Portable air conditionerUSA: Portable air conditioners are better than a fan, but not much, according to a new consumer report. 

US company Consumer Reports tested eight portable air conditioners and found that, despite their claims, they barely got a room below sweltering let alone the 78F (25.6C) that’s considered the upper threshold of indoor comfort in America.

The tests measured how long it takes a portable air conditioner to lower the temperature in a room appropriate for its claimed size from 90F (32C) to 75. According to Consumer Reports, few made it to even 80F (27C) after 100 minutes.

Consumer Reports claim to test portable air conditioners the same way they test window units and claim that most manufacturers don’t.

The US Department of Energy is said to be reviewing the current industry test for portable air conditioner capacity and efficiency. Consumer Reports further claims that the current test doesn’t account for what is often significant leakage and transfer of hot air into the space being cooled.