https://www.cnet.com/news/carriers-smart-air-conditioner-keeps-you-cool-at-ces-2018/

Carrier is back at CES, but this year it's all about air conditioners -- specifically its new 9,000 BTUh single zone ductless system. Yes, I know it's winter in many parts of the world right now, but this snazzy system is making some pretty big claims about its cooling capabilities. 

First up? Its energy rating. Carrier says its latest cooling appliance is the "most efficient" you can get in North America because of its "42 SEER" rating. A search on the U.S. Department of Energy site directed me to this piece of information: "Central air conditioners are rated according to their seasonal energy efficiency ratio (SEER). SEER indicates the relative amount of energy needed to provide a specific cooling output. Many older systems have SEER ratings of 6 or less."