A zone control system is integrated into the ventilation system that connects to a forced–air heater and air conditioner. The components consist of a set of dampers that can close off airflow to specific parts of the ventilation network. Installers fit the dampers into the ducts, putting in as many as are necessary to create the number of "zones" in a home. (For example, one very simple configuration is to have one zone for the upstairs and one for the downstairs; but there could also be as many zones as there are rooms.) The dampers connect, usually wirelessly, to zone thermostats that can manipulate them independently of the others. In turn, all the dampers connect to a central control panel that permits a homeowner to change the damper settings throughout the rooms.