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.

EMI and Gridless 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, Gridless scores higher on 5 of the 6 ratings.

EMI
Gridless
Other ranked manufacturers

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

Average peer percentile, raw median and rank among ranked manufacturers
Rating	EMI	Gridless
Efficiency index	62%median —	70%median —
COP at 5°F	56%median 2.00	64%median 2.09
Capacity retention at 5°F	63%median 95%	73%median 88%
HSPF2	69% (higher)median 10.5	62% (higher)median 9.5
SEER2	61%median 21.4	73%median 22.0
EER2	60%median 12.5	73%median 12.3
Heating capacity at 5°F	60%median 18,000 Btu/h	66%median 18,000 Btu/h
Outdoor models	15	15
AHRI certifications	27	28

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
Standard	EMI	Gridless
CEE 2025 Tier 1 (Split ASHP)	86.7%13 models	100%15 models
CEE 2026 Tier 1 (Split ASHP)	86.7%13 models	100%15 models
CEE Advanced Tier (Split ASHP)	6.7%1 models	13.3%2 models
Xcel Energy Colorado cold-climate ASHP (2025)	73.3%11 models	100%15 models
DOE Cold Climate Heat Pump Challenge	6.7%1 models	13.3%2 models
ENERGY STAR Cold Climate	73.3%11 models	100%15 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 · 6 groups where both have models

EMI
Gridless
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	EMI	Gridless
Ducted, up to 1.5 tons	1 · index 77%	None
Ducted, 2.5–3 tons	2 · index 81%	1 · index 65%
Ducted, 3.5–4.5 tons	1 · index 84%	1 · index 82%
Ducted, 2 tons	None	1 · index 47%
Ducted, 5 tons and up	None	1 · index 81%
Non-ducted, up to 1.5 tons	8 · index 60%	7 · index 77%
Non-ducted, 2 tons	2 · index 53%	1 · index 61%
Non-ducted, 2.5–3 tons	4 · index 46%	2 · index 63%
Non-ducted, 3.5–4.5 tons	1 · index 76%	1 · index 44%

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	EMICold-climate score, best model	GridlessCold-climate score, best model
Ducted, up to 1.5 tons	70.8(50 is the typical model of its size class)EMXMZ218DA1 of 1 models qualify · AHRI 215444941	No models in this size class
Ducted, 2 tons	No models in this size class	82.1(50 is the typical model of its size class)GRID24OCwith ducted air handler GRID24VAH1 of 1 models qualify · AHRI 217115267
Ducted, 2.5–3 tons	82.5(50 is the typical model of its size class)EMXMZ436DA2 of 2 models qualify · AHRI 215444947	87.9(50 is the typical model of its size class) (higher)GRID36OCwith ducted air handler GRID36VAH1 of 1 models qualify · AHRI 217115268
Ducted, 3.5–4.5 tons	82.7(50 is the typical model of its size class) (higher)EMXMZ548DA1 of 1 models qualify · AHRI 215444950	77.3(50 is the typical model of its size class)GRID48OCwith ducted air handler GRID48VAH1 of 1 models qualify · AHRI 217115269
Ducted, 5 tons and up	No models in this size class	88.7(50 is the typical model of its size class)GRID60OCwith ducted air handler GRID60VAH1 of 1 models qualify · AHRI 217115270
Non-ducted, up to 1.5 tons	96.7(50 is the typical model of its size class) (higher)EMXSZ106DAwith ductless indoor unit EMXWAL06DA6 of 8 models qualify · AHRI 215444935	89.7(50 is the typical model of its size class)GRID09OHHVwith ductless indoor unit GRID09WHHV7 of 7 models qualify · AHRI 217101973
Non-ducted, 2 tons	88.4(50 is the typical model of its size class) (higher)EMXSZ124DAwith ductless indoor unit EMXWAL24DA2 of 2 models qualify · AHRI 215444939	54.1(50 is the typical model of its size class)GRID24OHVwith ductless indoor unit GRID24WHV1 of 1 models qualify · AHRI 217101978
Non-ducted, 2.5–3 tons	78.0(50 is the typical model of its size class) (higher)EMXMZ436DA2 of 4 models qualify · AHRI 215444948	53.7(50 is the typical model of its size class)GRID36OM42 of 2 models qualify · AHRI 217123264
Non-ducted, 3.5–4.5 tons	73.4(50 is the typical model of its size class) (higher)EMXMZ548DA1 of 1 models qualify · AHRI 215444951	16.4(50 is the typical model of its size class)GRID48OM51 of 1 models qualify · AHRI 217123265

