First, the measures that manufacturers can adopt in terms of fan coil units

1. Increase the fin spacing of fan coil heat exchanger and reduce the number of rows of tubes in heat exchanger, thus reducing the flow resistance on the air side of cooler. For example, choose two rows of tube fan coil instead of three or four rows of tube fan coil.

2. Choose the fan type and power range reasonably, and do not increase the noise value under large cold air volume, for example, choose low noise motor (such as DC brushless fan).

3. Increasing the diameter of the heat exchange tube can reduce the flow velocity and resistance of the fluid in the tube, such as increasing the cross-sectional area of the copper tube in the fan coil, selecting the appropriate large copper tube, controlling the water flow velocity in the tube and reducing the noise caused by the flow at the cooling coils bend or bifurcation

Second, the measures that can be adopted by the central air-conditioning engineer in terms of installation

1. select fan coil units with low noise. before selection, measure the noise between sample and prototype, and predict the difference between prototype and batch production, which is generally 5dB(A). In some large spaces, one large fan coil is replaced with two or more small fan coils to reduce noise while ensuring cooling capacity

2. The silencing material can be applied in the air supply duct and the air return duct, and the external insulation is changed into the internal insulation, and the perforated galvanized steel plate is added on the outer side of the insulation layer to make the silencing duct type

3. Increase the cross-section size of fan coil air supply duct and return duct, and reduce the airflow speed in the duct

4. Fan coil units in hotel rooms should be installed away from beds and desks: horizontal fan coil units are generally used to be installed on the ceiling in the lobby of the hotel rooms, and a pipe muffler with a length of 500-700mm is added in front of the air outlet, which can reduce the noise by about 6dB(A).

5. Replace the type of return air outlet, and adopt the air outlet with good airflow organization to ensure uniform and smooth air outlet

6. After the fan coil unit is installed, the air in the water system should be exhausted from the exhaust valves on the fan coil unit and pipeline to ensure that there is no bubble in the water pipe and reduce the indoor "running sound"

7. Water pipes, air pipes and fan coil units must be hoisted with elastic shock-absorbing hangers.

8. Flexible connections such as stainless steel hoses are used between water pipes and units. Canvas flexible connection is adopted between air duct and fan coil tuyere to achieve shock absorption and noise reduction