What is a Ton of Air Conditioning?
Air conditioning cooling capacity is measured in tons. The term is left over from the days when ice was an essential part of refrigeration and cooling systems – and tons (not just pounds) of ice were utilized for this purpose. One ton is equal to the amount of heat required to melt one ton (2,000 pounds) of ice in a 24-hour period. One ton of air conditioning is the amount of cooling required to freeze one ton of ice in a 24-hour period. The amount of energy required to freeze or melt a ton of ice is 288,000 Btu’s. Dividing 288,000 Btu’s by 24 hours is 12,000 Btu/hr.; therefore, one ton of air conditioning is equal to 12,000 Btu/hr. Typical residential air conditioning systems range from about 2 tons to 5 tons or from 24000 Btu/hr. to 60000 Btu/hr.
How Can You Find the Tonnage of Your Air Conditioner?
The tonnage of air conditioning systems is coded into the model number of the system. Go outside and look at your air conditioner’s condenser unit and find the data plate. Look at the model number and find a number that is divisible by 12 (12, 24, 36, 48, 60, etc.) When you have found that number, divide it by 12. The result of that is the tonnage of you air conditioner. For example, if you found a 36 in the model number, then you have a three-ton system. NOTE: Some systems are 2.5 tons, 3.5 tons, etc. In this case, you will not find a number divisible by 12. Instead you will find 18 (1.5 ton), 30 (2.5 ton), 42 (3.5 ton), etc. See the photos below for examples.