Air conditioner equipment power in the U.S. is often described in terms of "
tons of refrigeration." A "ton of refrigeration" is defined as the cooling power of one
short ton (2000
pounds or 907
kilograms) of ice melting in a 24-
hour period. This is equal to 12,000
BTU per hour, or 3517
watts.
[13] Residential central air systems are usually from 1 to 5 tons (3 to 20
kilowatts (kW)) in capacity. To determine the correct size keep in mind that 12,000 BTU's equals 1-ton. Use the table below to determine the size AC that you need. Hope this helps.
Area To Be Cooled (square feet)
Capacity Needed (BTUs per hour)
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