Abstract: A climate control system having a control means for receiving cool call signals and heat call signals from a plurality of thermostats. The control means blocking action by conflicting calls when the system is in a heat mode or cool mode. The system also preventing a single zone from dominating the mode of the control system and allow a conflicting call to be received after the control system has been in a particular mode for a maximum period or the conflicting call has been waiting for longer than a maximum period. The control system also properly adjusting the dampers to allow purging of ducts after heating and cooling mode and to allow zone or system ventilation upon request.

Abstract: A zoned heating and cooling system is controlled by a relay panel with a controlling thermostat in a first zone, and an additional thermostat in each additional zone. A relay corresponding to each first and additional zone, a relay to control the mode in which the system operates, and a fan relay, work in conjunction with the thermostats to: turn on system heating or cooling equipment; open dampers to provide conditioned air to those zones which call for heating or cooling; close dampers to block conditioned air from entering the zones which do not call for heating or cooling, when other zones do call; open all dampers when there is no calling; and provide for the manual or automatic control of a system fan.