Refrigeration and Cop:

The standard unit of refrigeration is ton refrigeration or merely ton mentioned by TR. It is equal to the rate of heat transfer required to generate 1 ton (2000 lbs) of ice at 32 ⁰F from water at 32 ⁰F in one day that means, 24 hours. The enthalpy of solidification of water from & at 32 ⁰F in British thermal unit is 144 Btu/lb. Therefore

Generally, 1 TR refers 200 Btu of heat elimination per minute. Therefore if a refrigeration system is able of cooling at the rate of 400 Btu/min, this is a 2 ton machine. A machine of 20 ton rating is able of cooling at a rate of 20 * 200 = 4000 Btu/min. This unit of refrigeration is now in use, the UK, in the USA and India. In several countries, the standard MKS unit of kcal/hr is utilized. In the MKS it may be seen that

If Btu ton unit is expressed into SI system, this is found to be 210 kJ/min or 3.5 kW. Refrigeration influence is significant term in refrigeration that describes the amount of cooling formed by a system. This cooling is got at the cost of some form of energy. Thus, this is customary to define a term called coefficient of performance (COP) like the ratio of the refrigeration effect to energy input.

Whereas calculating COP, both refrigeration effect & energy input must be in the similar unit.