ENERGY STAR cold-climate list

MAINLINE cold-climate mini-splits

The short answer

MAINLINE has 231 ENERGY STAR cold-climate certified system combinations. The median one is rated 18,000 BTU/h at 5°F, which is 90% of its 47°F capacity (the all-brand median is 88%), with a median HSPF2 of 10.5. Among the 80 brands with 50+ systems, it ranks #31 for keeping capacity in the cold.

231Certified systems

57Outdoor models

10.5Median HSPF2 (best 16.2)

2Median COP at 5°F

217ENERGY STAR Most Efficient listings

Capacity as it gets colder

Solid dots: 5°F and 47°F medians, joined by the straight line our model uses. Open dot: the 17°F median as reported, which is a separate test condition and often falls below the 5°F maximum-capacity figure.

Across the 231 systems, 5°F capacity runs from 6,500 to 54,000 BTU/h, so the model matters more than the badge. Refrigerants used: R-454B.

Highest-HSPF2 MAINLINE systems

Top 12 unique outdoor + indoor pairings by HSPF2
Outdoor model	Indoor model	HSPF2	BTU/h 47°F	BTU/h 17°F	BTU/h 5°F	COP 5°F	AHRI ref
ML18HP230CALH-O	ML18HP230CALH-I	16.2	20,000	19,300	22,600	2.34	215864347
ML18HP230CALH-O	ML18HP230CALH-I*	16.2	20,000	19,300	22,600	2.34	217607260
ML06HP230CALH-O	ML06HP230CALH-I	15.6	9,000	11,000	13,500	2	215864344
ML06HP230CALH-O	ML06HP230CALH-I*	15.6	9,000	11,000	13,500	2	217607257
ML09HP230CALH-O	ML09HP230CALH-I	14.6	12,000	11,000	13,500	2	215864345
ML09HP230CALH-O	ML09HP230CALH-I*	14.6	12,000	11,000	13,500	2	217607258
ML06HP230NEXH-O	ML06HP230NEX-I	14.6	7,000	8,000	7,500	2.3	215864338
ML06HP230NEXH-O	ML06HP230NEX-I*	14.6	7,000	8,000	7,500	2.3	217607251
ML09HP230NEX-O	ML09HP230CON-I	13.9	9,000	9,000	8,600	2.27	215864361
ML09HP230NEX-O	ML09HP230CON-I*	13.9	9,000	9,000	8,600	2.27	217607274
ML09HP230NEXH-O	ML09HP230HSDUC-I	13.8	9,900	10,200	11,900	1.85	215864377
ML09HP230NEXH-O	ML09HP230HSDUC-I*	13.8	9,900	10,200	11,900	1.85	217607290

Check the AHRI reference at ahridirectory.org before buying. We do not list prices: none of our sources publishes them.

Keep going

Put your ZIP into the cost-to-heat calculator to see what a median cold-climate system would cost to run where you live.
Sizing: how many BTU/h you need at your design temperature, compared with the 5°F capacity above.
Incentives and rebates and DIY vs installed for the buying decision.
Compare with similar brands: BLUERIDGE, Carrier, Midea, Bryant.

Questions people ask

How many MAINLINE mini-splits are ENERGY STAR cold-climate certified?

MAINLINE has 231 certified cold-climate system combinations across 57 outdoor models in the EPA's ENERGY STAR mini-split list, first certified 2025-07-24 and most recently 2026-08-11.

How well do MAINLINE units heat at 5°F?

The median MAINLINE system is rated 18,000 BTU/h at 5°F against 20,000 BTU/h at 47°F, or 90% (the all-brand median is 88%). Median COP at 5°F is 2.