UV, otherwise known as ultra violet light, is often used in water, food and air purification systems. The process of disinfection is called ultraviolet germicidal irradiation or UVGI and is the process by which short-length UV light (UV-C) is used to destroy nucleic acids and DNA of microorganisms, preventing them from surviving. In HVAC, this takes the form of Indoor Air Quality devices, which use UV bulbs. These bulbs can last 1 to 2 years before needing replaced. If you are interested in learning more about Indoor Air Quality devices, follow the link below.