Fan coil units are widely used in hotels, office buildings, hospitals, commercial and residential buildings, and scientific research institutions. As the terminal equipment for cooling and heating, the cooling medium (cold water or hot water) and its own small fan rotate to make the surrounding air exchange heat with the cooling medium in the cooling and heating pipelines, blowing "cold air" or "hot air" indoors to achieve the purpose of cooling and heating indoors. So how does fan coil control the indoor temperature?  There are mainly the following points:

1. Control of wind speed of fan.  (The bigger the fan is turned on, the more obvious the temperature exchange is)

2. Control the valve at the inlet.  (The indoor temperature is controlled by controlling the valve in the refrigerant supply pipeline. For example, if the indoor temperature is too low in the cooling process, the valve in the refrigerant supply pipeline will be turned down, and the refrigerant circulation speed will be slow. In a very short time, the "cooling capacity" of the refrigerant will be consumed and the temperature will slowly rise.  )

3. Control of outlet valve.  (The principle is the same as that of the inlet valve, and the temperature is controlled to increase or decrease by controlling the flow rate of refrigerant circulation)

Fan coil units are generally connected by three pipelines. During the cooling and heating process of the ground source heat pump system, the cold water or hot water delivered by the ground source heat pump unit flows through the main conduit of the water heating well, then flows to the corridor branch conduit, and finally enters the indoor branch conduit. The main conduit of the supply and return water and the water heating are all encapsulated by rubber and plastic insulation cotton to avoid heat loss.  (Similarly, the ground source heat pump system can also supply cold and hot water to the fan coil by any centralized cold and hot source)

The temperature difference between the supply and return water directly leads to the change of the indoor cooling and heating efficiency. When the temperature difference between the supply and return water of some coil pipes is 2℃, the difference between the indoor cooling and heating energy is about 15%.  Let's talk about it here: fan coil unit is equivalent to indoor circulation of air. unlike fresh air heat exchanger unit, fresh air heat exchanger unit not only has cooling and heating effects, but also can exchange indoor and outdoor air. in the process of generating fresh air, it also provides cooling and heating.

The same as the common air conditioning system is that during the cooling process of the fan coil unit, condensate water is discharged. Therefore, when installing the fan coil unit in the construction project, besides connecting the supply and return pipe, the condensate water still needs to be connected, and the condensate water is discharged automatically. Therefore, during the installation process, the gradient needs to be adjusted to ensure the smooth discharge of condensate water. At the same time, when connecting with the fan coil unit, the condensate water pipe should be reserved with a "trap" to ensure that the condensate water will not flow back into the fan coil unit.