What do direct expansion systems utilize to cool the air stream for distribution?

Direct expansion systems rely on a cold evaporator coil to cool the air stream that is distributed throughout the space. In these systems, refrigerant circulates through the evaporator coil, where it absorbs heat from the air. As the refrigerant evaporates within the coil, it cools the air that passes over it, leading to a conditioned airflow entering the living or working space. This process is efficient and delivers fast cooling, which is essential in scenarios requiring rapid moisture evaporation and control, such as after water damage.

The other options describe components or systems that do not specifically function to cool the air stream in the same manner as a direct expansion system does. A warm condenser unit works in the opposite context by expelling heat, while a heat pump can both heat and cool but is not exclusive to direct expansion cooling methods. A chilled water tank represents a different type of cooling system that relies on a water-based approach, not the direct expansion technique. Thus, the cold evaporator coil is the key element utilized by direct expansion systems for air cooling.