When the fan coil unit is in use, the cold and hot water is circulating all the time. If the electric two-way valve is not installed, the cold and hot water in the machine is still circulating when the power supply of the fan coil motor is turned off and the energy is still consumed, which does not conform to the principle of energy saving. The fan coil electric two-way valve is commonly known as solenoid valve. Its working principle is to use the magnetic field generated by the solenoid coil to pull to change the valve to change the valve, so, the valve core relies on the pressure of the spring to return.
Fan coil electric valves are generally divided into two types: normally closed and normally open. Normally closed type means that the valve is closed when power is off. Normally open type means that the valve is open when power is off. In addition, the wiring is divided into three-wire and two-wire systems. Most large-diameter electric valves are three-wire systems, while small-diameter electric valves are two-wire and three-wire systems.
Fan coil is the ideal end product of central air conditioning. It is composed of heat exchanger, water pipe, filter, fan, water receiving tray, exhaust valve, bracket, etc. The fan coil mainly relies on the forced action of the fan to make the air pass through the heater. When the surface is heated, the fan coil strengthens the convective heat exchange between the radiator and the air, and can quickly heat the air in the room. The fan coil is the end device of the air conditioning system, its working principle is that the air in the room is continuously recirculated in the unit, so that the air is cooled (heated) after passing through the cold water (hot water) coil to keep the room temperature constant. Usually, the fresh air is sent into the room after being treated by the fresh air unit to meet the needs of the fresh air volume in the air-conditioned room. Because this heating method is only based on convection heat exchange, the room cannot reach the optimal comfort level, therefore, it is only applicable to places where people stay for a short time, such as offices and hotels, hospitals, restaurants, factories, hospitals, exhibition halls, shopping malls and office buildings and other multi-room or large space industrial and civil buildings, due to the increase of fans, improve the cost and operating costs, equipment maintenance and management is also more complex.
In order to meet the design selection of different occasions, the types of fan coil can be customarily divided into horizontal concealed fan coil (with return air box), horizontal concealed fan coil, vertical concealed fan coil, vertical concealed fan coil, vertical exposed fan coil, card-type two-outlet fan coil, card-type four-outlet fan coil, cabinet-type fan coil, wall-mounted fan coil, etc.

According to the national standard "fan coil unit" part 4 classification, fan coil can be classified as follows:
The structure type is divided into horizontal type, vertical type (including column type and low type), card type, wall type and floor type.
According to the installation type, it is divided into open installation and concealed installation.
The water inlet direction is divided into left type (facing the air outlet of the unit, the water supply and return pipes are on the left side) and right type (facing the air outlet of the unit, the water supply and return pipes are on the right side).
During installation, attention should be paid to the insulation quality of the unit and the water supply and return pipes to prevent the generation of condensed water. The condensed water tray of the unit should drain smoothly, and the drainage of the unit should flow to the designated position with a slope of 3%.
Hose should be used for the connection between water pipe and fan coil, and the connecting pipe should be straight and no leakage is allowed.
The fan coil unit shall be connected with the water supply pipe after cleaning and discharging, and a filter shall be set on the water supply fan coil pipe leading to the unit to prevent the pipe from blocking the heat exchanger.
Use and maintenance of central air conditioning fan coil units.
Exhaust device shall be provided on the fan coil.
It is necessary to regularly remove the accumulated glow on the coil so that it has a good heat transfer effect.
In use, attention should be paid to excluding the air accumulated in the coil to ensure the heat exchange of air and avoid vibration and noise during work.
Regularly check whether the insulation material is damaged to prevent large heat leakage and condensed water.
Add lubricating oil to the fan motor every six months to make it have good running performance.
Water quality to meet the standard requirements, if the coil wall scale, should be removed.
The chilled water in use should not be lower than 5 ℃ to prevent condensation, and the hot water should not be higher than 80 ℃.
During the shutdown of the unit, the coil is filled with water to reduce corrosion to the inner wall of the pipe.
Drainage pipes shall not be flattened or bent to ensure smooth drainage.
Use should pay attention to the power supply, voltage, the fluctuation value should be within ± 10% of the rated voltage.
Shandong Xingheng Environmental Technology Group Co., Ltd. is located in Luquantun Development Zone, Dezhou, Shandong Province, the hometown of glass fiber reinforced plastic in China. The company has three-level qualification for construction mechanical and electrical installation engineering, three-level qualification for environmental protection engineering, and safety production license. It is the first in the industry to pass ISO9001 quality management system certification, ISO14001 environmental management system certification, OHSAS18001 occupational health management system certification, an axial fan invention patent, a fan utility model patent, EIA, three at the same time waiting for complete procedures