Air purifiers have a formidable efficiency against pollens, mites, odors and particles thanks to different levels of filtration. Air purifiers frequently have a pre-filter to retain large dust and animal hair, a HEPA filter of medical quality against fine particles, a photocatalytic filter coupled with a retaining UV lamp and a charcoal filter against odors. The purifier filters the indoor air and purifies it by eliminating the different sources of pollution, and the purification of the air goes through several stages.
To work well your air purifier and your best portable ac unit must be running continuously and not disturb you during your day. It is impossible to say that purifiers transform our interiors into healthy bubbles, without any more pollutants, and no manufacturer commits itself to that. Most manufacturers commit to an efficiency superior to 99% on pollen and allergens.
Therefore, are these devices necessary? There are many origins of indoor pollution and some particles are more dangerous than others. The smallest particles enter the body, lodge in the lungs and in the blood. As for other particles, such as pollen and allergens, they are not considered dangerous, but they still deserve to be filtered.