A ton is a unit of measurement for determining cooling capacity. One ton (or tonne) equals 12,000 Btuh. “Tonne” is typically used for cooling products manufactured outside the U.S.
Lennox® air conditioners and heat pumps are available in tonnages ranging from 1.5 to 5 ton capacities. Lennox package units are offered in tonnages spanning from 2 to 5 ton capacities.
An air-conditioning system or cooling system with a lower tonnage is typically smaller capacity units used in smaller homes, or are paired with another cooling unit to cool different parts of the same house. Under-sizing a unit means that it won’t be able to hold temperatures consistently on hot days. Higher-tonnage systems are oversized waste power and can create humidity problems in the home because the system won’t run long enough to remove much moisture from the air.