Building control systems are the dynamic or active part of the building that monitor, manage, and adjust the environment and performance of the building. There are a variety of control systems in buildings that support occupant comfort, a healthy environment, life safety, security, and the building’s basic infrastructure such as electric power and conveyance equipment. These control systems primarily address heating, cooling, ventilation, lighting, power, access to the building, shading, etc.
The basic control system monitors field devices and sensors that are connected to controllers or directly to a system headend. The data from the sensors and field devices are inputs to the control system. The data input is processed and compared to the rules and settings for the control system. Based on the input data, the control system will either determine the data is within an acceptable range and the system is operating properly or the data input is outside of an acceptable range triggering the control system to issue commands to change the status of the controlled device. A typical example would be the room temperature being higher or lower than the temperature setpoint. In this case the control system processes that data and commands or manages the equipment (in this case fans and dampers) to get the room temperature back to the setpoint.