Question: What is the best portable air conditioner? This is somewhat of a tough question because there isn’t a single best portable air conditioner. Rather, there is the best portable air conditioner for your needs and requirements. To determine the best portable air conditioner for you, you should consider the following: How large is the room you are wanting to cool? Is the room upstairs or downstairs? What direction do the windows in the room face? Each of these questions will help decide how powerful your portable air conditioner should be to keep your room cool. Just because a room is small doesn’t mean the smallest portable air conditioner will be able to get the job done. If the room is upstairs, it will naturally be warmer than downstairs rooms because heat rises. Also, if the room has windows facing west, then it will get warmer in the afternoons because of the direct sunlight coming in. By keeping these things in mind, you are more likely to find the right portable air conditioner for you. We have this handy BTU calculator that will determine the total BTU needed for a portable air conditioner to cool your room. I’d recommend rounding the BTU up instead of down when making your buying decision — better safe than sorry. Once you know how powerful your portable air conditioner needs to be, look for units in that BTU range and read reviews to see what other shoppers have had to say (i.e. Is it quiet? Does it cool effectively? Is it cost efficient?). Look at reviews for the same portable air conditioner on different sites too if you can. This will help give you a well-rounded picture of how the unit will perform.