What Won't Prevent Mold Growth - UV Light           Ultra-Violet (UV) Light           Some companies sell ultra-violet lights to put in your furnace to prevent mold in your home. This is a waste of money. There is some evidence to suggest that light, even UV-light, may enhance mold growth1. Most mold spores are relatively unaffected by UV2. Ultra-Violet light units have a dosage of approximately 10,000 uw-sec/sqcm. It requires as much as ten times that energy to “kill” species of mold such as Aspergillius mold3. Even then, the resulting non-fertile spores are still floating around in the air and allergenic. Ultra-violet light does nothing to neutralize the allergens and toxins on the cell walls of mold spores.           UV light is effective in killing bacteria and viruses. When you see claims of UV light systems being effective, they are usually referring to how well they kill bacteria. There is not, however, sufficient evidence to show that bacteria are allergenic. Bacteria are present everywhere. They are part of the body’s natural micoflora. Pathogenic bacteria are not normally present in residential living spaces. Gram-negative bacteria, bacteria that can make you sick, may be present only when there is a source of water that causes mold growth. Bacteria may grow in water reservoirs such as humidifiers and steam generators with cellulose pads, in the air-conditioning pans if they get clogged up, and in general, where there is standing water.           If gram-negative bacteria are present, UV-light is not the answer. You must find and correct the source of water and mold, otherwise you will continue be exposed to toxins from bacteria called endotoxins. It’s not enough to just kill these bacteria because it’s not a disease that is causing the illness, but the toxins in the cell wall of the bacteria. Fragments of bacteria contain the toxins. When the cell walls of dead bacteria desiccate, fragments containing toxins become air-borne. These can be filtered out using a HEPA filter but correcting the source of the problem will usually make the problem go away.           The bottom line is that using UV light to treat the air in a residential living space on a regular basis is not necessary. The only practical application may be in air-conditioning systems when UV light is shown directly on the cooling coils of the air conditioning system. The cooling coils become damp from condensation during normal operation. UV-light is still not necessary if the air-conditioning drain pan is draining properly and there isn’t standing water. Don’t confuse this with the unnecessary installation of UV light system in duct work in general.               Back to top                            Copyright © 2014-2017 Healthy Living Spaces LLC.  All rights reserved.   877-992-9904 Revised: July 05, 2017. Information in this document is subject to change without notice. Other products and companies referred to herein are trademarks or registered trademarks of their respective companies or trademark holders.