Caleffi’s 9th edition of idronics, “Geo-Hydronic Systems,” explains the basics of heat pump operation and describes several types of heat pumps. The discussion then turns to the use of modern hydronics to enhance the efficiency and comfort provided by these pumps. Other discussion topics include system configurations ranging from simple single-zone/heating-only systems to large multi-heat pump heating and cooling systems. Also provided is specific information on sizing components such as buffer tanks, expansion tanks and circulators.