How to choose air filters for a clean room?
Primary effect filter
Primary filter: It is mainly used to remove large particles in the air, such as dust and hair. The structure of the primary filter is simple, easy to replace and clean, and is the first line of defence for clean room air purification.
Medium Efficiency Filters
Used to remove medium-sized particles from the air, further reducing the dust load entering the high-efficiency filter. Medium efficiency filters typically have higher filtration efficiencies and a longer service life.
High Efficiency Filter
It is the core component of a clean room and is used to remove tiny particles in the air, such as bacteria, viruses and pollen. HEPA filters have a very high filtration efficiency, which ensures that the air quality in the cleanroom meets the required standards.
Filter performance parameters
Filtration efficiency: refers to the ability of the filter to remove particles in the air. The higher the filtration efficiency, the better the air quality in the clean room.
Resistance: refers to the pressure loss generated when air passes through the filter. The lower the resistance, the lower the energy consumption of the filter, and the lower the operation cost.
Dust holding capacity: the total amount of particles that the filter can hold before reaching the specified resistance. The larger the dust holding capacity, the longer the service life of the filter.
Cleanroom Requirements
Cleanliness level: According to the use and requirements of the cleanroom, choose the appropriate cleanliness level. For example, for laboratories or production lines that require high cleanliness, high-efficiency filters should be selected; for areas with general cleanliness requirements, intermediate or primary filters can be selected.
Temperature and humidity requirements: According to the temperature and humidity requirements of the clean room, select the appropriate filter material. For example, in high temperature and high humidity conditions, it is appropriate to choose metal partition and metal frame filters; in low temperature and low humidity conditions, it is necessary to consider the insulation and anti-freezing performance of the filter.
Fire protection requirements: For cleanrooms that require fire protection, filter materials with fire protection properties should be selected. For example, all materials of the filter should be non-combustible to ensure that the fire will not aggravate the fire when it occurs.
Anti-corrosion requirements: For cleanrooms with anti-corrosion requirements, filter materials with anti-corrosion properties should be selected. For example, filters using plastic dividers and plastic frames can resist corrosion by chemicals.
Filter Configuration
Filter combination: According to the cleanliness requirements and air flow in the clean room, the combination of primary, medium and high efficiency filters can be reasonably configured. For example, for a class 100 clean room, the combination of plate G4 (F5) + bag F7 (F8) + bag F9 + plate H13 + (FFU filtration unit at the end of the air duct) can be used.
Filter Layout: Reasonable layout of the filter can ensure that the air is evenly distributed in the clean room to avoid local pollution. For example, setting filters at the air supply outlet and air return outlet of the clean room can ensure that the air circulates in the clean room and improve the air purification effect.
Other Precautions
Filter Replacement Cycle: According to the service life of the filter and the operation requirements of the cleanroom, replace the filter regularly. Avoid filter clogging or failure resulting in a decline in air quality in the clean room.
Filter maintenance: Clean and inspect the filter regularly to ensure the performance and efficiency of the filter. For washable filters, they should be cleaned according to the manufacturer's cleaning guidelines; for non-washable filters, they should be replaced in time.
Filter selection: When selecting filters, reference should be made to the performance parameters and selection guidelines provided by the manufacturer, combined with the specific requirements of the cleanroom for selection. Meanwhile, professional air purification engineers or technical teams can also be consulted for more professional advice and support.
