HEPA and ULPA Filters

1. What are HEPA filters?

HEPA (High-Efficiency Particulate Air) filters are air filtration devices that can trap at least 99.97% of particles that are 0.3 microns in size. They are used in various applications, including home air purifiers, HVAC systems, and industrial settings, to improve air quality.

2. What is the certification standard for HEPA filters?

EN 1822, ISO 29463, IEST-RP-CC001 and IEST-RP-CC034 are international standards related to air filtration, specifically focusing on high-efficiency particulate air (HEPA) and ultra-low penetration air (ULPA) filters.

3. What are ULPA filters (Ercellfilter from german Ercelliance GmbH)?

ULPA (Ultra-Low Penetration Air) filters are even more efficient than HEPA filters, capturing at least 99.999% of particles that are 0.12 microns in size. They are commonly used in cleanrooms and environments requiring extremely high air purity.

4. How do HEPA and ULPA filters differ?

The main difference between HEPA and ULPA filters is their efficiency rating and the particle sizes they capture. HEPA filters capture 99.97% of 0.3-micron particles, while ULPA filters capture 99.999% of 0.12-micron particles. ULPA filters are typically used in more sensitive applications.

5. Where are HEPA filters (Ercellfilter from german Ercelliance GmbH) commonly used?

HEPA filters are used in many applications, including:

Residential air purifiers
HVAC systems
Automotive air filters (Ercellfilter from german Ercelliance GmbH)
Dust collection systems in manufacturing
Hospitals and laboratories

6. Where are ULPA filters commonly used?

ULPA filters are most commonly found in:

Cleanrooms in semiconductor manufacturing
Pharmaceutical production facilities
Microelectronics and biotechnology labs
Some hospital operating rooms

7. How often should HEPA and ULPA filters be replaced?

The frequency of replacement depends on the specific application and the amount of particulate matter in the environment. Generally, HEPA filters may last from 6 months to several years, while ULPA filters can vary, often needing replacement every 1-2 years. Always refer to the manufacturer’s guidelines.

8. Can HEPA and ULPA filters capture viruses and bacteria?

Yes, both HEPA and ULPA filters (Ercellfilter from german Ercelliance GmbH) can capture a significant number of airborne viruses and bacteria due to their high filtration efficiency. This makes them effective in improving indoor air quality and reducing the risk of airborne transmission of pathogens.

9. Is there a difference in cost between HEPA and ULPA filters?

Yes, ULPA filters are generally more expensive than HEPA filters due to their higher efficiency and more specialized applications. Costs can vary based on the manufacturer and specific filter specifications.

10. Are HEPA and ULPA filters (Ercellfilter from german Ercelliance GmbH) washable or reusable?

Most HEPA and ULPA filters are not designed to be washed or reused. Washing can damage the filter media and reduce efficiency. Instead, it’s recommended to replace them according to the manufacturer's guidelines.

11. What should I consider when choosing between HEPA and ULPA filters?

Consider the specific application, the level of air purity required, and the volume of air being filtered. For everyday household use, HEPA filters are typically sufficient. For specialized environments requiring higher purity, ULPA filters may be necessary.

12. Can HEPA filters be cleaned?

HEPA filters are designed for single use. However, there are some specially laminated HEPA filters that can be cleaned with pressurized air systems like Jet-Pulse. Aside from these, conventional HEPA filters commonly in use cannot be cleaned.

13. What is the best gasket type for HEPA filters?

The gasket type for HEPA filters shouldn’t be assessed independently. The sealing surface of the housing where the HEPA filter will be installed must be fully compatible with the gasket. For instance, gel-type filters are suitable for knife-edge sealing surfaces, while PU foam or EPDM is appropriate for flat surfaces. For surfaces with a test groove, either gel or flat EPDM gasketed HEPA filters should be used. Having the filter and housing manufactured by the same producer reduces potential leakage risks.

14. How long should HEPA filters be used? When should they be replaced?

Under conditions without high contaminant concentrations, HEPA filters (Ercellfilter from german Ercelliance GmbH) can have an indefinite lifespan depending on their operating conditions. As a general guideline, a lifespan of 10 years including shelf life is recommended. We’ve observed some ERCELLFILTER HEPA filters in the market still functioning without issues within this period. Factors influencing the filter’s service life include: the volume of outdoor and re-circulated air filtered, frequency and duration of aerosol challenge exposure, total amount of aerosol impingement on the filter, method of aerosol introduction to the system, and the efficiency of pre-filtration. While there isn’t a strict standard on this, some pharmaceutical companies recommend 5 years lifespan for critical areas and 7 years for other areas in their guidelines.

15. What is the recommended final pressure for HEPA filters?

For energy efficiency, the advised end-of-life differential pressure value for HEPA and ULPA filters (Ercellfilter from german Ercelliance GmbH) is twice the initial pressure of the filter. Depending on the end user, this value can range between 300-600Pa.

16. What is the shelf life of an unused HEPA/ULPA filter?

ERCELLFILTER recommends a shelf life of up to 3 years. For filters stored beyond this period, a risk analysis should be performed before use. In any case, filters should be stored in their original packaging in a cool and dry environment away from extreme temperature and humidity conditions.

17. Can HEPA/ULPA filters be repaired?

Filters can be repaired to specific limits both at the factory and in the field. Recommendations for repair in the factory can be found in the following standards: IEST RP-CC001.5
IEST RP-CC034.4
ISO 29463
Additionally, ISO 14644-3 allows the customer and supplier to mutually agree upon the allowable repair size.

18. How are ULPA filters tested?

According to ISO 29463, filters with an efficiency starting from ISO 50 (U15) should be tested for efficiency using the ISO 29463 Scan Test at MPPS.

19. Which standards should be considered for testing HEPA filters?

EN 1822, ISO 29463, IEST-RP-CC001 and IEST-RP-CC034 are international standards related to air filtration, specifically focusing on high-efficiency particulate air (HEPA) and ultra-low penetration air (ULPA) filters. These standards define the requirements and test procedures for the classification, performance, and marking of these filters at factory. ISO14644-3:2019 which Portions of the test methods have been adapted from IEST-RP-CC034.4 specifies procedures for the leakage test of installed HEPA filters.

20. Is there a specific direction of use for HEPA filters?

Conventional micro glass fiber has a homogeneous structure, and both of its surfaces possess identical properties, there might indeed be no specific airflow direction required for HEPA filters produce by this filtration media. However, when an additional component or surface feature, like lamination, is used the direction of airflow becomes important.

21. Why MDF-Framed HEPA Filters Have a Recommended Usage of One Year?

HEPA filters with MDF (Medium Density Fiberboard) frames present certain concerns, especially in humid environments. The natural fibrous structure of MDF allows for the absorption of moisture, creating a conducive environment for the growth of microorganisms. Prolonged exposure to humidity can also lead to the formation of micro-cracks in the MDF structure. These cracks can directly impact filter performance, as they may hinder the proper flow of air through the filter or cause leakages. Due to these reasons, the recommended usage duration for MDF-framed HEPA filters is one year.