Primary reduction

The Glitch:

A heating pro is asked to retrofit a pellet-fired boiler to an existing distribution system consisting of older cast iron radiators, iron piping and an oil-fired boiler. The system needs to draw heat from a thermal storage tank heated by the pellet-fired boiler, as well as an existing oil-fired boiler. The original heating distribution system was designed to use 180° F supply water on a design day, but will now be retrofitted by outdoor reset control. This will allow the distribution system to operate at supply water temperatures as low as 100° F on mild days. A portion of the proposed piping layout is shown below. Can you identify several details that could be improved?

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!