Troubleshooting And Solutions for Unstable Air Velocity in Fume Hoods?

Troubleshooting

Inspection of fans and air ducts

Aging or malfunction of the fan: Some old fume hoods have aged fans or air ducts, which may cause fluctuations in wind speed. It is necessary to check whether the bearings of the fan are worn. If they are worn, the bearings need to be replaced. Check whether the fan blades are balanced. If they are not, adjust the blade balance or replace the fan blades.

Air duct blockage: The air ducts of fume hoods may be blocked by dust, debris, etc., resulting in reduced or unstable air velocity. Check if there is any blockage in the air duct. If so, you can use a vacuum cleaner, brush or other tools to clean it.

Air duct leakage inspection: Check whether there are any cracks or air leaks at each connection point of the working pipeline. If there are any air leakage points, they need to be repaired in time to ensure that the air volume meets the design requirements.

Control system inspection

Inverter issue: Check whether the inverter is working properly, including whether its function Settings are correct and whether there is a three-phase power output at the output end. If the frequency converter malfunctions, it may affect the fan speed, thereby causing unstable wind speed. Professional personnel should be contacted for maintenance.

Sensor failure: Some fume hood air velocity display instruments have calibration errors or sensor malfunctions, which can lead to abnormal air velocity readings. Sensors need to be calibrated or replaced regularly to ensure the accuracy of wind speed monitoring.

Electrical circuit inspection: Check whether the wires along the route are damaged and whether the resistance value of the motor coil matches the indicated power. If the wires are damaged or the resistance value of the motor coil is abnormal, it may affect the normal operation of the fan and cause unstable wind speed.

Troubleshooting

Maintenance of fans and air ducts

Fan maintenance: Regularly conduct detailed inspections and maintenance of the fan, promptly replace severely worn parts, and at the same time, maintain the motor to ensure its normal operation, thereby maintaining the fan's good air extraction performance.

Air duct cleaning: Regularly clean the ventilation ducts. Professional duct cleaning equipment can be used to go deep into the ducts and remove the dust and dirt adhering to the duct walls, thereby reducing ventilation resistance and allowing the gas to flow freely without hindrance.

Air duct sealing treatment: For the air leakage points at the connection points of the air ducts, materials such as sealant and sealing strips can be used for sealing treatment to ensure good sealing of the air ducts and prevent air leakage from causing unstable wind speed.

Control system repair and calibration

Inverter repair: If the inverter malfunctions, it is necessary to contact a professional for maintenance to ensure its normal function and accurate control of the fan speed.

Sensor calibration or replacement: Regularly calibrate the wind speed sensor. If the sensor is damaged, a new one should be replaced in a timely manner to ensure the accuracy of wind speed monitoring, thereby providing a reliable basis for the wind speed adjustment of the fume hood.

Electrical circuit repair: If damaged wires are found, new ones should be replaced in a timely manner. If the resistance value of the motor coil is abnormal, it is necessary to further check whether the motor has a fault. If necessary, replace the motor to ensure the normal operation of the electrical circuit and guarantee the stable operation of the fan.