What is Filtration?

Filtration refers to the mechanical or electrostatic capture of airborne particulates (e.g., dust, pollen, mould spores, and pollutants) via a porous medium (filter). In UK building practices, filtration is critical for maintaining healthy indoor environments, particularly in energy-efficient homes where airtightness can trap pollutants.

Explanation & Practical Applications:

  • Mechanical Filtration: Uses fibrous media (e.g., HEPA, MERV-rated filters) to physically trap particles. Common in HVAC systems and standalone air purifiers.
  • Electrostatic Filtration: Charges particles to attract them to oppositely charged plates (e.g., ionisers).
  • Carbon Filtration: Removes gases and odours via activated charcoal, useful in kitchens or areas with high VOC emissions.

UK Building Regulations & Standards:

  • Approved Document F (Ventilation, 2021): Recommends filtration where mechanical ventilation is used (e.g., MVHR systems) to prevent recirculation of pollutants.
  • BS EN 16798-3:2017: Covers ventilation and air filtration performance criteria.

Synonyms:

  • Air purification
  • Particle capture
  • Contaminant removal

Related Terms:

  1. Mechanical Ventilation with Heat Recovery (MVHR) – Balanced ventilation systems that filter incoming air while recovering heat.
  2. Indoor Air Quality (IAQ) – The overall healthiness of air inside buildings, influenced by filtration.
  3. Particulate Matter (PM2.5/PM10) – Microscopic pollutants targeted by filtration.
  4. Airtightness (Part L, Building Regs) – High-performance homes require effective filtration due to reduced natural ventilation.
  5. Ventilation Strategies (Approved Document F) – Guidance on integrating filtration into whole-house ventilation.
  6. Filter Efficiency (MERV/HEPA Ratings) – Standards defining filter performance.
  7. Volatile Organic Compounds (VOCs) – Gaseous pollutants mitigated via carbon filtration.