A fan coil unit is a common central air conditioning terminal device, primarily used to regulate indoor air temperature and humidity. It is one of the core components of an air conditioning system for achieving heat exchange. Its structure typically consists of a fan, coil (containing pipes for cold and hot media), casing, and control system. The fan forces air to flow across the surface of the coil, achieving heat exchange with the refrigerant (or heat transfer medium) inside the pipes, thereby regulating the indoor environment.
The core function of a fan coil unit relies on the efficiency of heat exchange between the coil and the air. The coil is generally made of copper or steel tubing, with aluminum foil fins wrapped around its surface to increase the heat exchange area and improve heat transfer efficiency. When the air conditioning system is running, chilled water (or hot water) circulates inside the coil. The fan draws in indoor air and blows it across the surface of the coil. The air temperature decreases (cooling mode) or increases (heating mode) due to heat exchange, and then the air is returned to the room through the outlet. Its control system can adjust the fan speed (e.g., high, medium, and low) and water flow to adapt to different needs.
