When DNA is exposed to UV light, It's chemical bonding characteristics are altered so that cell reproduction no longer takes place - rendering the micro-organism harmless.
The ultraviolet region of the electromagnetic spectrum has a frequency just below visible light. Ultraviolet light is nature's way of controlling micro-organisms.Outdoors, germs are naturally regulated by ultraviolet light from the sun.
Ultraviolet light equipment produces ultraviolet light at the specific wavelength of 254mn (nanometers). At this wavelength the UV light is most effective at inactivation. As an airborne micro-organism passes through your heating and /or air conditioning system, the UV light penetrates the organism's membrane and alters its genetic material (DNA). With altered DNA, the micro-organism will no longer be able to reproduce, making it effectively harmless. Further, without the ability to reproduce, and due to the short lifespan of most micro-organisms, the population of them in the air diminishes rapidly and dramatically.
Information provided by ultravation light equipment specifications.
FINAL NOTES:In the past few years,as the popularity of Ultra-Violet lights has increased, information about these lights has been as varied as the air conditioning service and salesman's pitch. Here are a few things every home owner should know before having one of these installed on your system. In the case of UV lights, size does matter. The better units are going to have longer bulbs and are going to come in pairs. I always advise my clients to spend as much as they can afford on any IAQ product. One of the most important things to remember that a UV light does not clean an evaporator coil, blower motor or the interior of a Air Handler. A Ultra-Violet light will keep them clean. In other words everything inside that air handler needs to be cleaned before the light is installed in the air handler. I recommend to my clients that they get a unit that has two bulbs, one is placed on the return side just below the coil. The second bulb is placed on the supply side just after the evaporator coil and before the blower motor. Many customers have asked me, "If I have a UV light do I need a filter." The answer is an absolute yes. Again I tell my clients Buy the best filter system you can afford. I will write another bog soon about these filters. To recap: Buy a dual bulb UV light, buy the best one you can afford, have it installed after your A/C system is cleaned, better yet when a new one is installed. Bulbs should be replaced ever year. The better units will have a ten year warranty on the power head.
The Inspectors Corner
Jacob Mermin CHI/CMI
Jacob Mermin Inspections
www.mermininspections.com
Co-Founder Neighbor Helping Neighbor