Most air purifiers are based on air recirculation. Therefore, air purifiers are equipped with a variety of filters through which air from the outside environment is regularly filtered to bring clean air into the room. For complete purification, ventilation of the room must be kept to a minimum. Ventilation should be intermittent, as air recirculation is only effective in enclosed rooms. The choice of purifier is critical. The choice depends primarily on the size of the room in which the purifier is placed. The size of the room should be chosen so that the air capacity of the purifier is twice the volume of the room. If you suffer from various allergies, especially pollen, it is advisable to opt for at least three times the room volume.

1. pollen and allergen cleaner
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The basis of this cleaner should be a HEPA filter that captures allergens in the environment. This filter reliably captures not only allergens, but also fine dust, viruses, and smog. The same quality results can be achieved by purchasing a filter that does not need to be replaced on a regular basis.

2. virus and bacteria purifiers .
Some of these purifiers utilize the principle of ultraviolet light. Ultraviolet light is an electromagnetic wave with a shorter wavelength than conventional visible light. When air contaminated from the external environment comes into contact with ultraviolet light, it destroys viruses, bacteria, and other microorganisms present. Germicidal effects can also be achieved through the use of antimicrobial filters containing silver nanoparticles.

3. air ionizer [20].
In other words, a negative ion generator that increases the efficiency of mechanical air cleaning. Ionizers work on the principle of promoting the precipitation and agglomeration of dust particles. Because of their ability to react with surrounding molecules, anions neutralize undesirable substances in the air. Ionizing air has many other benefits. It reduces stress and fatigue and has a positive effect on the respiratory system. A byproduct of ionization is the production of ozone. Ozone is beneficial only in small amounts, where it acts as a disinfectant.