What are the details to pay attention to when installing a ductless fume hood 2/2

4. Sealing inspection
-Use a smoke generator or aerosol generator to test the sealing of the cabinet, with a focus on checking the door seams, filter frames, and interfaces. If there is a leak, it needs to be resealed.
-After closing the cabinet door, use an anemometer to check whether the surface wind speed is uniform (with a deviation of ≤ 10% at each point).
3、 Debugging and testing
1. No load operation test
-Turn on the fan and run it for 30 minutes to observe for any abnormal vibration or noise (normal noise ≤ 65dB).
-Detecting filter pressure difference: The initial pressure difference should be close to the theoretical value (such as HEPA filter pressure difference ≤ 250Pa). If it is too high, check whether the installation is tight.
2. Load simulation test
-Place a small amount of low concentration reagent (such as ethanol) in the cabinet, turn on the fan and observe the adsorption effect of the filter to ensure that there is no odor leakage.
-Use a particle counter to detect downstream air cleanliness (particle count should be ≤ 3500/m ³, in accordance with ISO 14644-1 standard).
4、 Daily maintenance and precautions
1. Filter maintenance
-The lifespan of HEPA filters is usually 1-2 years, and activated carbon filters need to be replaced every 6 months (adjusted according to usage frequency).
-Regularly check the differential pressure gauge and replace the filter immediately when the differential pressure exceeds twice the initial value.
2. Cleaning and disinfection
-Wipe the interior of the cabinet with a mild cleaning agent every month to avoid clogging the filter; The surface of stainless steel can be disinfected with alcohol.
-The fan module is cleaned of dust every quarter, and the bearings are lubricated once a year.
3. Safety Warning
-It is prohibited to use open flames or high-temperature equipment (such as spray lamps) inside the cabinet to prevent ignition of the filter.
-When handling radioactive materials or highly active chemicals, an additional dedicated adsorption layer is required.
5、 Common Problems and Solutions
-Insufficient wind speed: Check the fan speed, filter blockage, or whether the cabinet door is fully closed.
-Excessive noise: Check for worn fan bearings, cabinet resonance, or uneven installation.
-Odor leakage: It may be due to filter failure or aging sealing strips, which need to be replaced in a timely manner.
The installation of ductless fume hoods requires comprehensive consideration of spatial layout, equipment compatibility, and operational safety. By standardizing installation, regular maintenance, and reasonable use, it can ensure long-term efficient operation and provide reliable safety protection for the laboratory. It is recommended to have a professional engineer complete the installation and regularly contact the manufacturer for performance testing and maintenance.