Field evaluation, in three commercial sites, of a small wall-mounted heat pump water heater. This follows an EPRI lab evaluation of the same product. This equipment is not currently available in voltages employed in the United States, and isn't UL Listed. Research questions: • Can these products meet U.S. residential and light commercial water heating needs, or are small modifications needed to provide competitive performance (e.g., larger resistance element)? • What are site-specific constraints that must be overcome? • How do hot water usage profiles vary (e.g., by time of day, by household occupancy, single family vs multi family, etc.) • How will occupants react to a more efficient water heater with less storage capacity and smaller electric element? Will performance be considered acceptable? • Are costs for a contractor-installed mixing valve of value in order to provide a higher level of storage energy to help meet hot water loads?