Air conditioners are rated in Tons capacity instead of kW or kVA rating because Air conditioners are designed on the basis of the quantity of heat removal from a room, hall, or specific area.
Quantity of heat is termed in Tons means if an air conditioner is able to remove 1000 kilo calories of heat or 4120 kilo joules or 12000 BTU of heat in an hour that AC is rated as 1 Ton of AC because 1000 kilo calories or 4120 kilo joules or 12000 BTU equal to one Ton of heat.
The term “ton” refers to the amount of heat removed by an air conditioning unit that would melt a block of ice in a day.
One ton of cooling is equal to 12,000 BTUs (British Thermal Units) per hour.
A BTU is the amount of energy required to raise the temperature of one pound of water by one degree Fahrenheit at sea level.