Four-pipe fan coil

Shortcoming of four-pipe fan coil system is, ① large investment, operation and management of the pipeline due to the relatively complex ② more system design becomes more complex, larger pipeline space.

Four-pipe air conditioning means mounted air box while cold and heat pipe coils, each coil back into a total of four, so called four controls. Two water access were cold and hot water, that is, throughout the year no matter what time, cooling and heating can be switched at any time, you can achieve some of the rooms, while the heating, cooling and some rooms. So it's high standards, the cost is high. Two air-conditioning control box in just a coil, into a back pass summer cold water, hot water through the winter. Such a system makes the whole region can only heating or cooling at the same time. Compared with the four-pipe, a water system to save it, so it's relatively low standard, low cost.

 4-way cassette fan coil unit(4-pipe system)

Advantages of four-pipe system is that, ① each end device at any time freely choose the heating or cooling mode of operation, no mutual interference, air conditioning service region can independently control temperature and other parameters; ② save energy, all energy systems available by the end of the request, unlike the three control systems, as the presence of hot and cold against the problem. In a fresh air fan coil system or fan coil systems. Refrigerant and heat medium pipes in the winter and summer operation, all using the same piping system, namely winter and return hot water, the summer using the same piped chilled water ( and return), the heat source is switched in the freezing water pump and heat exchange stations, called two-pipe system. Two-pipe system can save investment costs, reduced maintenance, control the air conditioning system is a commonly used, but can not meet the needs of year-round air conditioning system.

Three controls are cold and hot water are provided two pipe system, and then return to share the same piping system.

Four-pipe is a separate hot and cold water supply pipe and a return pipe system, inlet and outlet pipe installation switching control valve, primarily for air conditioning systems used throughout the year, that at any time of cold and heat source used by the temperature control valve switch valve regulate cold, hot water. Three, four control systems due to the high investment and operating costs, usually with special needs air-conditioning systems in use.