The COP (coefficient of performance) of a heat pump is always _______ the COP of a refrigerator.
The COP (coefficient of performance) of a heat pump is always Greater than the COP of a refrigerator.
Coefficient of Performance of a Refrigerator
In the case of refrigeration, the prime objective is cooling and this is possible only at the expense of some work. The performance index in the refrigeration cycle is, therefore, expressed (quantified) by a separate parameter called the coefficient of performance (abbreviated as COP).
COPr = Useful Refrigeration/Total work
In a household refrigerator, the freezer compartment where heat is absorbed by the refrigerant serves as the evaporator and the coils usually behind the refrigerator where heat is dissipated to the surroundings serve as the condenser.
COPrefrigerator = Q2/(Q1 − Q2)
Similarly, the objective of a heat pump is to pump in heat to a chamber for the purpose of heating and this is also possible only when some work is expended.
COPHeat pump = Heat delivered to Chamber/Total work
COPHeat pump = Q1/(Q1 − Q2)
From the expression of COP of refrigerator and heat pump., it is evident that the two are related by the following expressions.
COPHP = COPR + 1
From the above equation
The COP of a heat pump is greater than the COP of a refrigerator by unity.
The coefficient of performance of a heat pump is always greater than unity since COPR is a positive quantity.