Why does the ULPA report indicate the test air volume?

This question may seem basic, but it is critical in report interpretation and acceptance.

Both efficiency and resistance vary with airflow conditions. The efficiency of the same filter may be very good when measured at low air volume, but the performance will be different when it is switched to the designed air volume. The resistance increases directly with the air volume. If the test air volume is not included in the report, the efficiency data will lose the basis for comparison.

How to compare test air volume and label

After getting the report, first look at the test air volume above.

Check with product label. The rated flow rate on the report, the rated flow rate on the product label, and the data in the sample data should be consistent. If it doesn't match, you need to confirm which link is the problem.

Check with actual operating conditions. What is the design air volume of the project? At what air volume was the report measured? If the difference between the two is large, technicians are required to evaluate the impact of the difference on actual performance.

Do not infer operating conditions based on the model name alone. There may be different specification variants under the same model name, and the ratings may also be different. Reports should be associated with specific product specifications or numbers.

Why low air volume reporting is no substitute for design conditions

This is where things tend to go wrong the most.

Results obtained at lower flow rates do not automatically demonstrate performance at higher flow rates. The efficiency and resistance of the filter change with the air volume, and the relationship between the two is not linear. The value measured at low air volume is 99.9995%. It cannot be inferred that this value is also the same under the design air volume.

If the operating range of the equipment changes - such as frequency conversion speed regulation, switching between different working conditions - the complete curve of the product within the target range should be checked, and if necessary, the detection data of the corresponding working conditions should be supplemented.

Supporting For the system used by the FFU fan filter unit , the test air volume of the filter element should best correspond to the design air volume of the unit. Device-side applications such as For the EFU equipment-end fan filter unit , the operating air volume is often determined by the equipment operating conditions. The reported air volume conditions should also be considered together with the actual usage conditions.

How to make up for missing items

If the report does not indicate the test air volume, the solution is not to guess, but to make up for it.

Request additional records from suppliers. Including air volume, test conditions, and data correspondence.

Request for re-measurement. If the original test record cannot be traced, retest according to the agreed method.

Associate the results with the product serial number. The supplementary data should be able to correspond to specific physical objects, rather than a batch average.

Oral explanation alone cannot form a complete basis for acceptance. When there are missing items in the report, the report will be temporarily used as the only basis for judgment, and the judgment will be made after the report is complete. involving HEPA/ULPA air filter products of different grades have the same reporting requirements, and the specific criteria are implemented according to the project documents and corresponding standards.

Project judgment example

In a certain report, the efficiency is measured at 500 cubic meters per hour, and the resistance is measured at another air volume.

In this case, the two numbers cannot be directly put together as the performance of the same operating point. It is necessary to confirm what valid data corresponds to the design working conditions, or require the supplier to supplement efficiency and resistance data under the same working conditions.

If it is indeed impossible to supplement, the difference between the data conditions and the actual working conditions must be explained during the evaluation, and the data cannot be assumed to be applicable. For projects with strict acceptance requirements, such data gaps should be resolved before installation and not left until the operation stage. For the implementation method of specific testing items, please refer to the relevant instructions of ULPA factory testing.

Selection and Acceptance Checklist

Report cooperation on Aili Industry

The test air volume is stated in the report, which is the prerequisite for the data to be available.

Aili Industrial's manufacturing system covers filters, motors, fans, control systems and complete machine assembly, and can provide ULPA ultra-high efficiency filter and supporting air supply equipment. Product testing data will indicate the test conditions and corresponding air volume, filters and When the FFU fan filter unit and EFU are delivered together, the testing conditions of the complete machine and filter element can be checked uniformly.

Clarifying the design air volume, operating range and reporting requirements when enquiring, will help confirm the applicability of the data. Specific information shall be subject to the project agreement and contract documents.