What is the main function of a coil in an air handling unit?

• A. To provide heat transfer to air
• B. To remove moisture from the air
• C. To increase the pressure of the refrigerant
• D. To circulate the refrigerant through the system

Answer: (A)

The main function of a coil in an air handling unit is to provide heat transfer to the air. The coil serves as a heat exchanger, facilitating the transfer of thermal energy between the refrigerant or hot water inside the coil and the air passing over it. In cooling applications, the coil absorbs heat from the air, thus lowering the air temperature before it is circulated back into the space. Conversely, in heating applications, the coil adds heat to the incoming air, thereby increasing its temperature. This is crucial for maintaining comfortable indoor climate conditions.

In air handling units, coils can be designed for either heating or cooling, and their efficiency directly affects the overall performance of the HVAC system. This function is critical in ensuring that the desired temperature and comfort levels are achieved in the controlled environment.