Legacy Systems heat pump efficiency: 11 outdoor models compared

Legacy Systems has 11 heat pump outdoor models certified with this refrigerant group, in 799 AHRI-certified combinations. Each model is compared with models of the same size and duct type, so the scores below do not depend on which sizes Legacy Systems makes. Legacy Systems has no QMID (IRS Qualified Manufacturer ID) on file, so it is not ranked against other manufacturers.

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ManufacturerData as of Oct 9, 2026updated Oct 10, 2026 · sources

Outdoor models: 11
AHRI certifications: 799
Efficiency index: 44%; Typical model vs same-size, same-type peers (11 models)
Meet CEE 2025: 0%; 0 models

How Legacy Systems compares with comparable models

For each rating: the share of same-size, same-type models that a typical model of this manufacturer beats (50% is typical), its rank, and the raw median for context. Raw medians are not comparable across manufacturers that make different sizes.

Legacy Systems against every ranked manufacturerPeer scores, 0–100 · grey ticks: each ranked manufacturer · shaded: the middle half of Legacy Systems’s own modelsLegacy Systems is strongest on EER2 (its typical model beats 87% of comparable models) and weakest on capacity retention at 5°F (17%).

Legacy Systems
Middle half of its models
Other ranked manufacturers

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

Average peer percentile of Legacy Systems’s models
Rating	Beats comparable models	Rank	Raw median
Efficiency index11 models scored	44%	Not ranked	—
COP at 5°F11 models scored	40%	Not ranked	1.90
Capacity retention at 5°F11 models scored	17%	Not ranked	50%
HSPF211 models scored	32%	Not ranked	7.8
SEER211 models scored	31%	Not ranked	15.0
EER211 models scored	87%	Not ranked	12.5
Heating capacity at 5°F11 models scored	23%	Not ranked	14,400 Btu/h

Standards met

Share of Legacy Systems’s models with at least one qualifying certification
Standard	Share	Models
CEE 2025 Tier 1 (Split ASHP)	0%	0
CEE 2026 Tier 1 (Split ASHP)	0%	0
CEE Advanced Tier (Split ASHP)	0%	0
Xcel Energy Colorado cold-climate ASHP (2025)	0%	0
DOE Cold Climate Heat Pump Challenge	0%	0
ENERGY STAR Cold Climate	0%	0

Sizes and duct types offered

Models per peer group, and how they score against the other models of that group.

Legacy Systems’s models inside each size and duct typeShape: every model of the group · blue: the middle half of this manufacturer’s models there, median dot, 10th–90th percentile line

Legacy Systems (median, middle 50%, 10th–90th)
All models of the group

Source: AHRI Directory · as of Oct 9, 2026

Share of comparable models beaten, per peer group
Size and duct type	Models	Index	COP@5°F	HSPF2	SEER2
Ducted, up to 1.5 tons	2	38%	37%	17%	34%
Ducted, 2 tons	2	35%	24%	26%	21%
Ducted, 2.5–3 tons	4	46%	45%	34%	28%
Ducted, 3.5–4.5 tons	3	52%	47%	46%	37%

Every Legacy Systems model in the market

Legacy Systems’s 11 models with a known size and duct type, over the shape of the whole catalog.

Legacy Systems models by size and ratingColoured: Legacy Systems · grey shapes: all 14,508 models · lines: catalog medians by size

Legacy Systems models
Ducted median by size
Non-ducted median by size
Every model at each size (width = count)
Standard threshold

Dots: 11 legacy systems models, each through its representative certification, in the colour of the rating shown. The grey shapes count all 14,508 models, half a ton at a time.

