Fan coil unit can be divided into water and gas. The cooling (heating) medium water is supplied by the central air conditioning cold (heat) source equipment (such as refrigerator), and is transported to the coil pipe for circulating flow under the action of water pump. The air path is that the air is inhaled into the room by the fan through the return air outlet, and then the air passes through the coil and exchanges heat with the cold (hot) medium water in the coil, and then it is cooled and dehumidified, and then sent into the room by the air supply outlet. In this way, the indoor temperature and humidity can be adjusted. Fan: driven by unidirectional multi speed low noise induction system motor, the fan speed is changed by adjusting the input voltage, so that the fan air volume is divided into three grades: high, medium and low, which is controlled by the electrical switch to adjust the cooling (heating) capacity of the fan coil. The fan is not only the power source of conveying air, but also the disturbance source of enhancing the convective heat transfer on the air side (the outer surface of coil), and the main noise source of the unit together with the motor. Coil: it is a kind of air-water heat exchanger with fin tube. The refrigerant water (hot water) flows in the pipe. Because the temperature of the refrigerant water is lower than the dew point temperature of the air, there is condensate on the outer surface of the pipe, which shows heat exchange under wet working condition, both heat exchange and mass exchange, which improves the heat exchange effect. The coil bears most or all of the air conditioning load in the room, and the pipe bank is generally 3-4 rows. Condensate pan: it is placed under the coil with the drain pipe, which is used to receive the water drops continuously condensed on the coil and discharge it out of the room by the drain pipe. Air filter: it is placed under the coil pipe with the drain pipe, and its function is to receive the water drops continuously condensed on the coil, and then discharge it out of the room by the drain pipe.
