Portable air conditioners with a power rating of 10,000 Btu or less are suitable for smaller rooms -- up to 250 square feet in size. The best-rated portable unit in this size range is the 10,000-Btu NewAir AC-10000E (Est. $400) . Most reviewers say the NewAir AC-10000E does an excellent job of cooling small rooms. Some even claim that it can cool much larger spaces; one owner says it makes a 750-square-foot apartment "not just cool but cold." However, a few users disagree, saying the unit only managed to bump the temperature down by a few degrees.
One feature users especially like is this air conditioner's self-evaporative system, which is designed to remove moisture along with the exhaust air and reduce the need to drain the machine. Owners who live in dry climates say this feature eliminates the need for drainage completely. However, people in more humid areas say that they still need to empty the drainage pan, which can be a messy and awkward process.
The most common complaint we saw about the AC-10000E is that it's loud. Even reviewers who like the unit say that it's noisier than other air conditioners its size. We also saw several complaints that the lights on the air conditioner's display panel are too bright to use in a dark bedroom. Many owners say they were forced to cover the display with duct tape or fabric so that it wouldn't keep them awake.
A less expensive option is the Koldfront PAC801W ($310 ) . This 8,000-Btu unit is less powerful than the NewAir, so it can't cool a room much bigger than 200 square feet. The reviews we found for the Koldfront are a bit more mixed than those for the NewAir. While many owners praise its cooling power, we also saw quite a few complaints that it can't cool even a small room -- and it won't work at all in temperatures over 90 degrees.
Also, while the Koldfront has a self-evaporative system, it doesn't appear to work as well as the NewAir's. Many owners say they needed to empty the drainage tray frequently to keep it from overflowing. However, owners appreciate this unit's low price tag, and most say it is very easy to set up and use.