Refrigeration Plant Operator B Practice Test

Is it true that the C.O.P. of a heat pump increases as the outside air temperature drops?

1. True

2. False

3. Depends on the refrigerant used

4. Only in specific conditions

The correct answer is: False

The statement that the Coefficient of Performance (C.O.P.) of a heat pump increases as the outside air temperature drops is false. The C.O.P. measures the efficiency of a heat pump; it is defined as the ratio of heating or cooling provided to the work required to operate the heat pump. As the outside air temperature drops, the heat pump has to work harder to extract heat from the colder air, which results in increased power consumption while providing less heat output. Consequently, the C.O.P. generally decreases at lower outside temperatures because the efficiency of heat transfer diminishes as the temperature gradient between the refrigerant and the outside air increases. This relationship between performance and outside temperature is particularly important in climates with cold winters, where heat pumps can struggle to maintain higher efficiencies. While factors like the type of refrigerant can influence performance to some extent and specific conditions can vary, the fundamental understanding is that lower temperatures typically lead to a decrease in C.O.P., making the original statement inaccurate.