To cool a room of 400 square feet or more, you'll need an air conditioner with a capacity of at least 10,000 Btu. The best-rated unit we found in this size range is the Frigidaire FRA106CV1 (Est. $300) . In professional testing, this Energy Star-rated unit did an excellent job of maintaining the desired temperature and humidity, and it stood up very well to high temperatures and fluctuating power. However, testers noted that due to its weight, it was harder to install than other units its size.
The 60-plus Walmart reviews for the Frigidaire are highly positive, praising its cooling power, efficiency and ease of use. Users also appreciate the remote control with built-in thermostat, which can automatically adjust the settings from across the room. However, a few owners complained of the Frigidaire's noise level, especially on high speed.
The 10,000-Btu Kenmore 70101 (Est. $330) does almost as well in professional tests. Its ratings for performance, ease of use and noise level all matched the Frigidaire's, but it did a particularly poor job of directing airflow to the right. The Kenmore also doesn't do quite as well in the 60 user reviews we found at Sears.com (the only site that sells Kenmore appliances).
Owners praise the unit's cooling performance, value and ease of installation, but we found many complaints about its noise level, as well as a few about durability. Overall, only 80 percent of owners say they would recommend the Kenmore, as opposed to over 90 percent for the Frigidaire.
If you need an even more powerful unit, the Frigidaire FRA126CT1 (Est. $350) is the best-rated air conditioner we found in the 12,000-Btu range. TheSweetHome.com recommends this unit based on its useful features, such as the remote control, timer and air ionizer. Users at Walmart.com, Amazon.com and BestBuy.com also love these features, along with the unit's cooling performance and easy installation.
However, like other large air conditioners, it gets many complaints about its noise level. We also saw several gripes that the delicate cooling fins on this unit are easily damaged and prone to clogging, which can hamper the air conditioner's efficiency. However, some reviews note that most units this large have the same problem.