What You Need to Know When Shopping for a Room Air Conditioner

Warm couple sitting on couch trying to fan themselves cool.

Don’t wait until it’s sweltering to think about buying a new room air conditioner—buy now and be ready when the first heatwave hits. Before you shop, consider these points to be sure you get the right air conditioner for your space.

Window Units Vs. Portable Units

video loop showing haier window air conditioner blowing into kitchen

Window Units

Window air conditioners sit in your window and the bulk of the unit hangs outside. They do take up window space and some people (including homeowner’s associations) don’t like the look of them from the exterior of the house. But they’re usually more efficient than a portable air conditioner and larger units with more BTUs can cool larger spaces. It may take more than one person to install a window AC unit—they can be heavy and must be installed level to be sure it drains well.


Haier portable air conditioner in room.

Portable Units

Portable AC units are very easy to install—most have a simple kit that fits in your open window where the vent hose exhausts warm air. Because the hose is fairly small, portable air conditioners take up less window space; however, the actual unit must sit inside the room and does take up floor space. Homes with casement windows (windows that open side to side instead of up and down) can’t accommodate window AC units but may accept portable units. If you need an AC boost in an upstairs room or office, a portable unit may work great. Plus, you can always move it to another room when needed.


Figuring Room Size and BTUs

Air conditioner cooling is rated in British Thermal Units, or BTUs. To see what size AC unit you need for your space, measure the room lengthwise and widthwise. Multiply the two measurements and you have your room’s square footage. If the space is open (not separated by a physical door) you may need to calculate two room sizes together to find the most efficient air conditioner to cool your total area. 


Next, divide the total square feet by 20—it takes about 20 BTUs to cool a square foot of home space. The result should tell you how many BTUs you’ll need the room air conditioner to be rated to keep your space cool. Most air conditioners supply BTU ratings in the thousands (e.g., a 6,000 BTU window air conditioner), so you will need to round up when shopping for a unit. 


Haier offers window AC and portable room air conditioners that produce between 5,000 and 23,500 BTUs, so you’re sure to find a unit to cool your space perfectly.