18 August 1998
(c) Cold deck cooling coil control valve proportional control signal (for direct digital control
Cold deck cooling coil control valve CPA (for supervisory control implementation).
b. Software I/O requirements. The software requirements are:
Zone space temperature set point.
Zone space temperatures.
Space humidity set point (where shown).
Space relative humidities (where shown).
Mixing box damper position or proportional control signal feedback.
Hot deck temperature.
Cold deck temperature.
Minimum space temperature during occupied periods.
Maximum space temperature during occupied periods.
Hot deck temperature setpoint.
Cold deck temperature setpoint.
c. Application notes. This program operates in conjunction with the chilled water temperature reset
7. REHEAT COIL RESET PROGRAM. Terminal reheat systems operate with a constant cold deck
cooling coil discharge temperature. Air supplied at temperatures below the individual space temperature
requirements is elevated in temperature by reheat coils in response to signals from individual space
thermostats. The program then resets the cold deck discharge temperature upward until it equals the
discharge temperature of the reheat coil with the lowest demand. Where humidity control is required, the
program will prevent the cooling coil discharge temperature from increasing further when the maximum
allowable space humidity setpoint is reached. For air conditioning systems, where reheat coils are not
used, the program will reset the cold deck discharge temperature upward until the zone or space with the
greatest cooling requirement is satisfied. Design requirements for this applications program will be
indicated by the letter X adjacent to the program listing on the appropriate database table, as shown in
Chapters 8 and 9.
a. Field hardware requirements. The hardware requirements are:
UMCS inputs from utility system.
Cold deck cooling coil discharge temperature.
Reheat coil valve position or proportional control signal feedback - one per reheat coil