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	EMIAll-around score, best model	GridlessAll-around score, best model
Ducted, up to 1.5 tons	77.4(50 is the typical model of its size class)EMXMZ218DA1 of 1 models have all five ratings · AHRI 215444941	No models in this size class
Ducted, 2 tons	No models in this size class	79.5(50 is the typical model of its size class)GRID24OCwith ducted air handler GRID24VAH1 of 1 models have all five ratings · AHRI 217115267
Ducted, 2.5–3 tons	83.6(50 is the typical model of its size class) (higher)EMXMZ436DA2 of 2 models have all five ratings · AHRI 215444947	82.3(50 is the typical model of its size class)GRID36OCwith ducted air handler GRID36VAH1 of 1 models have all five ratings · AHRI 217115268
Ducted, 3.5–4.5 tons	83.9(50 is the typical model of its size class) (higher)EMXMZ548DA1 of 1 models have all five ratings · AHRI 215444950	82.3(50 is the typical model of its size class)GRID48OCwith ducted air handler GRID48VAH1 of 1 models have all five ratings · AHRI 217115269
Ducted, 5 tons and up	No models in this size class	81.1(50 is the typical model of its size class)GRID60OCwith ducted air handler GRID60VAH1 of 1 models have all five ratings · AHRI 217115270
Non-ducted, up to 1.5 tons	96.2(50 is the typical model of its size class) (higher)EMXSZ106DAwith ductless indoor unit EMXWAL06DA8 of 8 models have all five ratings · AHRI 215444935	94.5(50 is the typical model of its size class)GRID09OHHVwith ductless indoor unit GRID09WHHV7 of 7 models have all five ratings · AHRI 217101973
Non-ducted, 2 tons	76.4(50 is the typical model of its size class) (higher)EMXSZ124DAwith ductless indoor unit EMXWAL24DA2 of 2 models have all five ratings · AHRI 215444939	61.3(50 is the typical model of its size class)GRID24OHVwith ductless indoor unit GRID24WHV1 of 1 models have all five ratings · AHRI 217101978
Non-ducted, 2.5–3 tons	78.3(50 is the typical model of its size class) (higher)EMXMZ436DA4 of 4 models have all five ratings · AHRI 215444946	64.2(50 is the typical model of its size class)GRID24OM32 of 2 models have all five ratings · AHRI 217123263
Non-ducted, 3.5–4.5 tons	75.6(50 is the typical model of its size class) (higher)EMXMZ548DA1 of 1 models have all five ratings · AHRI 215444949	43.7(50 is the typical model of its size class)GRID48OM51 of 1 models have all five ratings · AHRI 217123265

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	EMI	Gridless
COP at 5°F	beats 97% · 2.40EMXSZ106DANon-ducted, up to 1.5 tons	beats 98% · 2.42GRID60OCDucted, 5 tons and up
Capacity retention at 5°F	beats 94% · 110%EMXSZ106DANon-ducted, up to 1.5 tons	beats 94% · 75%GRID60OCDucted, 5 tons and up
HSPF2	beats 99% · 14.8EMXSZ106DANon-ducted, up to 1.5 tons	beats 96% · 10.5GRID36OCDucted, 2.5–3 tons
SEER2	beats 96% · 20.4EMXMZ548DADucted, 3.5–4.5 tons	beats 99% · 32.0GRID09OHHVNon-ducted, up to 1.5 tons
EER2	beats 99% · 18.0EMXSZ106DANon-ducted, up to 1.5 tons	beats 100% · 18.4GRID09OHHVNon-ducted, up to 1.5 tons
Heating capacity at 5°F	beats 97% · 19,000 Btu/hEMXMZ218DANon-ducted, up to 1.5 tons	beats 93% · 18,000 Btu/hGRID18OHVNon-ducted, up to 1.5 tons

More comparisons

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EMI vs Gridless heat pumps