Reverse Cycle Chiller Distributed Heat Loss

This project proposes to research an issue which was identified during the current reverse cycle chiller (RCC) study regarding distributed heat loss. This project builds on an existing BPA funded multifamily heat pump reverse cycle chiller project, TIP 140. The results of this project have been good. This is a technology which has potential for multifamily and other applications in the Pacific Northwest. The TIP 140 project results identified that hot water recirculation systems can reduce efficiency by 30-40%. Additional work needs to be done to quantify the energy losses associated with typical hot water distribution systems. This research project contains a comprehensive approach to understanding and reducing energy losses in hot water recirculation systems. There are three work areas. The primary area is a pilot study to set up three different hot water distribution systems and understand the impact these three different approaches will have on the overall system efficiency. The second area is to meter actual heat loss from recirculation systems in two to three existing midrise multifamily buildings to better characterize the baseline. The third area is to directly measure performance of inverter-driven heat pump water heaters in the field with and without the impact of recirculation loops.