UV air purifier for air cleaning and disinfection

An ultraviolet or UV air purifier uses a special property of ultraviolet light to kill bacteria, viruses, mold, fungi, as well as to clean your air from harmful organic pollutants, such as dust mite feces, hair and dander dust particles, and volatile organic compounds.

The reason UV light works for air purification is its ability to induce destructive chemical reactions (photochemistry) in the indoor air pollutants. In addition to air purification via direct chemical action, a UV air purifier also has a strong indirect air cleaning action. In particular, it can convert molecules of oxygen and water in your air into ozone and hydroxyl (OH) and hydrogen peroxide. Those active molecules then react with air pollutants, destroying and decomposing them into harmless components, such as water and carbon dioxide.

While ozone is a harmful pollutants itself, it is not necessary for effective air cleaning in an UV air purifier, and it can and should be avoided. Hydroxyl molecules are a better alternative. While still cleaning the air, they do not have any harmful effects of ozone. Fortunately, hydroxyl and ozone are produced by different wave length components (different parts of the ultraviolet spectrum) of the UV light.

A good uv air purifier has such a UV spectrum that it minimizes or eliminates ozone formation (very low intensity at 185 nm ozone-producing wave length), while having high intensity at around 254 nm wavelength, which stimulates hydroxyl production for effective air cleaning.

The effectiveness of an ultraviolet air purifier depends on the intensity (wattage) of the UV light and the time of exposure to the light. So, you typically need quite a high wattage UV lamp, especially in case of fast air flow.

A UV air purifier does not need any replacement filters (filterless technology), unless it is combined with air filter parts. Yet, you may need to pay attention to the UV lamp. It loses its intensity every year of operation (like 15 percent per year), and should be replaced time after time (depends on the UV lamp quality.)

HEPA air cleaner as an alternative to UV air purifier
HEPA air cleaner basics. What a HEPA media air purifier does and where it can help.