Before configuring the WiFi thermostat for the central air conditioner, the user needs to confirm the type of the fan coil unit used, and then select the corresponding WiFi thermostat. Generally, there are three types of fan coil units: two-pipe, three-pipe, and four-pipe. Here, EBEE Technology makes an introduction.
Two-pipe Fan Coil Unit
In the fresh air-fan-coil system or fan-coil system, the refrigerant and heating medium pipelines use the same pipeline system in winter and summer, that is, hot water and return water are used in winter, and the same pipeline is used to transport chilled water and the backwater, the switching of the cold and heat sources is carried out in the chilled water pump room and the heat exchange station, which is called a double pipe system. The double-pipe system can save investment costs and reduce maintenance. It is a control method commonly used in air conditioning systems, but it cannot meet the needs of annual air conditioning systems.
Three-pipe Fan Coil Unit
Two piping systems are installed for cold water and hot water, while the return water shares the same piping system.
Four-pipe Fan Coil Unit
Separate cold and hot water supply pipes and return pipe systems are used. The inlet and outlet pipes are equipped with switching control valves. They are mainly used for air conditioning systems throughout the year, that is, there are cold and heat sources at all times. And the amount of hot water and the cold water are adjusted through the temperature control valve and the control switching valve. Three-pipe and four-pipe systems are generally used in air-conditioning systems with special needs due to high investment and operating costs.
Zone Two-pipe Water System
When some air-conditioning areas in the building need to supply cold water throughout the year, and some air-conditioning areas are alternately supplied with cold and hot water, a zoned two-control water system should be adopted. This system has some characteristics of two-control and four-control, and its regulation performance is between four-control and two-control. Because from the adjustment range. The four-control system is the independent adjustment of each terminal device. The two-control system can only perform cold and heat conversion of the entire system together, while the zoned two-control system can realize independent control in different areas.
The key to the design of the zoned two-control system lies in the reasonable zone: if the zone is properly zoned, it can better meet the air requirements of different areas, and its regulation performance can be close to the four-control system. Regarding the number of partitions, the more partitions, the greater the number of areas that can be independently controlled, but the more complicated the piping system, not only the corresponding increase in investment but also the complexity of management, so the load change characteristics should be carefully analyzed during design Under normal circumstances, two areas can meet the needs. If in a building, the load difference caused by the inner, outer zone and orientation is obvious, it can also be divided into three zones. Compared with the current two-control system, the initial investment and building space occupied by the zoned two-control system are similar to those of the two-control system. When the zone is reasonable, the adjustment performance is similar to that of the four-control system. It is a way that can effectively improve the air conditioning standard and also A scheme that does not significantly increase investment, and its design combined with relevant new air conditioning technology can make the air conditioning system more economical and reasonable.
Based on the above difference, you can confirm the model of the central air conditioning WiFi thermostat you want to buy.