Learn About Air Purification

Understand the science behind clean indoor air. Learn how HEPA filtration, proper ventilation, and adequate ACH protect your family from smoke, allergens, and airborne pathogens.

Air Purification 101

Air purification works by continuously filtering室内 air through mechanical filters that capture particles. HEPA (High-Efficiency Particulate Air) filters are the gold standard, capturing 99.97% of particles 0.3 microns or larger.

Key Concepts

  • CADR (Clean Air Delivery Rate): Measures the volume of filtered air delivered, typically in m³/h or CFM. Higher CADR means faster air cleaning.
  • ACH (Air Changes per Hour): How many times the entire room volume is filtered per hour. Target 5-12 ACH for effective purification.
  • MERV Rating: Minimum Efficiency Reporting Value rates filter effectiveness on a scale of 1-16. HEPA is equivalent to MERV 17+.
  • Filter Types: Mechanical filters (HEPA), activated carbon (VOCs/odours), UV-C (pathogens in some units).

Common Indoor Pollutants

Particulate Matter (PM)

PM2.5: Fine particles 2.5 microns or smaller from smoke, pollution, cooking. Penetrate deep into lungs. HEPA filters remove effectively.

VOCs

Volatile Organic Compounds: Gases from paints, cleaning products, furniture. Require activated carbon filters. Source control is best.

Allergens

Pollen, pet dander, dust mites: Typically 1-100 microns. HEPA filters capture effectively. Regular cleaning also helps.

Smoke

Tobacco, wildfire, cooking smoke: Mix of particles and gases. HEPA for particles, carbon for odours. High ACH recommended.

Airborne Pathogens Overview

Many respiratory illnesses spread through airborne transmission. While air purification is not a medical treatment, high-efficiency filtration can reduce concentrations of airborne pathogens including:

  • • Common colds and influenza: Viruses spread via respiratory droplets and aerosols
  • • RSV (Respiratory Syncytial Virus): Particularly concerning for infants and elderly
  • • Streptococcus (strep throat): Bacterial pathogen in respiratory droplets
  • • COVID-19: SARS-CoV-2 transmission reduced with adequate ventilation and filtration
  • • Measles: Highly contagious; can remain airborne for hours
  • • Tuberculosis: Airborne bacterial disease requiring ventilation control
Important: This information is educational only and not a substitute for medical advice. Air purification is one layer of protection alongside vaccination, hygiene, and medical care. Consult healthcare professionals for medical guidance.

Ventilation vs Filtration

Ventilation

Replaces indoor air with outdoor air. Effective when outdoor air is clean. Energy-intensive in extreme weather. Natural (windows) or mechanical (HVAC).

Filtration

Cleans existing indoor air by removing particles. Works regardless of outdoor air quality. Energy-efficient. Requires filter maintenance.

Source Control

Prevent pollutants at source. Most effective strategy. Examples: no smoking indoors, proper ventilation when cooking, low-VOC products.

Glossary

HEPA

High-Efficiency Particulate Air filter that captures 99.97% of particles 0.3 microns or larger.

CADR

Clean Air Delivery Rate - measures the volume of filtered air delivered by an air purifier, typically in m³/h or CFM.

ACH

Air Changes per Hour - the number of times the entire volume of air in a room is filtered per hour.

PM2.5

Particulate Matter 2.5 microns or smaller - fine particles that can penetrate deep into lungs.

VOC

Volatile Organic Compounds - gases emitted from certain solids or liquids, including paints and cleaning products.

MERV

Minimum Efficiency Reporting Value - rates air filter effectiveness on a scale of 1-16.

CFM

Cubic Feet per Minute - airflow measurement commonly used in the US.