This is how air purifiers work
HEPA filtration is rapidly coming into many medical applications such as isolation of patients under treatment involving immunological isolation, care for burn victims, orthopedic surgery, etc.
Ionic Air Purifier Information: Ionic air purifiers contain negative ion generators that charge airborne particles so they become attracted to and settle on room surfaces, effectively removing harmful particles from the air you breathe. However, room activity may stir up and release the particles back into the air. For this reason many ionic air cleaners contain electrostatic precipitators which trap particles on oppositely charged metal plates. The plates need to be cleaned periodically for optimal performance.
Ultraviolet Air Purifier Information (UV): Ultraviolet light is one of the more effective methods to reduce and control airborne pathogens. For this reason ultraviolet purifiers are commonly used in hospitals. As contaminated air is passed through intense ultraviolet light, bacteria, viruses and some organic compounds are destroyed. In short, the ultraviolet light damages the DNA of microorganisms and renders them harmless and unable to reproduce. Ultraviolet light is used in much the same way for water purification systems. Because viruses are too small to be trapped by HEPA filters, ultraviolet light is one of the only ways to eliminate airborne viruses.
Ozone Air Purifier Information: Ozone is popularly known for its ability to filter ultraviolet light in the upper atmosphere. Ozone in the lower atmosphere can be used to reduce airborne contaminants. The basic oxygen molecule in the air we breathe is composed of two oxygen atoms. Ozone is composed of three oxygen atoms. Ozone's extra oxygen atom can become detached from the ozone molecule and reattach to molecules of other substances, altering their chemical makeup and often leaving only carbon-dioxide, oxygen and water. This is the basis for ozone air purifiers. Ozone air purifiers release an ozone enriched gaseous plasma into the air that seeks out airborne contaminants. This purification method does not draw the surrounding air into a central filter, allowing for large areas to be purified efficiently.
Activated Carbon Information: Activated carbon filters behave as sponges and trap most airborne gases and odors. Activated carbon is charcoal that has been treated with oxygen to open millions of small pores between the carbon atoms. These pores adsorb harmful gases and odors. Due to the large surface area of the carbon granules, carbon filters are excellent at trapping gases that pass through traditional particle filters. However, as the pores become filled with trapped contaminants the filters loose effectiveness and will need to be replaced.