Show the data as a table

COP at 5°F by size and duct type (every model, by rated cooling capacity)
Duct type, size	Models	10th pct.	25th	Median	75th	90th
Ducted, 0.5 tons	826	1.64	1.71	1.75	1.85	2.24
Ducted, 1 ton	407	1.80	1.90	2.05	2.41	2.45
Ducted, 1.5 tons	992	1.75	1.86	2.00	2.17	2.40
Ducted, 2 tons	999	1.75	1.86	2.00	2.18	2.30
Ducted, 2.5 tons	1,040	1.70	1.80	2.00	2.10	2.36
Ducted, 3 tons	696	1.80	1.90	2.00	2.10	2.42
Ducted, 3.5 tons	864	1.70	1.80	2.00	2.10	2.46
Ducted, 4 tons	727	1.80	1.86	2.00	2.12	2.40
Ducted, 4.5 tons	690	1.70	1.80	1.90	2.10	2.20
Ducted, 5 tons	86	1.89	2.00	2.10	2.10	2.10
Non-ducted, 0.5 tons	1,186	1.75	1.80	1.90	2.00	2.22
Non-ducted, 1 ton	1,343	1.80	1.80	1.99	2.10	2.21
Non-ducted, 1.5 tons	1,261	1.80	1.80	2.00	2.10	2.31
Non-ducted, 2 tons	761	1.80	1.98	2.00	2.10	2.30
Non-ducted, 2.5 tons	403	1.80	1.85	2.00	2.00	2.10
Non-ducted, 3 tons	473	1.90	1.98	2.00	2.03	2.20
Non-ducted, 3.5 tons	280	2.00	2.00	2.00	2.05	2.10
Non-ducted, 4 tons	204	1.96	2.00	2.05	2.10	2.11
Non-ducted, 4.5 tons	78	1.90	1.91	1.95	2.01	2.01
Non-ducted, 5 tons	84	1.99	2.00	2.05	2.20	2.20

Source: AHRI Directory · as of Oct 9, 2026

Top Legacy Systems models

Its top five cold-climate picks and its top five all-around models across sizes (both scores compare each model with models of its own size and duct type, so sizes compare), then, on each single rating, the model that beats the largest share of comparable models.

Cold-climate picks

No Legacy Systems model keeps at least 70% of its heat at 5°F with all three cold-climate ratings.

All-around best

Top 5 Legacy Systems models on the all-around score across sizes. 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.
# · Outdoor model	Size · type	Cap. 5/47	COP@5°F	HSPF2	SEER2	EER2	Meets	Combos	AHRI ref.	Compared with	Score	Heating half	Cooling half	Cold-climate score
1GLZS4BA6010A*Legacy Systems · GLZS4Bwith ducted air handler AMST60DU1300A	4.5 tons56,500 Btu/h · Ducted	48%	2.00	8.2	14.5	12.5	None	1	215233838	Ducted, 3.5–4.5 tons	53.3	43.0	63.6	Not a pick
2GLZS4BA4810A*Legacy Systems · GLZS4Bwith ducted air handler AMST48CU1300A	4 tons45,500 Btu/h · Ducted	43%	2.00	7.8	15.2	12.5	None	1	215233836	Ducted, 3.5–4.5 tons	52.5	36.7	68.3	Not a pick
3GLZS4MA3010ALegacy Systems · GLZS4Mwith ducted air handler AWST30LU13*A	2.5 tons28,600 Btu/h · Ducted	53%	2.00	7.8	15.2	12.5	None	148	215234313	Ducted, 2.5–3 tons	52.0	40.4	63.5	Not a pick
4GLZS4BA4210A*Legacy Systems · GLZS4Bwith ducted air handler AMST42CU1300A	3.5 tons40,500 Btu/h · Ducted	51%	1.85	7.8	15.2	12.5	None	43	215233750	Ducted, 3.5–4.5 tons	50.3	32.4	68.3	Not a pick
5GLZS4BA3010ALegacy Systems · GLZS4Bwith ducted air handler CATA30263A+MBVB12BP1X00A	2.5 tons28,200 Btu/h · Ducted	52%	2.00	7.5	15.2	12.5	None	79	215233546	Ducted, 2.5–3 tons	50.1	36.6	63.5	Not a pick

