-ducted, 3.5–4.5 tons	1 · index 48%	1 · index 19%

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	KARDACold-climate score, best model	SMARTFLEXCold-climate score, best model
Ducted, up to 1.5 tons	74.9(50 is the typical model of its size class) (higher)3KARDA09SZOwith ducted air handler 3KARDA09UVD5 of 5 models qualify · AHRI 207796637	35.2(50 is the typical model of its size class)DHS18CMB22S1 of 1 models qualify · AHRI 207616613
Ducted, 2 tons	79.4(50 is the typical model of its size class) (higher)1KARDA24SZO20.5with ducted air handler 2PAMSDH24Also listed as 3KARDA24SZO2 of 2 models qualify · AHRI 206348123	45.7(50 is the typical model of its size class)DHS24CMB22S1 of 1 models qualify · AHRI 207616615
Ducted, 2.5–3 tons	57.4(50 is the typical model of its size class) (higher)3KARDA27MZ31 of 2 models qualify · AHRI 207657362	37.8(50 is the typical model of its size class)DHS36CMB22S1 of 1 models qualify · AHRI 207616618
Ducted, 3.5–4.5 tons	None on this board (0 of 1 models qualify)	40.5(50 is the typical model of its size class)DHS42CMB22S1 of 1 models qualify · AHRI 207616621
Non-ducted, up to 1.5 tons	77.0(50 is the typical model of its size class) (higher)3KARDA12SZOwith ductless indoor unit 3KARDA12CON-24 of 5 models qualify · AHRI 210410112	64.2(50 is the typical model of its size class)DHS18CMB22S5 of 6 models qualify · AHRI 207616612
Non-ducted, 2 tons	86.1(50 is the typical model of its size class) (higher)3KARDA24SZOwith ductless indoor unit 3KARDA24UVC1 of 1 models qualify · AHRI 207796643	66.1(50 is the typical model of its size class)DHS24CMB22S1 of 1 models qualify · AHRI 207616614
Non-ducted, 2.5–3 tons	49.3(50 is the typical model of its size class) (higher)3KARDA27MZ31 of 2 models qualify · AHRI 207657363	44.1(50 is the typical model of its size class)DHP36CSB22Swith ductless indoor unit DHP36NWB22S3 of 3 models qualify · AHRI 209818487
Non-ducted, 3.5–4.5 tons	None on this board (0 of 1 models qualify)	31.6(50 is the typical model of its size class)DHS42CMB22S1 of 1 models qualify · AHRI 207616620

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	KARDAAll-around score, best model	SMARTFLEXAll-around score, best model
Ducted, up to 1.5 tons	85.2(50 is the typical model of its size class) (higher)3KARDA09SZOwith ducted air handler 3KARDA09UVD5 of 5 models have all five ratings · AHRI 207796637	22.0(50 is the typical model of its size class)DHS18CMB22S1 of 1 models have all five ratings · AHRI 207616613
Ducted, 2 tons	80.1(50 is the typical model of its size class) (higher)1KARDA24SZO20.5with ducted air handler 2PAMSDH24Also listed as 3KARDA24SZO2 of 2 models have all five ratings · AHRI 206348123	27.7(50 is the typical model of its size class)DHS24CMB22S1 of 1 models have all five ratings · AHRI 207616615
Ducted, 2.5–3 tons	71.5(50 is the typical model of its size class) (higher)3KARDA27MZ32 of 2 models have all five ratings · AHRI 207657362	24.1(50 is the typical model of its size class)DHS36CMB22S1 of 1 models have all five ratings · AHRI 207616618
Ducted, 3.5–4.5 tons	63.5(50 is the typical model of its size class) (higher)3KARDA48MZ51 of 1 models have all five ratings · AHRI 207657369	28.0(50 is the typical model of its size class)DHS42CMB22S1 of 1 models have all five ratings · AHRI 207616621
Non-ducted, up to 1.5 tons	84.4(50 is the typical model of its size class) (higher)3KARDA09SZOwith ductless indoor unit 3KARDA09UVW5 of 5 models have all five ratings · AHRI 207430429	50.6(50 is the typical model of its size class)DHS18CMB22S6 of 6 models have all five ratings · AHRI 207616612
Non-ducted, 2 tons	70.7(50 is the typical model of its size class) (higher)3KARDA24SZOwith ductless indoor unit 3KARDA24UVW1 of 1 models have all five ratings · AHRI 207430431	55.4(50 is the typical model of its size class)DHS24CMB22S1 of 1 models have all five ratings · AHRI 207616614
Non-ducted, 2.5–3 tons	66.7(50 is the typical model of its size class) (higher)3KARDA27MZ32 of 2 models have all five ratings · AHRI 207657363	47.8(50 is the typical model of its size class)DHP36CSB22Swith ductless indoor unit DHP36NWB22S3 of 3 models have all five ratings · AHRI 209818487
Non-ducted, 3.5–4.5 tons	48.3(50 is the typical model of its size class) (higher)3KARDA48MZ51 of 1 models have all five ratings · AHRI 207657368	18.7(50 is the typical model of its size class)DHS42CMB22S1 of 1 models have all five ratings · AHRI 207616620

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	KARDA	SMARTFLEX
COP at 5°F	beats 65% · 2.003KARDA18MZ2Non-ducted, up to 1.5 tons	beats 53% · 1.85DHP36CSB22SNon-ducted, 2.5–3 tons
Capacity retention at 5°F	beats 93% · 108%3KARDA09SZODucted, up to 1.5 tons	beats 98% · 115%DHS24CMB22SNon-ducted, 2 tons
HSPF2	beats 98% · 12.03KARDA09SZODucted, up to 1.5 tons	beats 73% · 10.0DHS24CMB22SNon-ducted, 2 tons
SEER2	beats 98% · 21.03KARDA27MZ3Ducted, 2.5–3 tons	beats 51% · 20.0DHP30CSB22SNon-ducted, 2.5–3 tons
EER2	beats 95% · 15.83KARDA09SZONon-ducted, up to 1.5 tons	beats 53% · 11.3DHP30CSB22SNon-ducted, 2.5–3 tons
Heating capacity at 5°F	beats 93% · 27,000 Btu/h1KARDA24SZO20.5Also listed as 3KARDA24SZODucted, 2 tons	beats 99% · 21,800 Btu/hDHS18CMB22SNon-ducted, up to 1.5 tons

More comparisons

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KARDA vs SMARTFLEX heat pumps