A zone control system is a series of dampers, which are installed throughout the ducts in the home. These dampers are like large valves, which can open and close to direct the flow of air through the house. The dampers split your home up into different zones, each of which can be conditioned without affecting the rest of the house. Each of these zones has its own thermostat installed inside it. When the thermostat detects a need for air conditioning, it opens the appropriate dampers and activates the system.