Evaluating Existing Hydronic Heating Circuits

This issue of idronics provides HVAC professionals with methods for evaluating the performance of existing hydronic heating systems. It begins with a discussion of different types of heat emitters and how their thermal performance varies with water temperature. It then presents relatively simple procedures for measuring temperatures and flow rates in existing hydronic circuits. It shows how to use those measurements to estimate the performance of the circuit over a range of operating conditions — such as at lower supply water temperatures. The latter serves as a starting point for evaluating the performance of those circuits with new heat sources. The issue concludes with a discussion of several design considerations when transitioning an existing distribution system to a new heat source.