Where can the evaporator used for central air conditioning be located?

The evaporator for central air conditioning systems can be located on either the return air side or the hot air side based on convenience, making this option the correct choice. This flexibility allows for various installation configurations depending on the layout of the building, space availability, and system design considerations.

When placed on the return air side, the evaporator can efficiently cool the air before it is sent into the conditioned space. Alternatively, if installed on the hot air side, it can effectively cool the air just before it's distributed throughout the space. This versatility is important for optimizing the air conditioning system's performance and ensuring adequate cooling based on specific circumstances.

Other options suggest limitations that don't reflect standard practices in HVAC design. For instance, stating that the evaporator can only be on the hot air side restricts installation possibilities, which is not typical in modern systems, where flexibility is key to effective cooling. Placing the evaporator exclusively in the return air on top of a blower cabinet or outside of the main airflow would also limit efficiency and practicality, as these scenarios would not allow for effective heat exchange or airflow management within the system. Thus, the correct answer reflects the adaptability needed in real-world applications of air conditioning systems.