TEC Zoning Control System for Stand-Alone and BACnet® MS/TP ...

PIR Onboard Occupancy Sensor (TEC2647Z-2+PIR Model)The PIR onboard occupancy sensor allows for automatic switching between fullyadjustable occupied and standby temperature setpoints without user interaction.This feature results in incremental energy savings during scheduled occupiedperiods when the space is not being used.Demand-Based Heating and Cooling SystemThe system operation determines which zone controllers have heating and coolingweighted votes used by the associated rooftop controller. The rooftop controlleruses the weighted heating and cooling demand values from selected zones todetermine if heating or cooling action is required for the system.Internal and external zones are typically serviced from the same rooftop controller.As a result, the system may be exposed to conflicting mid-season heating andcooling demands. The conflicting demands are addressed with the heating andcooling lockouts, based on the outside air temperature at the rooftop controller.The heating or cooling action at the zone depends on how the rooftop controllertreats and calculates what is delivered to the zones. Many factors influence thedelivery and availability of hot or cold air to satisfy the current zone demand.Table 3 through Table 5 shows the rooftop controller system mode calculationbased on the highest demand of the zones, the average of the three highestdemands, or the average of the five highest demands.22TEC Zoning Control System for Stand-Alone and BACnet® MS/TP Networked ApplicationsTechnical Bulletin