Hello Phillip,
Yes, you should be able to model this within eQUEST using the basic loop controls. See the help information below for Valve-Reset. There are additional controls to adjust the loop temperature set-point as well.
Volume 2: Dictionary
HEAD-SETPT-CTRL
Takes a code-word that specifies the type of control sequence used for controlling the head set point of the loop circulation pumps.
FIXED The differential head pressure is controlled to a constant set point, specified as HEAD-SETPT. The location of the differential pressure sensor is HEAD-SENSOR-LOCN.
VALVE-RESET A fixed head set point is not used. Instead the pumps are controlled so that the system head is just enough to provide the required flow to the worst-case coil, with that coil's control valve fully open. In other words, this control sequence monitors the position of the control valves of all coils attached to this loop, and adjusts the head so that the worst-case coil valve is fully open. This minimizes the pump energy wasted through valve throttling. Normally, this control sequence will require a direct-digital control system.
Byron D. Burns, EIT, BEMP
Energy Engineer, Building Sciences Studio
H&A | Hankins & Anderson | www.ha-inc.com
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