If you are shopping for or have just purchased a portable air conditioner, you may have noticed that the BTU’s on newer models appear to be significantly lower than older models. In some cases, portable air conditioners with the same model number may even show different BTUs depending on when they were manufactured. And it’s possible that the BTUs you see on the box may not match the BTUs you see on websites or other printed materials.
Despite the lower numbers, the cooling ability of portable air conditioners has not changed. The lower numbers are the result of a new test procedure that the Department of Energy now requires manufacturers to use to report cooling capacity of portable air conditioners. The new test procedure utilizes certain air temperature measurements not included in the previous test procedure. This is why the numbers appear lower. Different BTUs appearing on boxes and websites and for the same model numbers are simply a result of manufacturers making the transition to this new test procedure—the cooling capacities themselves have not changed.
Starting October 2017, manufacturers who decide to make cooling capacity claims must base those claims on the new test procedure. That test procedure includes a method for measuring cooling capacity, which DOE calls the seasonally adjusted cooling capacity.
What to look for when purchasing a portable air conditioner
The right air conditioner helps you cool a room efficiently. An undersized unit won't cool adequately while one that's too large will not remove enough humidity, leaving the air feeling damp. To find the proper air conditioner, determine the square footage of the room you want to cool by multiplying the room length by its width. Find the air conditioner's BTU rating, which indicates the amount of heat it can remove from a room. A higher number means more cooling power for a larger room. Be sure to “size up” if your portable air conditioner will be placed in a very sunny room, in a kitchen, or in a room with high ceilings. After you have found the right cooling capacity or your room, you can look at other features.