Certified Energy Manager Practice Exam

How is the Coefficient of Performance (COP) calculated?

1. By dividing energy output by energy input

2. By calculating the ratio of heat delivered to work required

3. By averaging power over time

4. By measuring water consumption efficiency

The correct answer is: By calculating the ratio of heat delivered to work required

The Coefficient of Performance (COP) is a critical measure used in the evaluation of heating and cooling systems, representing the efficiency of these systems. It is specifically calculated as the ratio of heat output (the useful energy delivered for heating or cooling) to the work input (the energy consumed to operate the system). In heating applications, the COP provides insight into how effectively the system converts input energy into heat. For instance, a COP of 4 means that for every unit of energy consumed, the system delivers four units of heat. This makes the COP a valuable metric for comparing the efficiencies of different heating and cooling systems, as it allows for a straightforward assessment of their performance relative to their energy consumption. The other choices do not accurately represent the calculation of COP: dividing energy output by energy input generally applies to efficiency calculations but does not specify the heat-to-work ratio crucial for COP; averaging power over time refers more to energy use over a period rather than the performance ratio needed for COP; and measuring water consumption efficiency is unrelated to the concept of performance measurement in heating or cooling systems.