Refrigeration Plant Operator B Practice Test

If an evaporator is rated at 120,000 BTU/hr, what must be true about the condenser?

1. It can be smaller than the evaporator

2. It must be larger than the evaporator

3. It should match the evaporator size

4. It must be equal to half the evaporator size

The correct answer is: It must be larger than the evaporator

For an evaporator rated at 120,000 BTU/hr, the condenser must be larger than the evaporator because the condenser is responsible for rejecting the heat extracted from the fluid in the evaporator, as well as any additional heat generated by the system. The evaporator absorbs heat from the refrigerated space, leading to a phase change in the refrigerant as it evaporates. This process requires the condenser to manage not only the heat absorbed from the evaporator but also any inefficiencies, heat from the compressor, and additional thermal loads. Therefore, the capacity of the condenser must exceed that of the evaporator to ensure it can effectively dissipate all the heat and maintain optimal system performance. If the condenser were smaller or equal in size to the evaporator, it would risk overheating and could lead to system inefficiencies or failures.