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 4 of the 6 ratings.

EMI
Gridless
Other ranked manufacturers

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

Average peer percentile, raw median and rank among ranked manufacturers
Rating	EMI	Gridless
Efficiency index	58%median —	60%median —
COP at 5°F	49% (higher)median 1.90	40% (higher)median 1.84
Capacity retention at 5°F	67%median 82%	77%median 86%
HSPF2	68% (higher)median 9.6	60% (higher)median 9.5
SEER2	57%median 18.4	68%median 21.0
EER2	48%median 10.9	56%median 12.5
Heating capacity at 5°F	64%median 20,000 Btu/h	67%median 22,800 Btu/h
Outdoor models	22	11
AHRI certifications	41	11

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)	68.2%15 models	100%11 models
CEE 2026 Tier 1 (Split ASHP)	68.2%15 models	100%11 models
CEE Advanced Tier (Split ASHP)	0%0 models	0%0 models
Xcel Energy Colorado cold-climate ASHP (2025)	63.6%14 models	100%11 models
DOE Cold Climate Heat Pump Challenge	0%0 models	0%0 models
ENERGY STAR Cold Climate	72.7%16 models	90.9%10 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

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 11, 2026

Models per peer group · efficiency index within the group
Size and duct type	EMI	Gridless
Ducted, up to 1.5 tons	2 · index 55%	None
Ducted, 2 tons	1 · index 51%	1 · index 46%
Ducted, 2.5–3 tons	4 · index 63%	1 · index 63%
Ducted, 3.5–4.5 tons	3 · index 63%	1 · index 57%
Non-ducted, up to 1.5 tons	8 · index 56%	4 · index 63%
Non-ducted, 2 tons	2 · index 49%	2 · index 64%
Non-ducted, 2.5–3 tons	5 · index 57%	1 · index 70%
Non-ducted, 3.5–4.5 tons	1 · index 78%	1 · index 45%

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	63.7(50 is the typical model of its size class)MHSD118DACFCwith ducted air handler MHCO24DACFC2 of 2 models qualify · AHRI 218631472	No models in this size class
Ducted, 2 tons	66.5(50 is the typical model of its size class) (higher)MHSD124DACFCwith ducted air handler MHAH124DACFC1 of 1 models qualify · AHRI 216372808	57.5(50 is the typical model of its size class)O-AYC24SD-1with ducted air handler I-AYC24VAH-11 of 1 models qualify · AHRI 213249673
Ducted, 2.5–3 tons	78.6(50 is the typical model of its size class) (higher)MHSD136DACFCwith ducted air handler MHCO37DACFC4 of 4 models qualify · AHRI 218631475	75.1(50 is the typical model of its size class)O-AYC36SD-1with ducted air handler I-AYC36VAH-11 of 1 models qualify · AHRI 213249674
Ducted, 3.5–4.5 tons	74.9(50 is the typical model of its size class) (higher)MHMZ548DA3 of 3 models qualify · AHRI 208121942	56.6(50 is the typical model of its size class)O-AYC48SD-1with ducted air handler I-AYC48VAH-11 of 1 models qualify · AHRI 213249675
Non-ducted, up to 1.5 tons	89.3(50 is the typical model of its size class) (higher)MHSZ106DAwith ductless indoor unit MHWAL06DA6 of 8 models qualify · AHRI 208121923	72.9(50 is the typical model of its size class)O-AYD09SD-1with ductless indoor unit I-AYD09W-14 of 4 models qualify · AHRI 213265552
Non-ducted, 2 tons	86.1(50 is the typical model of its size class) (higher)MHSZ124DAwith ductless indoor unit MHCAS24DA1 of 2 models qualify · AHRI 208121931	56.8(50 is the typical model of its size class)O-AYD24SD-32 of 2 models qualify · AHRI 213255584
Non-ducted, 2.5–3 tons	79.3(50 is the typical model of its size class) (higher)MHMZ436DA2 of 5 models qualify · AHRI 208121938	64.0(50 is the typical model of its size class)O-AYD36SD-41 of 1 models qualify · AHRI 213255585
Non-ducted, 3.5–4.5 tons	76.2(50 is the typical model of its size class) (higher)MHMZ548DA1 of 1 models qualify · AHRI 208121941	41.8(50 is the typical model of its size class)O-AYD42SD-51 of 1 models qualify · AHRI 213255586

