How Do I Know What Portable A/C Unit Will Cover the Size of the Room I Need It In?

Measure the length and width of the room where you plan to use a portable air conditioner. Multiply these measurements together to calculate the square footage. For example, a room measuring 20 feet long by 15 feet wide is 300 square feet.

Match up your room size with the recommended BTUs for a portable air conditioner You can find guidelines online that help you do this. Most portable air conditioners also feature printed BTU guidelines on the packaging. For example, a room covering 300 square feet can typically be cooled with a portable AC rated at 10,000 BTUs.

Add 10 percent to the BTU rating for a sunny room that receives little to no shade during the day. Add 600 BTUs for every additional person beyond two people who regularly occupy the room. Add an extra 4,000 BTUs if you are using the portable unit to cool a kitchen.

Calculate a sunny kitchen of 300 square feet, for example, by adding the basic BTUs (10,000) plus 10 percent (1,000 BTUs) for a sunny room and another 4,000 BTUs (for a kitchen). This equals a recommended BTU rating of at least 15,000 BTUs. Bump up to 15,600 BTUs or higher if three or more people regularly occupy the kitchen.