Ton of Refrigeration

 In the English system of units, there is a larger and more convenient measure of the rate of heat flow. It is called a ton of refrigeration. One ton of refrigeration produces the same cooling effect as the melting of 2000 lb of ice over a 24-hour period.

When 1 lb of ice melts, it absorbs 144 Btu. Therefore, when 1 ton (2000 lb) of ice melts, it absorbs 288,000 Btu (2000 x 144). Consequently, 1 ton of refrigeration absorbs 288,000 Btu within a 24-hour period or 12,000 Btu/hr (288,000/24). So, 1 ton of refrigeration is defined as the transfer of heat at the rate of 12,000 Btu/hr [3.517 kW].