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	63.4(50 is the typical model of its size class)MHSD118DACFCwith ducted air handler MHAH118DACFC2 of 2 models have all five ratings · AHRI 216372807	No models in this size class
Ducted, 2 tons	65.8(50 is the typical model of its size class) (higher)MHSD124DACFCwith ducted air handler MHAH124DACFC1 of 1 models have all five ratings · AHRI 216372808	46.3(50 is the typical model of its size class)O-AYC24SD-1with ducted air handler I-AYC24VAH-11 of 1 models have all five ratings · AHRI 213249673
Ducted, 2.5–3 tons	74.6(50 is the typical model of its size class) (higher)MHMZ327DA4 of 4 models have all five ratings · AHRI 208121936	63.2(50 is the typical model of its size class)O-AYC36SD-1with ducted air handler I-AYC36VAH-11 of 1 models have all five ratings · AHRI 213249674
Ducted, 3.5–4.5 tons	82.0(50 is the typical model of its size class) (higher)MHMZ548DA3 of 3 models have all five ratings · AHRI 208121942	57.3(50 is the typical model of its size class)O-AYC48SD-1with ducted air handler I-AYC48VAH-11 of 1 models have all five ratings · AHRI 213249675
Non-ducted, up to 1.5 tons	92.0(50 is the typical model of its size class) (higher)MHSZ106DAwith ductless indoor unit MHWAL06DA8 of 8 models have all five ratings · AHRI 208121923	81.4(50 is the typical model of its size class)O-AYD09SD-1with ductless indoor unit I-AYD09W-14 of 4 models have all five ratings · AHRI 213265552
Non-ducted, 2 tons	84.3(50 is the typical model of its size class) (higher)MHSZ124DAwith ductless indoor unit MHWAL24DA2 of 2 models have all five ratings · AHRI 208121927	67.5(50 is the typical model of its size class)O-AYD24SD-32 of 2 models have all five ratings · AHRI 213255584
Non-ducted, 2.5–3 tons	82.8(50 is the typical model of its size class) (higher)MHMZ436DA4 of 5 models have all five ratings · AHRI 208121938	69.5(50 is the typical model of its size class)O-AYD36SD-41 of 1 models have all five ratings · AHRI 213255585
Non-ducted, 3.5–4.5 tons	77.9(50 is the typical model of its size class) (higher)MHMZ548DA1 of 1 models have all five ratings · AHRI 208121941	44.5(50 is the typical model of its size class)O-AYD42SD-51 of 1 models have all five ratings · AHRI 213255586

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 91% · 2.21MHSZ124DANon-ducted, 2 tons	beats 75% · 2.05O-AYC36SD-1Ducted, 2.5–3 tons
Capacity retention at 5°F	beats 92% · 107%MHSZ106DANon-ducted, up to 1.5 tons	beats 99% · 113%O-AYD36SD-4Non-ducted, 2.5–3 tons
HSPF2	beats 98% · 13.6MHSZ106DANon-ducted, up to 1.5 tons	beats 83% · 9.5O-AYC36SD-1Ducted, 2.5–3 tons
SEER2	beats 99% · 20.9MHMZ548DADucted, 3.5–4.5 tons	beats 89% · 25.5O-AYD09SD-1Non-ducted, up to 1.5 tons
EER2	beats 98% · 16.2MHSZ109DANon-ducted, up to 1.5 tons	beats 89% · 14.5O-AYD09SD-1Non-ducted, up to 1.5 tons
Heating capacity at 5°F	beats 96% · 20,000 Btu/hMHMZ218DANon-ducted, up to 1.5 tons	beats 92% · 18,000 Btu/hO-AYD18SD-2Non-ducted, up to 1.5 tons

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EMI vs Gridless heat pumps