Unit Sizing Guide

What Size Unit is Right for you?

Sources vary on how large a unit you should buy for a room of a given size, and experts say that factors such as multiple doors, sunny exposure and high ceilings will increase the Btu you need (air conditioner cooling is measure in British thermal units per hour). Consumer Reports magazine's estimates are on the low side compared to those offered by the United States Department of Energy. We've combined the two to give you a general air conditioner sizing guide. Calculate square footage by multiplying the length times the width of your room.

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Room Size Btu needed for a less sunny room Btu needed for a sunnier room
100 to 250 sq. ft. 5,000 to 6,000 5,500 to 6,600
250 to 350 sq. ft. 6,600 to 7,000 7,000 to 7,700
350 to 450 sq. ft. 7,700 to 9,000 9,000 to 10,000
450 to 550 sq. ft. 10,000 to 11,000 11,000 to 13,500
550 to 700 sq. ft. 12,000 to 13,500 13,500 to 15,000


*For more detailed info go to: www.energystar.gov