down-feed system[′dau̇n ‚fēd ‚sis·təm]
In a heating or cooling system, a piping arrangement in which the fluid is circulated through supply mains that are located above the levels of the units they serve.
1. A piping arrangement for a heating (or air-conditioning or refrigeration) system, in which the heating (or cooling) fluid is circulated through supply mains that are above the levels of the heating (or cooling) units they serve.
2. A water distribution system in which the water distribution main is located at the top of the pressure zone; the distribution-main supplies the risers that distributes water downward to the lowest point of the zone.