
Find the Correct Portable Air Conditioner for Your Room Size
- Number of windows
- Level of insulation
- Presence of heat-producing appliances
- Ceiling height
- Number of people occupying the space
Why is the BTU rating so important? Buying a portable air conditioner that’s ill-suited for your space can harm both the PAC and your energy bill. If the unit has a BTU rating that’s too high, the unit will cool the room very quickly but repeatedly cycle off and on to maintain the desired temperature, raising your energy bill. This will also prevent the unit from adequately removing humidity from the air, leading to an unpleasantly muggy room. Alternatively, using a unit that has a BTU rating that’s too low for the space will force the unit to exert extra energy trying to cool down the room. Again, you’re left with a higher energy bill—this time, in a room that’s still too hot for comfort. How can I figure out the correct PAC for my room size?
The above graphic provides estimates of appropriate BTU ratings according to room square footage:
- 250-350 sq. ft. 8,000 BTU (ASHRAE)
- 350-450 sq. ft. 10,000 BTU (ASHRAE)
- 400-550 sq. ft. 12,000 BTU (ASHRAE)
- 550-700 sq. ft. 14,000 BTU (ASHRAE)