The use effect of air conditioner is directly related to the quality of fan coil, so we should always check whether the fan coil works. However, sometimes because of the long-term use of air conditioners or the quality of air conditioners, there are problems in fan coils, so it is necessary to repair fan coils. However, many problems should be paid attention to when repairing fan coils. Today, let’s talk about what we should pay attention to.
Fan coil is an ideal end product of central air conditioning, which is composed of heat exchanger, water pipe, filter, fan, water tray, exhaust valve, bracket, etc. Its working principle is to continuously recirculate the air in the room where the unit is located, so that the air can be cooled (heated) after passing through 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 new fan coil unit(fcu), so as to meet the needs of the fresh air volume in the air-conditioned room. It is mainly composed of low noise motor, fins and heat exchange coils.
Fan coil unit(FCU)
1. Fan. Fan is one of the main components of fan coil air conditioner, which plays the role of conveying air. At the same time, it is the driving force that causes forced convection heat transfer in the coil and enhances the heat transfer capacity. At present, there are two types of fans used in fan coil units: multi-blade centrifugal fan and cross-flow fan.
2. Coil pipe. Coil is a heat exchanger, which is an important part of fan-coil unit. Nowadays, copper tubes are mostly used to string aluminum sheets, which are mechanically expanded to eliminate contact thermal resistance. There are also made of rolled sheet tubes, which are generally two-row tubes or three-row tubes.
3. Fan motor. Generally, capacitive circuit and oil bearing are adopted, and no oil is added at ordinary times. Note that if it is not an oil bearing, it should be oiled regularly. Usually, it has three gears to adjust the air volume, and the air volume adjustment range is about 50%.
4. Box body. The concealed box body is usually made of galvanized iron plate. Paint or plastic should be sprayed on the surface of the open-mounted box, and the iron plate should be treated by pickling and phosphating before spraying. There must be good heat preservation measures inside the box body, so that the unit can keep good heat preservation effect when running under wet conditions, so as to avoid condensation of the shell.
5. For high hydrostatic units. During assembly, there are serious air leakage problems at the joints of screw holes, plate joints, water receiving pans, copper tubes of surface cooler and side plates. When some units are under high static pressure, the air leakage rate is as high as 20%. It is suggested that manufacturers should pay attention to the sealing problems of units during assembly.