In North America, air conditioner equipment power is often described in tons of refrigerant. A ton of refrigerant is defined as the cooling power of one ton of ice melting in a 24 hour period. 1 ton is also equal to approximately 12,000 BTU. In the HVAC industry we throw around the term ton to describe the size of the air conditioner you need. In other words, the greater the number of tons of the unit, the larger the capacity of the unit which means the bigger the area it can cool. The larger the ton rating, however, the more energy the unit will use. This is why proper furnace and air conditioner sizing is so important.