What is a fan coil unit primarily used for in HVAC systems?

A fan coil unit is primarily utilized in HVAC systems for the purpose of circulating air over a coil that serves to either heat or cool the air. This component plays a critical role in temperature regulation within indoor environments by drawing in room air, passing it over the heating or cooling coil, and then distributing the conditioned air back into the space.

The coil is typically filled with either hot water or chilled water, allowing the fan coil unit to transfer thermal energy effectively. By adjusting the water supply to the coil, the system can respond dynamically to changes in the required indoor temperature, providing efficient thermal comfort.

The other options, while related to HVAC functions, do not accurately describe the primary role of a fan coil unit. Filtering air contaminants is generally the function of dedicated air filters or air handling units, controlling humidity levels is typically managed by dehumidifiers or dedicated systems, and regulating outdoor air intake pertains more to ventilation systems than to the fan coil unit’s specific design and operation.