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

In a refrigeration or air conditioning system, the relationship between the evaporator and condenser is crucial for efficient operation. An evaporator rated at 120,000 BTU/HR, which is equivalent to 10 tons of cooling capacity (since 1 ton equals 12,000 BTU/HR), suggests that it is capable of absorbing that amount of heat from the environment.

For the system to function properly, the condenser must be able to reject the heat absorbed by the evaporator. This means that it must be equipped to handle at least the same amount of heat that the evaporator delivers to it, which is 120,000 BTU/HR. However, in practice, it is advisable for the condenser to be larger than the evaporator. A larger condenser allows for more efficient heat rejection, prevents overheating, and ensures the system can operate effectively under varying load conditions.

Thus, the correct choice is that the condenser should be larger than the rated evaporator to accommodate the full capacity and allow for some margin of safety and efficiency, ensuring optimal performance of the system.