Optimizing water-loop heat pump design and performance

Water-loop heat pump (WLHP) systems for space conditioning of buildings have an intrinsic capability to save energy by transferring or balancing heat from building areas requiring cooling (typically, the core) to areas requiring heating at the same time Z (for example, perimeter zones). This paper reports that other advantages include relatively low cost, modularity for zoning and incremental add-on, local control, and ease of integrating thermal storage for load management. These features make WLHP systems attractive for many commercial and public buildings, and they have been used for a number of years. However, relatively little data have been available for systematically assessing and optimizing the performance of complete, installed systems. To help meet this need, a comprehensive field test project to study the operating characteristics of a representative WLHP system has been conducted for over three years in a typical commercial office building in Stamford, Connecticut. The site climate includes cold winters, warm to hot summers, and substantial shoulder seasons, so that results pertinent to a variety of weather conditions have been obtained.