Larger than necessary: You're probably oversizing expansion tanks in low-temperature systems

摘要

All closed-loop hydronic radiant heating systems require an expansion tank to accommodate the increased volume of the heated fluid. The usual sizing method for expansion tanks determines the volume of the system's fluid when the system is at it highest temperature relative to its volume when cold. The expansion tank volume is then calculated to accept the change in fluid volume without letting system pressure climb to the point that the pressure relief valve opens.