Ion generators are often used to remove small particles from the air, such as dust and allergens. They work by emitting negative ions that cause particles to stick to surfaces. However, ionizers are not powerful enough to produce a significant effect and can even generate harmful ozone and PM2.5, as well as cause particles to stick to surfaces in the house instead of eliminating them. Air purifiers with ionizers are commonly used nowadays to clean the air and remove allergens and dust.
Unlike HEPA air purifiers, air ionizers don't use fibers to trap contaminants and generally don't use filters. In response to the COVID-19 pandemic, people have been installing ionizers in offices and restaurants. When buying an air purifier with an ionizer, it is important to make sure that it is generating an ionization field and not a corona discharge. Ionization decreases dramatically with distance, so air ionization is rarely used for this purpose and only for elements immediately adjacent to the actual ionizer. Units that do not produce a crown-shaped discharge were never designed to sterilize the particles or air that circulate through the ionization section. Ionizers can be useful for removing small particles from the air, but they are not effective purifiers.
When buying an air purifier with an ionizer, make sure that it is generating an ionization field and not a corona discharge. Additionally, remember that units that do not produce a crown-shaped discharge were never designed to sterilize the particles or air that circulate through the ionization section.