This paper provides an overview of research related to automated fault detection and diagnosis for chillers, packaged air conditioners, and other vapor compression cooling equipment. The paper discusses the benefits, constraints, and possible products for FDD applied in the HVA C&R industry, presents results of fault surveys for packaged air conditioners and chillers, outlines the general structure and elements of an FDD system for HVAC&R equipment, describes specific methods associated with different FDD elements, and presents results from some specific case studies. The paper also attempts to provide an assessment of the state-of-the-art in FDD for vapor compression equipment and to identify the steps necessary to achieve widespread application.