Match a room or small space to the capacity in the EPA room air conditioner chart, with the listed adjustments.
How it works
Finds capacity by floor area, then adjusts 10% for shade or strong sun, adds 600 BTU for each regular occupant past two, and adds 4,000 BTU for kitchens.
Before you order
- Oversizing cools quickly but removes less humidity.
- Ceilings above 8 feet need more capacity than the chart.
- Whole-house systems need a Manual J, since this chart is meant for single rooms.
Common questions
How many BTU per square foot is right?
Chart values fall around 20 to 30 BTU per square foot for small rooms, then taper for larger spaces. Use the chart, since one flat number misleads.
Does this work for central air?
Use it only for a rough check. Central systems should be sized with a Manual J load calculation by a licensed contractor.