ARCTIC KING vs Buck Cool heat pumps

Measured against models of the same size and duct type, Buck Cool scores higher on 6 of the 6 ratings. ARCTIC KING has 5 outdoor models, Buck Cool has 5 outdoor models. ARCTIC KING and Buck Cool have no QMID on file and are not ranked.

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CompareData as of Oct 11, 2026updated Oct 11, 2026 · sources

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.

ARCTIC KING and Buck Cool 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, Buck Cool scores higher on 6 of the 6 ratings.

ARCTIC KING
Buck Cool
Other ranked manufacturers

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

Average peer percentile, raw median and rank among ranked manufacturers
Rating	ARCTIC KING	Buck Cool
Efficiency index	35%median —	55%median —
COP at 5°F	40%median 1.85	60%median 1.98
Capacity retention at 5°F	28%median 64%	70%median 81%
HSPF2	29%median 9.0	33%median 8.6
SEER2	23%median 17.0	43%median 20.5
EER2	27%median 9.0	48%median 12.5
Heating capacity at 5°F	29%median 15,900 Btu/h	55%median 11,715 Btu/h
Outdoor models	5	5
AHRI certifications	5	5

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
Standard	ARCTIC KING	Buck Cool
CEE 2025 Tier 1 (Split ASHP)	20%1 models	80%4 models
CEE 2026 Tier 1 (Split ASHP)	20%1 models	80%4 models
CEE Advanced Tier (Split ASHP)	0%0 models	0%0 models
Xcel Energy Colorado cold-climate ASHP (2025)	0%0 models	80%4 models
DOE Cold Climate Heat Pump Challenge	0%0 models	0%0 models
ENERGY STAR Cold Climate	0%0 models	60%3 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 · 2 groups where both have models

ARCTIC KING
Buck Cool
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	ARCTIC KING	Buck Cool
Non-ducted, 2 tons	2 · index 35%	1 · index 59%
Non-ducted, 2.5–3 tons	1 · index —	1 · index —
Non-ducted, 3.5–4.5 tons	2 · index —	None
Non-ducted, up to 1.5 tons	None	3 · index 54%

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	ARCTIC KINGCold-climate score, best model	Buck CoolCold-climate score, best model
Non-ducted, up to 1.5 tons	No models in this size class	62.1(50 is the typical model of its size class)UB1MSHQCO09with ductless indoor unit UB1MSHQCW093 of 3 models qualify · AHRI 208287570
Non-ducted, 2 tons	None on this board (0 of 2 models qualify)	64.0(50 is the typical model of its size class)UB1MSHQCO24with ductless indoor unit UB1MSHQCW241 of 1 models qualify · AHRI 208287576
Non-ducted, 2.5–3 tons	None on this board (0 of 1 models qualify)	None on this board (0 of 1 models qualify)
Non-ducted, 3.5–4.5 tons	None on this board (0 of 2 models qualify)	No models in this size class

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	ARCTIC KINGAll-around score, best model	Buck CoolAll-around score, best model
Non-ducted, up to 1.5 tons	No models in this size class	56.5(50 is the typical model of its size class)UB1MSHQCO18with ductless indoor unit UB1MSHQCW183 of 3 models have all five ratings · AHRI 208287574
Non-ducted, 2 tons	56.4(50 is the typical model of its size class)MOD33-24HFN1-MT0Wwith ductless indoor unit MSAG11D-23HRFN1-MU0W2 of 2 models have all five ratings · AHRI 207821945	58.5(50 is the typical model of its size class) (higher)UB1MSHQCO24with ductless indoor unit UB1MSHQCW241 of 1 models have all five ratings · AHRI 208287576
Non-ducted, 2.5–3 tons	None on this board (0 of 1 models have all five ratings)	None on this board (0 of 1 models have all five ratings)
Non-ducted, 3.5–4.5 tons	None on this board (0 of 2 models have all five ratings)	No models in this size class

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	ARCTIC KING	Buck Cool
COP at 5°F	beats 55% · 1.90MOD33-24HFN1-MT0WNon-ducted, 2 tons	beats 81% · 2.13UB1MSHQCO24Non-ducted, 2 tons
Capacity retention at 5°F	beats 29% · 64%MOD33-24HFN1-MT0WNon-ducted, 2 tons	beats 69% · 89%UB1MSHQCO24Non-ducted, 2 tons
HSPF2	beats 57% · 9.3MOD30U-36HFN1-MNon-ducted, 2.5–3 tons	beats 57% · 9.5UB1MSHQCO12Non-ducted, up to 1.5 tons
SEER2	beats 66% · 21.0MOD33-24HFN1-MT0WNon-ducted, 2 tons	beats 67% · 22.5UB1MSHQCO18Non-ducted, up to 1.5 tons
EER2	beats 84% · 13.0MOD33-24HFN1-MT0WNon-ducted, 2 tons	beats 68% · 13.0UB1MSHQCO18Non-ducted, up to 1.5 tons
Heating capacity at 5°F	beats 35% · 16,700 Btu/hMOD33-24HFN1-MT0WNon-ducted, 2 tons	beats 83% · 13,770 Btu/hUB1MSHQCO18Non-ducted, up to 1.5 tons

More comparisons

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