How does a HEPA filter work?
Usually made from glass-fibre or PTFE materials, a HEPA air filter resembles randomly arranged strands. As particles range in size and texture, they require different trapping methods to be effectively removed. To answer the question ‘what does a HEPA filter do?’, see how it traps different types of particle pollutants:
- Larger particles: are trapped by and stick to the net-like structure of filter fibres.
- Smaller particles: follow airflow and are intercepted by the filter.
- Smooth particles: diffused air forces smooth particles to move erratically, causing them to collide with filter fibres and become stuck.
A gas-phase substance, formaldehyde is an exceptionally small particle that can evade conventional air filter standards. Found throughout the home, including in paint materials, wood, furniture and carpets, it reduces air quality and can continuously reoccur. Alongside a HEPA H13 standard filter and carbon filter, Dyson Purifier Hot+Cool™ Formaldehyde contains an SCO (Selective Catalytic Oxidisation) filter, which destroys formaldehyde4 and converts it into water and Co2.