Air Filter Maintenance: Introduction to Filter Maintenance

Regular maintenance of air filters is essential to sustain clean air quality, ensure energy efficiency, and extend HVAC system and cleanroom life. Poorly maintained filters can
increase pressure drop, reduce airflow, and compromise compliance with ISO/EN/GMP
standards.

Safe Handling of Filters

• Handle filter cartons gently at all times.
• Keep cartons upright as marked with ‘This Side Up.
• Avoid dropping, bending, squeezing, or dragging filters.
• Handle only by the frame or designated edges never touch the media.
• Always wear clean gloves during handling
•  

Storage and Transportation Guidelines

• Store in a clean, dry indoor area, away from direct sunlight and moisture.

• Maintain storage conditions below 45°C temperature and 70% relative humidity to
  prevent media degradation.

• Stack cartons only on clean, flat surfaces -not more than 3 boxes high.

• Do not place heavy objects on cartons or sit/stand on them.

• Avoid open storage or exposure to chemicals.

• Follow FIFO (First In, First Out) to ensure shelf-life compliance.

• Transport filters upright and secured.

Installation Best Practices

• Inspect the installation site and filter holding frame before placement.

• Confirm correct filter type, grade, and airflow direction (as marked).

• Install gently do not bend, squeeze, or damage the filter media.

• Tighten clips or gaskets uniformly to prevent bypass leakage.

• Ensure the gasket forms a proper seal for 100% effective filtration.

• Never install damaged or used filters.

Cleaning & Maintenance (Pre and Fine Filters Only)

• Use a manometer or magnehelic gauge to check pressure drop before cleaning.
• Remove filters carefully and shift to a clean maintenance area.
• Clean using compressed air (≤2 bar) from the clean air side to dislodge dust.
• If washable:
  – Use mild detergent, rinse with clean water.
  – Dry in a shaded, clean environment at max 45°C for 1–2 hours.
  – Do not reuse until completely dry and undamaged.

Cleaning Frequency

Always prioritize pressure drop as the primary indicator for cleaning frequency.

HEPA and Minipleat Filters – Do Not Clean

• Do not wash, clean, or repair HEPA filters.

• Replace if:

  • Pressure drop exceeds design final limit (e.g., 450–750 Pa – specific limits may vary).

  • Filter fails DOP/Integrity Test.

• During inspection:

  • Check for side leaks—replace gaskets/seals using approved silicone if required.

  • Do not disturb the media or pleats.

Filter Replacement Guidelines

• Always perform replacements during non-operational hours.

• Use only Ultrafil-compatible filters as per system specifications

Do’s and Don’ts of Filter Maintenance

• Do’s

  • Inspect filters regularly and record readings.
  • Monitor pressure drop continuously.
  • Follow FIFO principle for stock rotation.
  • Use genuine Ultrafil filters for best results.

• Don’ts

  • Do not attempt to wash HEPA filters.
  • Do not run HVAC systems without filters in place.
  • Do not ignore sudden spikes in pressure drop or bypass leakage.
  • Do not store filters in humid or chemical-prone areas.

Common Issues and Troubleshooting

• High Pressure Drop Early: Possible dust load, improper grade, or air bypass.
• Bypass Leakage: Caused by loose frames or damaged gaskets.
• Damaged Media: Mishandling during transport/installation.
• Poor Air Quality Despite New Filters: Check upstream stages or housing leaks

Disposal / Scrappage

• Do not reuse failed filters, especially HEPA.

• Seal used filters in heavy-duty plastic bags immediately.

• Dispose of pre- and fine filters in a contamination-free manner.

• Follow local environmental and safety guidelines for disposal.

• For pharmaceutical/cleanroom use, treat used filters as biohazard waste.

• Follow national PCB/WHO guidelines

Maintenance Record and Documentation

• Maintain a log with:

  • Date of installation
  • Inspection/cleaning intervals
  • Pressure drop readings
  • Replacement date
  • Name of responsible person

(Ultrafil can provide standard log templates and digital record-keeping support.)

Conclusion

Following Ultrafil’s maintenance guidelines ensures:

• Reliable air quality performance
• Energy-efficient operation
• Compliance with global standards (ISO 16890, EN 1822, GMP)
• Extended equipment and system life