ARMSCO vs MAESTRO heat pumps

Measured against models of the same size and duct type, MAESTRO scores higher on 4 of the 6 ratings. ARMSCO has 7 outdoor models, MAESTRO has 7 outdoor models. ARMSCO and MAESTRO 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.

ARMSCO and MAESTRO 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, MAESTRO scores higher on 4 of the 6 ratings.

ARMSCO
MAESTRO
Other ranked manufacturers

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

Average peer percentile, raw median and rank among ranked manufacturers
Rating	ARMSCO	MAESTRO
Efficiency index	22%median —	31%median —
COP at 5°F	19% (higher)median 1.80	16% (higher)median 1.75
Capacity retention at 5°F	30% (higher)median 70%	28% (higher)median 66%
HSPF2	19%median 8.5	24%median 8.6
SEER2	27%median 19.0	34%median 21.0
EER2	16%median 10.0	44%median 13.0
Heating capacity at 5°F	32%median 8,600 Btu/h	59%median 10,750 Btu/h
Outdoor models	7	7
AHRI certifications	7	8

Share of models meeting each standard

Percent of each manufacturer’s models with a qualifying certification
Standard	ARMSCO	MAESTRO
CEE 2025 Tier 1 (Split ASHP)	71.4%5 models	57.1%4 models
CEE 2026 Tier 1 (Split ASHP)	57.1%4 models	57.1%4 models
CEE Advanced Tier (Split ASHP)	0%0 models	0%0 models
Xcel Energy Colorado cold-climate ASHP (2025)	57.1%4 models	42.9%3 models
DOE Cold Climate Heat Pump Challenge	0%0 models	0%0 models
ENERGY STAR Cold Climate	0%0 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 · 1 groups where both have models

ARMSCO
MAESTRO
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	ARMSCO	MAESTRO
Ducted, up to 1.5 tons	None	3 · index 4%
Non-ducted, up to 1.5 tons	5 · index 21%	4 · index 52%
Non-ducted, 2 tons	1 · index 25%	None
Non-ducted, 2.5–3 tons	1 · index 23%	None

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	ARMSCOCold-climate score, best model	MAESTROCold-climate score, best model
Ducted, up to 1.5 tons	No models in this size class	None on this board (0 of 3 models qualify)
Non-ducted, up to 1.5 tons	28.4(50 is the typical model of its size class)ACMS122419AAwith ductless indoor unit ACMS122419AAAlso listed as ACMS122420AB4 of 5 models qualify · AHRI 213829858	54.9(50 is the typical model of its size class) (higher)MA-12CA22SEXTwith ductless indoor unit MA-12CA22SINT3 of 4 models qualify · AHRI 205138202
Non-ducted, 2 tons	None on this board (0 of 1 models qualify)	No models in this size class
Non-ducted, 2.5–3 tons	None on this board (0 of 1 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	ARMSCOAll-around score, best model	MAESTROAll-around score, best model
Ducted, up to 1.5 tons	No models in this size class	4.5(50 is the typical model of its size class)22343 of 3 models have all five ratings · AHRI 214728344
Non-ducted, up to 1.5 tons	23.6(50 is the typical model of its size class)ACMS122419AAwith ductless indoor unit ACMS122419AAAlso listed as ACMS122420AB5 of 5 models have all five ratings · AHRI 213829858	56.8(50 is the typical model of its size class) (higher)MA-12CA22SEXTwith ductless indoor unit MA-12CA22SINT4 of 4 models have all five ratings · AHRI 205138202
Non-ducted, 2 tons	24.8(50 is the typical model of its size class)ACMS242420ABwith ductless indoor unit ACMS242420AB1 of 1 models have all five ratings · AHRI 213829862	No models in this size class
Non-ducted, 2.5–3 tons	23.4(50 is the typical model of its size class)ACMS362420ABwith ductless indoor unit ACMS362420AB1 of 1 models have all five ratings · AHRI 213829863	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	ARMSCO	MAESTRO
COP at 5°F	beats 26% · 1.80ACMS242420ABNon-ducted, 2 tons	beats 42% · 1.87MA-18CA22SEXTNon-ducted, up to 1.5 tons
Capacity retention at 5°F	beats 46% · 70%ACMS122419AAAlso listed as ACMS122420ABNon-ducted, up to 1.5 tons	beats 67% · 80%MA-12CA22SEXTNon-ducted, up to 1.5 tons
HSPF2	beats 25% · 8.5ACMS362420ABNon-ducted, 2.5–3 tons	beats 57% · 9.5MA-12CA22EXTNon-ducted, up to 1.5 tons
SEER2	beats 35% · 19.0ACMS362420ABNon-ducted, 2.5–3 tons	beats 67% · 22.5MA-18CA22SEXTNon-ducted, up to 1.5 tons
EER2	beats 25% · 10.0ACMS242420ABNon-ducted, 2 tons	beats 68% · 13.0MA-12CA22EXTNon-ducted, up to 1.5 tons
Heating capacity at 5°F	beats 61% · 11,600 Btu/hACMS182420ABNon-ducted, up to 1.5 tons	beats 83% · 13,770 Btu/hMA-18CA22SEXTNon-ducted, up to 1.5 tons

More comparisons

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