Compare tool

Compare models side by side

Pick two to four models. The best figure in each row is marked, and every number comes from the maker, NEEP or ENERGY STAR. Copy the URL to share a comparison.

All mini-splits & heat pumps ranked →All dehumidifiers ranked →All window, wall & room units ranked →All heating ranked →All parts, tools & supplies ranked →

SpecMrCool Olympus E Star 4th Gen 18,000 BTUGree Sapphire R32 18,000 BTU 230V
PhotoMrCool Olympus E Star 4th Gen 18,000 BTUGree Sapphire R32 18,000 BTU 230V
Our scoreSCORE7.4 / 10SCORE7.5 / 10
Our takeFull rated output at 5°F, the size we'd take for a cold-climate room or garage if a MrCool contractor quotes it fairly. Plan backup heat for -22°F nights, where it tops out at 8,000 BTU/h.18,000 BTU/h at 5°F against the Livo 18K's 12,100, for a cold-climate room with a licensed contractor.
Nominal size18,000 BTU18,000 BTU
Voltage230V230V
Rated heat at 47°F18,000 BTU/h18,600 BTU/h
Heat at 17°F18,000 BTU/h19,500 BTU/hbest
Heat at 5°F18,000 BTU/h18,000 BTU/h
Lowest heating temp-22°F-22°F
Max heat at lowest temp8,000 BTU/h10,800 BTU/hbest
SEER221.427.5best
HSPF2 (Region IV)11best10
Install typeFlareFlare
Max line run98.4 ft131 ftbest
Warranty covers owner installNoNo
Warranty, parts5 yr5 yr
Warranty, compressor7 yr7 yr
ENERGY STAR Cold ClimateYesn/a
ENERGY STARYesn/a
RefrigerantR-454BR-32
Watch out for"E Star" and the O-ES prefix also appear on an older R-410A Olympus (-230B condensers); confirm R-454B and an outdoor model ending -230C-O1. The Olympus listings on Amazon are the legacy R-410A Hyper Heat, not this unit. MrCool's FAQ says an HVAC professional must install it; the warranty's softer "may be necessary" wording doesn't change that.Amazon Sapphire titles show old SEER figures ("21.5 SEER" on the 24K); confirm the SAPxxHP230V1R32AH/AO model numbers. Gree's submittal prints lower 17°F figures than the certified NEEP ratings; go by NEEP. Gree's warranty applies only to installs by a state certified or licensed HVAC contractor, and claims are contractor-only.
More