Room Size Consideration


BTUs (British Thermal Units) measure the amount of heat an air conditioner is able to remove over a given period. The higher the number, the greater the cooling capacity. However, bigger isn't always better. You have to match the BTU capacity of the air conditioner to the dimensions of the room in order to properly cool it. An underpowered air conditioner won't cool a large room properly. On the other hand, a unit with BTU rating that is too high cools the area so quickly it doesn't have time to dehumidify the air, which can leave the space feeling cold and clammy.

Always consider ceiling height, sizes of windows and doorways and whether the unit will be in a sunny room or a kitchen with extra heat from appliances, for example. All of these things are important when selecting the appropriate BTU rating to match a room by square feet.

Use the chart below to help you find the right BTU capacity for your space.


100 to 150 5,000
150 to 250 6,000
250 to 300 7,000
300 to 350 8,000
350 to 400 9,000
400 to 450 10,000
450 to 550 12,000
550 to 700 14,000
700 to 1,000 18,000
1,000 to 1,200 21,000
1,200 to 1,400 23,000
1,400 to 1,500 24,000
1,500 to 2,000 30,000
2,000 to 2,500 34,000