HEPA (High Efficiency Particulate Air) Filter

HEPA filters are one of a type of air purifiers that applies the principle of trapping unwanted air particles such as pollens and pollutants in a series of randomly placed fibre networks arranged in mats. The mats work in conjunction with the flow of air passing through them to trap unwanted particles in three different ways. The airflow passes by a fibre in such proximity that the particle is attracted to it and sticks. Large particles in the airflow are embedded directly into the fibre.  Particles in the airflow collide with gasses emitted by the smaller particles that stuck to fibres and were trapped causing a disruption in the path of the particle which then usually leads to the particle becoming either embedded in the fibres or stuck to them.

HEPA filters are only one of a larger family of air purifiers. In general they all work towards the same goal of removing contaminants from the air. Air purifiers can be a godsend for allergy sufferers and asthmatics in that they help alleviate symptoms caused from hay fever and second hand smoke.