Air Filter International Classification Standards

FOR PRE & FINE FILTERS

The standards for Pre-filters and Fine filters used in air filtration systems are primarily defined by international and regional organizations. Here are the commonly referenced standards:

1. EN 779 (Replaced by ISO 16890 in 2018) INHOUSE TEST LAB CALIBRATED NABL EQUIVALENT

 

  • EN 779:2012 classified filters based on their minimum efficiency at removing particulate matter. It divided them into groups such as G1-G4 for pre-filters and M5-M6 for fine filters.
  • This standard has been superseded by ISO 16890, which provides a more comprehensive approach.

2. ISO 16890: Air Filters for General Ventilation

  • ISO 16890 classifies air filters into four groups based on their ability to filter particles of different sizes:
    • Coarse filters: Often used as pre-filters, capturing large particles (ISO Coarse 30%-90%).
    • ePM10, ePM2.5, and ePM1 filters: Fine filters targeting particles ≤10 µm, ≤2.5 µm, and ≤1 µm, respectively.
  • Pre-filters: Typically classified as ISO Coarse filters.
  • Fine filters: Typically fall into the ePM categories.

3. IS 17570: Air Filters for General Ventilation (Latest equivalent to ISO 16890) INHOUSE TEST LAB CALIBRATED FOR COARSE GRADE AS OF NOW NABL EQUIVALENT

  • ISO 16890 classifies air filters into four groups based on their ability to filter particles of different sizes:
    • Coarse filters: Often used as pre-filters, capturing large particles (ISO Coarse 30%-90%).
    • ePM10, ePM2.5, and ePM1 filters: Fine filters targeting particles ≤10 µm, ≤2.5 µm, and ≤1 µm, respectively.
  • Pre-filters: Typically classified as ISO Coarse filters.

Fine filters: Typically fall into the ePM categories


 

4. ASHRAE 52.2: Method of Testing General Ventilation Air-Cleaning Devices INHOUSE TEST LAB CALIBRATED NABL EQUIVALENT

 

  • Filters are rated using a Minimum Efficiency Reporting Value (MERV) scale (1-16).
    • Pre-filters: Typically MERV 1–8.
    • Fine filters: Typically MERV 9–16.
  • MERV ratings correlate to the filter’s efficiency at capturing particles within specific size ranges.

5. INDIAN STANDARDS (IS) INHOUSE TEST LAB CALIBRATED NABL EQUIVALENT

 

  • IS 7613:1975: Specification for air filters used in general ventilation and air conditioning.
  • India may also adopt ISO 16890 for consistency with global practices.

Recommendations for Selection

  1. Pre-filters: Designed to capture large debris and extend the life of finer filters. Examples: G3, G4 (EN 779) or ISO Coarse 60-90%.
  2. Fine filters: Target finer particles for better air quality, used in cleanrooms, hospitals, and electronics. Examples: M5, M6 (EN 779) or ePM10, ePM2.5, ePM1 (ISO 16890)

FOR HEPA FILTERS

The standards for HEPA filters (High-Efficiency Particulate Air filters) are well-defined by various international and regional organizations, focusing on particle retention efficiency, performance, and testing methods. Below are the most commonly referenced standards:


1. EN 1822: High-Efficiency Air Filters (EPA, HEPA, ULPA) INHOUSE TEST LAB CALIBRATED NABL EQUIVALENT

  • Widely used in Europe and globally recognized.
  • HEPA filters are classified based on their particle filtration efficiency:
    • H10 to H12: EPA (Efficiency Particulate Air filters).
    • H13 and H14: HEPA (High-Efficiency Particulate Air filters).
    • U15 to U17: ULPA (Ultra-Low Penetration Air filters).
  • Efficiency criteria:
    • H13: ≥ 99.95% (MPPS – Most Penetrating Particle Size).
    • H14: ≥ 99.995% (MPPS).
  • Includes tests for:
    • MPPS efficiency.
    • Pressure drop.
    • Leak testing.

2. ISO 29463: High-Efficiency Filters and Filter Media

  • Aligns with EN 1822 but structured differently.
  • Classifies filters as EPA, HEPA, and ULPA based on efficiency at capturing MPPS:
    • ISO 35E to ISO 40U:
      • ISO 35H (HEPA): ≥ 99.95%.
      • ISO 40H (HEPA): ≥ 99.995%.
  • Standardizes testing methods for particle filtration.

4. IEST-RP-CC001: HEPA and ULPA Filters

  • Used in industries like aerospace and pharmaceuticals (U.S.).
  • Classifies filters based on particle retention at 0.3 µm:
    • HEPA: ≥ 99.97%.
    • ULPA: ≥ 99.999%.
  • Specifies testing for penetration, airflow resistance, and uniformity.

 

Key Considerations for HEPA Filters

  1. Applications: Cleanrooms, healthcare facilities, pharmaceutical production, nuclear facilities, etc.
  2. Testing Methods:
    • MPPS testing (EN 1822, ISO 29463).
    • Particle challenge testing (IEST).
    • Leak testing to ensure no bypass.
  3. Certification: Filters should include test certificates specifying efficiency and performance metrics.

 

NOTE – Let us know if you’d like specific guidance or details on these standards.