18 August 1998
Cooling and heating operation.
Cooling and heating start/stop schedules.
Cooling and heating occupancy schedules.
OA dry bulb temperature.
Program outputs. Automatic or open/close override damper control signal.
c. Application notes. This program operates in conjunction with scheduled start/stop and optimum
start/stop programs prior to building occupancy.
6. HOT DECK-COLD DECK TEMPERATURE RESET PROGRAM. The hot deck-cold deck
temperature reset program is applied to dual duct systems and multizone HVAC systems. These
systems utilize a parallel arrangement of heating and cooling surfaces, commonly referred to as hot and
cold decks, for providing heating and cooling capabilities simultaneously. The hot and cold air streams
are combined in mixing boxes or plenums to satisfy the individual space temperature requirements. In
the absence of optimization controls, these systems mix the two air streams to produce the desired
temperature. When the space temperature is acceptable, a greater difference between the temperatures
of the hot and cold decks results in inefficient system operation. This program selects the areas with the
greatest heating and cooling requirements, and establishes the minimum hot and cold deck temperature
differentials which will meet the requirements, thus maximizing system efficiency. Zone space
temperature sensors are used to determine the greatest cooling and heating space temperature
requirements during the building occupied period and reset the corresponding deck temperature
proportionately. Where humidity control is required, the program will prevent the cold deck cooling coil
discharge temperature from increasing further when the maximum allowable space humidity setpoint is
reached. 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.
Hot deck heating coil discharge temperature.
Cold deck cooling coil discharge temperature.
Space dry bulb temperature - one sensor per zone.
Space relative humidity - one per zone of humidity control.
Mixing box damper position or proportional control signal feedback - one per zone.
UMCS outputs to utility system.
(a) Hot deck heating coil control valve proportional control signal (for direct digital control
Hot deck heating coil control valve CPA (for supervisory control implementation).