How to maintain and care for a 100-level laminar flow hood daily?

The daily maintenance and care of a 100-level laminar flow hood directly affect its cleanliness and service life. It is necessary to operate in a standardized manner from multiple aspects such as cleaning, component inspection, and performance monitoring. The following is a detailed maintenance guide:
1. Daily/pre - and post-use maintenance
1. Surface cleaning
Cleaning of the operation area
Wipe the countertop, inner walls, observation Windows, and sliding doors with 75% ethanol or neutral disinfectant to remove dust, reagent residues, or microbial contamination.
If you come into contact with infectious samples (such as bacteria or cells), you should first disinfect with a chlorine-containing disinfectant (such as 0.5% sodium hypochlorite), and then wipe off the residue with clean water.
External cleaning
Wipe the outer shell of the equipment with a damp cloth. Avoid using corrosive cleaners (such as strong acids or strong alkalis) to prevent damage to the powder-coated or stainless steel surface.
2. Function check
Airflow and wind speed testing
After turning on the equipment for 30 minutes, observe whether the wind speed indicator light (if any) is normal, or bring a paper strip close to the edge of the operation area. If the paper strip moves evenly, it indicates that the airflow is stable. An anemometer can also be used for measurement. The wind speed should be maintained at 0.3-0.6m/s.
Lighting and sterilization system
Check whether the lighting in the operation area is bright (illuminance ≥300 lux), and whether the ultraviolet lamp (if any) is turned on normally (avoid direct vision during irradiation. It is recommended to irradiate for 30 minutes after daily use for sterilization).
Ii. Weekly/Monthly Maintenance Priorities
Filter and fan maintenance
The primary filter is cleaned
The primary filter (made of non-woven fabric) at the air inlet of the equipment should be taken out every week, rinsed with clean water, dried, and reinstalled (if it is a disposable filter element, it needs to be replaced periodically) to avoid dust accumulation affecting the air intake volume.
Fan and circuit inspection
Listen for any abnormal noise during operation (normal noise ≤65 decibels). If there is any abnormal noise or vibration, it may be due to loose screws of the fan or dust accumulation on the impeller, and the machine needs to be shut down for maintenance.
2. Sealing performance and pressure difference monitoring
Seal inspection
Check whether the silicone sealing strips of the sliding door and observation window are aged or cracked. If there is any damage, they should be replaced in time to prevent external contaminants from seeping in.
Differential pressure gauge reading
If the equipment is equipped with a differential pressure gauge, when the differential pressure increases by 50% compared to the initial value (for example, when the initial differential pressure is 20Pa and rises to 30Pa), it indicates that the HEPA filter is clogged. It is necessary to record and prepare for replacement.
Iii. Quarterly/Annual Deep Maintenance
1. Replace the high-efficiency filter (HEPA)
Replacement cycle
Under normal use, it should be replaced every 1 to 2 years. If highly contaminated samples are frequently processed or the differential pressure gauge reading exceeds the standard, it needs to be replaced in advance.
Replacement precautions
Turn off the power of the equipment, wear a dust mask and gloves, and avoid dust falling when disassembling the filter. The new filter element needs to be confirmed to match the model and the sealing rubber strip should be checked for integrity. After installation, an integrity test (such as scanning for leaks) should be conducted.
2. Performance verification and calibration
Cleanliness testing
Every year, a third-party institution is entrusted to test the cleanliness of the operation area with a dust particle counter. The 100-level standard requires that the number of particles ≥0.5μm be ≤3520 per cubic meter (ISO level 5).
Wind speed and airflow direction test
Measure the uniformity of wind speed at multiple points with a hot sphere anemometer (the deviation of wind speed at each point is ≤20%), and observe whether the airflow is unidirectional with a smoke generator to avoid pollution caused by vortices.
3. Electrical system maintenance
Check whether the power cord is aged, whether the grounding is good, and whether the circuit breaker and leakage protection device are functioning properly. It is recommended that a professional electrician conduct an inspection once a year.
Iv. Maintenance Suggestions for Special Scenarios
Biosafety type laminar flow hood
If dealing with pathogens (such as BSL-2 grade samples), the exhaust filter needs to be disinfected (such as by ozone fumigation) after each use, and the disinfection time and concentration should be recorded.
Regularly check whether the negative pressure system is functioning properly (the negative pressure value must meet the design requirements) to prevent the leakage of harmful aerosols.
2. Applications in the electronics/semiconductor industry
Wipe the countertop with an anti-static cloth every month and check whether the anti-static ion fan is effective (you can use a static tester to test that the countertop voltage is ≤100V).
Avoid placing magnetic tools or devices with strong electromagnetic fields on the countertop to prevent interference with the airflow or damage to electronic components.
V. Maintenance Records and Exception Handling
Establish a maintenance ledger.
Record the time and results of each cleaning, filter element replacement, and performance test to facilitate the traceability of equipment status, such as:
Test results on the replacement of consumables for the date maintenance project
On June 12, 2021, the primary filter was cleaned without a wind speed of 0.4m/s, which was normal
Handling abnormal situations
If a significant weakening of airflow or excessive cleanliness is detected, the machine should be stopped immediately to inspect the filter and seals. If necessary, contact the supplier for maintenance.
If the equipment has been out of use for a long time (more than one week), the power supply should be turned off and it should be covered with a dust-proof cloth. Before being reactivated, it should be run idle for 30 minutes and sterilized with an ultraviolet lamp.
Vi. Safety Operation Precautions
When maintaining, the power supply must be cut off and live operation should be avoided. When replacing filters or touching electrical components, it should be carried out by professionals.
Disinfectants should be diluted as per the instructions. Do not mix them (for example, mixing alcohol with chlorine-containing disinfectants may produce toxic gases).
Through systematic maintenance and care, the service life of the 100-level laminar flow hood can be extended, ensuring that it always operates in a high-cleanliness state and reducing the risk of experimental contamination or the production of substandard products.