This book is a comprehensive source for technical information regarding ultraviolet germicidal irradiation (UVGI) and its application to air and surface disinfection and the control of pathogens and allergens. The primary focus is on airborne microbes and surface contamination applications. Water-based applications are not addressed here except incidentally as they relate to air and surface microbes, but adequate texts on water-based UV disinfection are available. All aspects of UVGI systems, including design methods, modeling, safety, installation, guidelines, and disinfection theory are addressed in sufficient detail that no additional texts need be consulted. Providing this information in one single source simplifies the design and installation of UVGI systems, help guarantee effective performance of new systems, and facilitate their use on a wide scale for the purpose of improving human health. This book is organized to provide systematic coverage of all related issues and will serve equally well as both a textbook and a handbook for general reference.