Patent ID: 7819331

Claim:
A controller configured to control an HVAC system having a plurality of zones and having a multiple stage fluid temperature conditioning device, the controller comprising: (i) a plurality of thermostat terminals for receiving a plurality of thermostat signals from a plurality of thermostats, each thermostat located within one of a plurality of zones, where each one of the plurality of thermostat signals indicates a call for conditioning in the zone where that thermostat is located; (ii) a plurality of flow control terminals, each flow control terminal configured to transmit a signal to control one of a plurality of flow control devices in response to a call for conditioning in one of the plurality of zones; (iii) one or more timers connected to the thermostat terminals, the one or more timers configured to initiate a separate timing count upon each call for conditioning in any one of the plurality of zones; and (iv) one or more staging terminals for transmitting staging signals to control a multiple stage fluid temperature conditioning device, wherein the transmission of the staging signals determines whether the conditioning device will operate at a lower output stage or a higher output stage; (v) wherein the controller is configured to make a timing count determination to determine if any one of the separate timing counts initiated upon each call for conditioning in any one of the plurality of zones exceeds a timing delay parameter; (vi) wherein the transmission of staging signals depends on the timing count determination.