What’s the Story with UV Light and Safety?


Ultraviolet (UV) lights have been lifted to the public consciousness recently with the rise of COVID-19 and the novel coronavirus.

While there is much speculation and misinformation about the effectiveness of UV lights, Temp Control wants to deliver the straight facts and inform you of some possible options for utilizing UV light safely and effectively to improve indoor air quality (IAQ).


First, UV light is never recommended to be used directly on humans. UV light should only be used on objects and surfaces as a disinfectant. Ultraviolet light, particularly UV-C–has been demonstrated to destroy other coronaviruses and bacteria, so it may work on the novel coronavirus. UV light of any kind, however, can damage the skin and eyes. Long-term exposure can cause cancer.

For HVAC purposes, though, UV light can be a useful tool in improving air quality and helping maintain the HVAC system. UV-C lights eliminate mold and other contaminants that can recirculate in a forced-air system. Plus, UV-C lights help deter the growth of fungi which can grow on air filters, coils, and ductwork. These pollutants can recirculate and build up on the coils making the unit work harder—costing money and wearing down the components; plus, the contaminants that are not trapped by an air filter will continue to circulate through the home.


Ultraviolet light can generally be applied two ways in a home’s HVAC system. The most common way is to install a UV-C light near the indoor coils of the air handler. The light will kill most of the bacteria, fungi, and other microbes that collect on the surfaces there where moisture gathers and creates an ideal growth environment. The light—a single bulb or a dual bulb—is installed where the light continually shines directly on the coil whether the unit is running or not.

The other kind of HVAC UV light sanitizer is installed in the ductwork. This is sometimes referred to as “air sterilization.” This light treats the air flowing to the system. It kills airborne contaminants that flow past the light. This kind of system can be triggered to run only when the fan is blowing, thereby saving some energy cost and saving the life of the bulb.

Either method is an effective way to improve the indoor air quality of your home and may also save a little maintenance on the coils, filter, and the rest of the HVAC system. For allergy sufferers and people with respiratory illness, this kind of air treatment can go a long way for personal safety and comfort. Installation for this kind of treatment can be tricky. We recommend you do not attempt this sort of installation on your own. Rather, trust the professionals at Temp Control to evaluate your home, your current system, and then allow us to make a recommendation that fits your budget and your needs.