FCU Cooling Source

1 post / 0 new


I have dedicated individual FCU's at several zones. Each FCU is to be
connected to a CHW and HW loop which comes from a campus central plant. The
intention was to have the FCU directly feed the conditioned air to the zone
w/ no terminal unit; only a thermostat and meter would be included as the
"zone features" components.

Question: Why does eQUEST not allow me to specify "Chilled Water" as the
"Cooling Source" for the FCU's? Instead it forces a zone terminal to be
connected to a CHW and HW loop (which I do not want). Any thoughts?

Also, when comparing my baseline (FCU system as described above) model to
the design case (AHU connected to VAV's w/ reheat) the CHW load is larger
for the FCU system (2727 hours compared to 1750 for design-case) but the CHW
energy use is lower in the baseline scenario (72Mmbtu vs. 120). This seems
counter intuitive. What might cause this?

Your time and feedback are always appreciated.

Robert Des Rosiers, LEED-AP

Robert Des Rosiers's picture
Joined: 2011-09-30
Reputation: 0