This UV system is installed to kill the bacteria that are developed in the storage tank (if any). An ultra-violet purifier unit contains one or more germicidal ultraviolet lamps. This lamp produces ultraviolet wavelengths that are lethal to microorganisms. Approximately 95% of the ultraviolet energy emitted is at the mercury resonance line of 254 nanometers. This wavelength is in the region of maximum germicidal effectiveness and is highly lethal to virus, bacteria and mold spores. Therefore, in UV system, the water or air that passes through the chamber is exposed to the germicidal UV light and the genetic material of the microorganism is deactivated, which prevents them form reproducing and renders them harmless.