Abstract: An air conditioning system controlled for automatically heating and/or cooling a multiple zone building is disclosed wherein each zone includes a zone temperature responsive load transmitter. Each load transmitter produces an output command signal for controlling operation of damper units and heating and cooling equipment. The command signal configuration is modified to avoid operation of heating and cooling equipment throughout a relatively wide "no load" band of zone temperatures centered around the zone set point temperature. The command signal is highly responsive to sensed zone temperature changes beyond the no load band so that the zone temperature tends to be maintained in the no load band.An alternative system is disclosed in which no load bands occur at two distinct command signal values and operation of damper units is effected when the command signal value shifts between the no load band values.

Abstract: An air conditioning system controlled for automatically heating and/or cooling a multiple zone building is disclosed wherein each zone includes a zone temperature responsive load transmitter. Each load transmitter produces an output command signal for controlling operation of damper units and heating and cooling equipment. The command signal configuration is modified to avoid operation of heating and cooling equipment throughout a relatively wide "no load" band of zone temperatures centered around the zone set point temperature. The command signal is highly responsive to sensed zone temperature changes beyond the no load band so that the zone temperature tends to be maintained in the no load band.An alternative system is disclosed in which no load bands occur at two distinct command signal values and operation of damper units is effected when the command signal value shifts between the no load band values.

Abstract: A multiple zone air conditioning control system is disclosed in which air temperatures in respective individual zones are governed according to signals derived from sensed air temperatures in the respective zones and sensed temperature of air discharged to the respective zones.A zone set back unit is employed for setting back the air temperatures in all or any individual ones of the zones. The set back unit superimposes a set back signal on the temperature signals from the set back zones to effect a reduction of the air temperature in those zones as well as to prevent the sensed temperatures of air discharged to those zones from affecting the set back signal. The maintenance of air temperatures in zones which are not set back is unaffected by operation of the set back unit.