independent air quality consultants

indoor air quality, environmental and ventilation hygiene

01322 273158


HEPA integrity testing; DOP & discrete particle counting

We can provide an adjunct service for HEPA Filters replacement and their integrity testing in Air Handling Units, UCVs and Cleanrooms. Our experienced team can help select, procure, install and test HEPA filters, taking full responsibility for their supply, replacement and certification.

Is HEPA Filter Integrity Testing required?

Yes:- HEPA filters can become blinded with particulate over time, increasing the resistance to airflow passing through them which means that differential pressure will increase. As this happens, the airflow through the filter will reduce, usually resulting in a reduction in air quality. All newly installed filters should have their integrity tested to ensure performance to the necessary standard.

Our routine verification and performance testing helps identify any issues and the best time to replace HEPA filters.

What is involved?

Selection of the correct type, grade and style of manufacture for the new HEPA is essential. Often these types of filters are bespoke and made to order with a possible 3 to 4 week lead time, whilst others may be in stock. The new replacement filters will have their integrity tested normally by DOP testing in operational conditions immediately after installation. The test is used to detect leaks and tests the filter, seals, housing and terminal ductwork. In addition to testing filter integrity, it ensures that all air entering the controlled environment passes through the HEPA filtration system. An aerosol is dispersed upstream of the filter and the downstream face, and filter seals are scanned for leaks.

How often does it need to be done?

Normally every 1 to 5 years but this will depend on pre-filtration standards, operational requirements and regular performance testing results.

How can AirisQ help with HEPA Filters?

Our experienced team of trained and qualified surveyors, assessors, engineers provides this added value adjunct service by selecting from the market the best quality HEPA filters and by using the latest calibrated instrumentation.

Benefits of using HEPA Filter Replacement and Integrity Testing

  • Ensures compliance by maintaining appropriate levels of cleanliness and air quality through replacing with new, and then testing if and as necessary.
  • Independent unbiased service, as we are not a filter supplier/manufacturer and we are not in the business of selling filters.