Which of the following is a disadvantage of using a face damper for evaporator capacity control?

Using a face damper for evaporator capacity control can indeed reduce the air volume supplied to the space. This reduction occurs because the damper, when partially closed, restricts the airflow through the evaporator coil. While this may help control the cooling capacity, it can lead to inadequate air distribution and temperature imbalances within the conditioned space.

Additionally, limiting the air volume can result in less effective heat transfer within the evaporator, as there might not be sufficient airflow across the coil to absorb the heat efficiently. As a consequence, this can affect comfort levels and potentially lead to increased wear on the system as it operates under prolonged conditions of imbalance.

In contrast, the other choices mention aspects like increased energy consumption, complexity in refrigerant flow, and maintenance requirements. While these can be concerns in different contexts or with other control methods, they do not directly address the primary disadvantage linked to the face damper's immediate effect on air volume and distribution. Understanding these dynamics is crucial for proper HVAC system design and operation.