Under-umphed

The Glitch:

An installer pipes up the system shown in Figure 1. Its purpose is to provide two zones of space heating. The heat emitters are fan-coils with relatively high pressure drop characteristic. The system also provided domestic hot water using an indirect tank. The boiler loop is intended to keep the boiler operating above the dewpoint of the flue gases and protect it from thermal shock. Can you identify some problems that are likely with this set up, and propose an alternative design to eliminate any such problems?

Are you an ace troubleshooter?

Within the pages of this magazine, PM’s Hydronics Editor John Siegenthaler, P.E., will pose a question to you, our readers, to review a system’s schematic layout and discover its faults, flaws and defects. Discover archived “The Glitch & The Fix” exercises at its radiant-focused website, www.radiantandhydronics.com. Good luck!