Best model on each rating

Legacy Systems’s model with the highest peer percentile on each rating, ranked by that one rating only
Rating	Model	Value	Compared with	Beats	AHRI ref.
COP at 5°F	GLZS4BA3010A*	2.00	Ducted, 2.5–3 tons	56%	215233542
Capacity retention at 5°F	GLZS4MA3010A*	53%	Ducted, 2.5–3 tons	23%	215234313
HSPF2	GLZS4BA6010A*	8.2	Ducted, 3.5–4.5 tons	51%	215233838
SEER2	GLZS4BA4210A*	15.2	Ducted, 3.5–4.5 tons	35%	215233750
EER2	GLZS4BA4210A*	12.5	Ducted, 3.5–4.5 tons	93%	215233750
Heating capacity at 5°F	GLZS4BA1810A*	8,700 Btu/h	Ducted, up to 1.5 tons	46%	215233069

All 11 Legacy Systems models in Explore

Legacy Systems size class by size class: cold-climate and all-around

Its best model on each board in every size and duct type it makes. Both scores are 0–100 against every model of that size class (the line on each bar is 50, the typical model there). Cold-climate picks must keep at least 70% of their heat at 5°F; the all-around score needs all five ratings and has no such bar.

Legacy Systems: best cold-climate pick and best all-around model per size and duct type, with how many of its models are on each board (top 5 and 5 per class are in the snapshot)
Size and duct type	Cold-climate pickCold-climate score, best model	All-around bestAll-around score, best model
Ducted, up to 1.5 tons	None on this board (0 of 2 models qualify)	38.8(50 is the typical model of its size class)GLZS4MA1810A*with ducted air handler AMST24BU1300A2 of 2 models have all five ratings · AHRI 215233840
Ducted, 2 tons	None on this board (0 of 2 models qualify)	39.6(50 is the typical model of its size class)GLZS4MA2410A*with ducted air handler AMST24BU1300A2 of 2 models have all five ratings · AHRI 215233979
Ducted, 2.5–3 tons	None on this board (0 of 4 models qualify)	52.0(50 is the typical model of its size class)GLZS4MA3010Awith ducted air handler AWST30LU13*A4 of 4 models have all five ratings · AHRI 215234313
Ducted, 3.5–4.5 tons	None on this board (0 of 3 models qualify)	53.3(50 is the typical model of its size class)GLZS4BA6010A*with ducted air handler AMST60DU1300A3 of 3 models have all five ratings · AHRI 215233838

All-around board, every manufacturer

Newest Legacy Systems certifications

By AHRI reference number; AHRI issues references in increasing order.

The 5 most recently certified Legacy Systems outdoor models
Outdoor model	Size · type	COP@5°F	Cap. 5/47	HSPF2	SEER2	Meets	Combos	AHRI ref.
GLZS4MA3010ALegacy Systemswith ducted air handler 37HXS*X	2.5 tons28,600 Btu/h · Ducted	1.80	45%	7.5	14.3	None	148	217733356
GLZS4BA3010ALegacy Systemswith ducted air handler 36HXS*X	2.5 tons28,400 Btu/h · Ducted	1.80	46%	7.5	14.3	None	79	217732863
GLZS4MA2410ALegacy Systemswith ducted air handler 25CDX(E,Q,R,W)X+TXV	2 tons23,000 Btu/h · Ducted	1.72	44%	7.5	14.3	None	159	216980488
GLZS4BA2410ALegacy Systemswith ducted air handler 25CDX(E,Q,R,W)X+TXV	2 tons22,800 Btu/h · Ducted	1.82	43%	7.5	14.3	None	176	216980487
GLZS4MA3610ALegacy Systems · GLZS4Mwith indoor coil CATA3626*3A and furnace GR9T961005CNA	3 tons35,000 Btu/h · Ducted	1.90	51%	7.5	15.2	None	28	215234676

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Legacy Systems includes these brand names as listed in AHRI: Legacy Systems. Standards are checked against published thresholds; program rules beyond ratings are not checked.