Causes and solutions of central air conditioner's air volume and noise failure

Causes and solutions of central air conditioner's air volume and noise failure

1. The dew point temperature of the machine is normal or low, and the reason and solution for slow indoor cooling.

　　① The air supply volume is less than the design value and the number of air changes is small. Please check whether the fan model meets the design requirements, whether the impeller steering is correct, whether the belt is loose, and open the large air supply valve to eliminate the insufficient air volume.

　　② For systems with secondary return air, the secondary return air volume is too large, please adjust to reduce the secondary return air volume.

　　③ There are many rooms in the air conditioning system, and the air volume is unevenly distributed. Please adjust to make the air volume evenly distributed in each room.

　　2. Reasons and solutions for the measured air volume of the system greater than the designed air volume.

　　① The actual resistance of the system is less than the design resistance, and the air volume of the fan increases. If conditions permit, the number of rotations of the fan can be changed.

　　② When designing, the fan capacity is too large, please close the small air volume control valve to reduce the air volume

　　3. Reasons and solutions for the overall measured air volume being less than the design air volume

　　① The actual resistance of the system is greater than the design resistance, and the air volume of the fan is reduced. When conditions permit, improve the duct components to reduce the system resistance.

　　② The system is blocked, please check and clear the possible blockages in the system.

　　③ If the system is leaking, it should be plugged.

　　④ If the fan fails to reach the design capacity or the impeller rotates in the wrong direction, the belt slips, etc., check and eliminate the factors that affect the fan output.

　　4. Reasons and solutions for indoor noise greater than design requirements.

　　① If the fan noise is higher than the rated value, please measure the fan noise, check whether the fan impeller hits the shell, whether the bearing is damaged, whether the shock absorption is good, and treat it symptomatically.

　　② The wind speed of the air pipe, valve and tuyere is too high, causing airflow noise. Please adjust various valves and tuyere to reduce the excessive wind speed.

　　③ The noise reduction equipment of the air duct system is not perfect, please add noise reduction elbows and other equipment.

　　 5. The total air supply volume of the system does not match the total air intake volume, and the large difference is the cause and solution.

　　① The air volume measurement method and calculation are incorrect. Please review the measurement and calculation data.

　　② If the system is leaking or short-circuited, please check the leakage and eliminate the short-circuit.

　　6. ​​The uneven distribution of indoor airflow velocity causes dead angles and solutions.

　　① If the airflow organization design is not well considered, adjust the position of the air supply outlet or increase the number of air supply outlets according to the measured airflow distribution diagram.

　　② The air volume of the air outlet is not adjusted uniformly and does not meet the design value. The air volume of each air outlet should be adjusted to meet the design requirements.

　　 Common fault judgment methods of central air-conditioning-see

　　 Carefully observe the working conditions of each part of the air conditioner, focusing on the three parts of the electrical system, ventilation system and refrigeration system to determine whether they are working properly. Observe whether the fuse of the electrical system is blown, whether the insulation of the electrical wire is intact, whether the circuit board is broken, whether the connection is loose, etc.; observe whether there is too much dust in the air filter, heat exchanger coil and fins. Whether the air outlets and air outlets are unblocked, whether the fans and fan blades are operating normally, etc.; observe whether there are cracks, damage, frost and condensation in the pipes of the refrigeration system, and whether there are any between the refrigeration pipes, the pipes and the shell, etc. Friction and friction.

　　 Common fault judgment method of central air conditioner-listen

　　 Turn on the power and listen to whether the air conditioner compressor is running normally, whether there is abnormal sound, whether the fan is running, whether there is noise, whether the noise is too loud, etc. During the operation of the air conditioner, under normal circumstances, the vibration is slight and the noise is small, generally below 50DB.

　　 Common fault judgment method of central air conditioner-touch

　　 Under normal circumstances, the temperature of the condenser gradually decreases from top to bottom, and the temperature of the lower part is slightly higher than the ambient temperature. Under normal circumstances, putting a finger dipped in water on the surface of the evaporator will feel cold and sticky. The capillary tube at the dryer and outlet should feel warm under normal circumstances. The temperature of the suction pipe 200mm away from the compressor should be similar to the ambient temperature under normal conditions.

　　 Common fault judgment method of central air-conditioning-test

　　In order to accurately judge the nature and location of the fault, it is often necessary to use instruments and meters to check and measure the performance parameters and status of the air conditioner. For example, use a leak detector to check for refrigerant leakage; use a multimeter to measure whether the power supply voltage, the ground current of each terminal and the operating current meet the requirements, and the air conditioner controlled by a computer should also measure whether the potential of each control point is normal.

　　 Common fault judgment methods of central air conditioning-analysis

　　 The results obtained by the above-mentioned several inspection methods can only reflect a certain partial state. The various parts of the air conditioner are related to each other and affect each other. One failure phenomenon may have multiple causes, and one cause may also cause multiple failures. Therefore, it is necessary to conduct a comprehensive comparative analysis of local factors, so as to fully and accurately determine the nature and location of the fault.