What is the function of a fan coil unit in HVAC systems?

The function of a fan coil unit in HVAC systems is primarily to circulate air over water coils. This process allows the unit to either heat or cool the air before it is distributed into a space. The fan coil unit contains a fan that draws air from the room across the water-filled coils. Depending on the temperature of the water circulating through the coils, the air is either heated or cooled, which provides thermal comfort to the occupants of the space.

Using water for heat exchange is an efficient method compared to traditional air-based systems, as water can carry more heat than air, thus allowing for better energy transfer. This operation is central to maintaining desired temperature levels within a building, making the fan coil unit a crucial component in many HVAC systems.

Other functions related to HVAC, such as filtering air impurities, reducing noise, or removing outdoor air pollutants, do not directly describe the primary role of a fan coil unit. While some fan coil units may have basic filtering capabilities or may contribute indirectly to noise management, their main job is to manage the thermal environment by circulating air through water coils.