Most air purifiers remove pollutants from the air by filtration or by ionising molecules. The filtration system uses a fan to draw air into the machine before passing it through a series of filters. These are usually foam, fibreglass or charcoal, all of which are extremely porous. This allows small air particles to pass through but catches and holds larger dust particles. Air purifiers that only let through 0.03 per cent of particles that are 0.3 micrometers or larger are given a High Efficiency Particulate Air rating from the US Department of Energy. Ionising purifiers also draw air in using a fan. Once inside, larger particles such as pollen or dust molecules pass through an electrical field called a corona discharge. This adds or removes an electron from the molecule, giving it either a positive or negative charge. The charged molecules are then attracted to one of two charged metal plates inside the purifier where they stick, allowing the clean air to pass through.
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Bhavna Joshi
Most air purifiers remove pollutants from the air by filtration or by ionising molecules. The filtration system uses a fan to draw air into the machine before passing it through a series of filters. These are usually foam, fibreglass or charcoal, all of which are extremely porous. This allows small air particles to pass through but catches and holds larger dust particles. Air purifiers that only let through 0.03 per cent of particles that are 0.3 micrometers or larger are given a High Efficiency Particulate Air rating from the US Department of Energy. Ionising purifiers also draw air in using a fan. Once inside, larger particles such as pollen or dust molecules pass through an electrical field called a corona discharge. This adds or removes an electron from the molecule, giving it either a positive or negative charge. The charged molecules are then attracted to one of two charged metal plates inside the purifier where they stick, allowing the clean air to pass through.