How Do You Size Room Air Conditioners?

Gwydion M. Williams/CC-BY 2.0

Use the area of a room to determine the proper air conditioner size estimate, which is measured in British thermal units per hour. A 100- to 150-square-foot room needs a 5,000 BTU per hour unit, while a 400- to 450-square-foot room needs a 10,000 BTU per hour unit.

ADVERTISEMENT