How to determine the air volume for ULPA efficiency test? Rated and actual operating conditions description

The air volume for ULPA filter efficiency testing should be determined based on the adopted standard, product rated operating conditions and project agreement, and clearly recorded. Changes in test air volume may affect face velocity, resistance, and interpretation of test results. The efficiency value on the test report does not exist in isolation, it corresponds to a certain test air volume; the resistance value on the report also corresponds to a certain test air volume. If the two air volumes are not the same, high efficiency and low resistance cannot be compared together. Aili Industry isIn the testing data organization of the ULPA ultra-high efficiency filter , the efficiency and resistance data are each marked with the corresponding test air volume, and the rated conditions and actual working condition range are presented separately. The project party does not need to calculate what conditions each value corresponds to.

1. Clarify the rated and actual working conditions: each of the two air volumes has its own purpose

The rated conditions are used for nominal and supply verification, and the actual usage range is used for system matching; differences between the two should be distinguished in the data, and cannot be marked with just one fuzzy air volume.

The rated air volume is the reference value calibrated by the product under standard conditions, and is used to determine whether the nominal performance is achieved during supply acceptance. The actual operating air volume is the air volume that actually passes after the filter element is installed in the equipment. It may be higher or lower than the rated value, depending on the fan operating point and system resistance. Aili Industry isThe HEPA/ULPA filter technical information lists the rated conditions and recommended operating range in columns.When the FFU fan filter unit is matched, the performance data of the filter element at the air volume can be checked according to the actual working point. The relationship between levels and filtering requirements can be found inISO cleanliness level comparison。

2. Unify the units and objects: the air volume of the whole unit, the wind speed of the filter surface and the speed of the filter material sample are not the same thing

Check whether it is the volume flow rate of the entire unit, the average velocity of the filter surface or the velocity of the filter material sample, and indicate the effective area. Wind speeds of different objects cannot be directly replaced.

The unit of the entire air volume is cubic meters per hour, the unit of the average wind speed on the filter surface is meters per second, and the filter material sample speed corresponds to a smaller test area. The three are converted to each other through the effective filter area, but the area diameter must be consistent during conversion. Aili Industry isThe test report of the ULPA ultra-high-efficiency filter also indicates the test air volume and the corresponding effective filtration area. The efficiency and resistance data correspond to the entire unit to avoid mixing the filter material sample data with the complete machine data. The relationship between face wind speed and resistance can be referred toHEPA FAQs and Selection Guide。

3. Determine the scope of verification in the agreement: regular delivery and special multi-working conditions should be agreed separately

Regular delivery and special multi-working condition verification should be agreed upon separately, and applicable curves and reports should be provided to avoid subsequent requirements to use single point data to prove all flow performance.

If the project only requires efficiency verification under rated air volume, it can be supplied and tested according to the standard; if the actual operating air volume range is wide and verification needs to be performed at multiple air volume points, it should be agreed in advance in the purchase agreement. Aili Industry isIn the non-standard ULPA filter project, multiple working condition test points can be agreed upon according to the agreement, and the test report lists the efficiency and resistance data of each air volume point separately, instead of using the data of one point to cover all working conditions. For the correspondence between test conditions and acceptance, please refer toULPA ultra-high efficiency filter FAQ and selection guide。

4. When the actual equipment requires a larger air volume than the rated volume, it should be re-evaluated rather than expanding the scope of the report.

When the actual equipment requires a larger air volume than the rated one, the model and test conditions should be re-evaluated rather than directly expanding the scope of the report. Operating beyond the rated air volume will increase the face wind speed and resistance. The actual performance of efficiency and resistance may be different from the rated data.

Aili Industry isFFU fan filter unit andWhen matching the fan filter unit at the EFU equipment end , the data of the filter element at the air volume can be checked according to the actual working point of the equipment.The FFU computer group control system records the actual operating air volume for easy comparison. The relationship between working point and filter matching can be referred toFFU FAQ and technical support。

5. Related questions and answers

Can passing the low air volume test prove that the high air volume is qualified?
It cannot be directly inferred, and it should be confirmed that the target operating conditions have been covered by applicable data and verification.

What should I do if the rated air volume is inconsistent with the actual working condition air volume?
The performance data of the filter element at the actual operating point should be checked to confirm that the efficiency and resistance are still within the applicable range at this air volume.

The efficiency report only labels one air volume, is it enough?
If the actual operating air volume is consistent with the test air volume, it is sufficient; if the actual air volume deviates from the test point, the data at this air volume needs to be supplemented.

6. Related articles

ULPA ultra-high efficiency filter FAQ and selection guide

ULPA ultra high efficiency filter

FFU FAQ and technical support

HEPA FAQs and Selection Guide

7. Key points for selection and acceptance inspection

8. Product matching and technical support from Aili Industrial

Aili Industry isThe HEPA/ULPA filter technical information lists the rated conditions and recommended operating range in columns.The test report of the ULPA ultra-high-efficiency filter also indicates the test air volume and the corresponding effective filtration area, and the efficiency and resistance data correspond to the entire unit;Non-standard ULPA filter projects can stipulate multiple working condition test points according to the agreement, and the data of each air volume point will be presented in separate rows.FFU fan filter unit andWhen the EFU equipment-end fan filter unit is matched, the filter element data under the actual working point of the equipment can be checked.The FFU computer group control system records the actual operating air volume for easy comparison. Provide process objectives, installation drawings, operating conditions and acceptance requirements, and can further communicate ULPA standard specifications, non-standard interfaces, samples and batch matching. The specific parameters and test range are based on the confirmed model and technical documents.