The amazing abilities of an ultraviolet or UV light air purifier is undeniable, but is the same ultra-violet light technology also useful when it comes to purifying your ducts? UV light is a natural air purifier, capable of killing molds, yeasts and viruses. In addition, this natural purifier is available free because the sun emits it. However, as most people live indoors and not out in the sun, how can you use this naturally occurring air cleaner in your home.