EN1822 is a European standard for air filters. It specifies the performance requirements and testing methods for high-efficiency particulate air (HEPA) and ultra high efficiency particulate air (ULPA) filters. This standard is crucial for ensuring the quality and performance of air filtration equipment, especially in places that require extremely high air quality, such as cleanrooms, laboratories, hospital operating rooms, etc.
Overview of European High Efficiency Filter Standard EN1822
The European standard EN1822 was drafted by the CEN/TC195 technical committee, which focuses on "air filters for general air purification". The German Standardization Committee (DIN) serves as the chairman of the committee. The EN1822 standard provides detailed performance testing methods for high-efficiency particulate air (HEPA) and ultra high efficiency particulate air (ULPA) filters. This standard consists of five parts, covering grading, performance testing, labeling, aerosol generation and measurement, single filter paper testing, filter element leakage determination, and full efficiency determination.
Composition of EN1822 standard
Part 1: Refers to the classification, performance testing, and labeling of filters.
Part 2: Describe the generation of aerosols, measurement equipment, and particle counting statistics.
Part 3: Focus on performance testing of individual filter paper.
Part 4: Detailed explanation of the method for measuring filter element leakage (scanning method).
Part 5: specifies the method for measuring the overall efficiency of filter elements.
Particle counting method
The EN1822 standard uses particle counting as the basis, which meets the needs of most application scenarios. Unlike earlier national standards, the EN1822 standard determines overall efficiency based on the particle count of the most penetrable particle size (MPPS, range: 0.15/1 µ m) rather than the total particle mass. This method can measure ultra efficient filters, which previous experimental methods could not achieve due to sensitivity limitations.
Testing system and process
The testing system includes components such as primary filters, medium filters, fans, air heaters, high-efficiency filters, and test pipelines. The test airflow is heated by a heater to maintain a temperature between 18-28 degrees. The testing points are located upstream and downstream of the filter to determine particle concentration and filter penetration rate. Differential pressure gauge is used to measure the resistance of filters.
In the testing process, a diluter is added between the upstream counters to dilute the high concentration aerosol to a measurable concentration. Downstream testing will be conducted directly. The test air volume needs to be adjusted according to the rated air volume of the filter to ensure that the deviation does not exceed ± 3%. Aerosols need to be thoroughly mixed in the testing section to ensure uniformity of the test.
Scanning testing system
The scanning testing system ensures that the air passes through a high-efficiency filter and is divided into two paths: one path passes through a flow meter to reach the tested filter, and the other path forms an air curtain to prevent surrounding particles from entering the testing area. The computer records and processes various parameters, controls the scanning mechanism to drive the scanning head to move on the outlet side of the filter, and captures the concentration of leaked particles.
Requirements for scanning head
There are strict requirements for the size, inlet area, distance from the filter, movement speed, and temperature and humidity of the test air of the scanning head to ensure the accuracy of the test.
Efficient filter scanning test bench pipeline system
The pipeline system includes components such as coarse filter, medium filter, fan, air heater, air flow control damper, high-efficiency filter, aerosol inlet test tube, test airflow, air curtain airflow, etc. The design of the system aims to ensure the accuracy and repeatability of testing.
Through these detailed testing methods and system requirements, the EN1822 standard ensures that the performance evaluation of high-efficiency filters is both accurate and reliable, meeting the high standard requirements for air purification in different industries.
