Building the Control Station

When local or central computers are used for controlling the operation of HVAC installations in buildings, they are described as building automation systems. In the control station, operators communicate with control instal­lations, which are connected through the computer plant. Computers for individual use are called personal computers (PCs). The use of PCs for technical and economic tasks in the past few years has increased consider­ably. The business overflows with PCs, which get greater data power and memory at lower prices.

Building control systems are typically classified as

• Local instrumentation (control system)

• Data-based local controllers

• Control station with computers, mainframe or PC

Because of these solutions, important technical data can be transferred from local instrumentation (control system) through data-based controllers to a control station with computers. The operator may use the many varia­tions that the software data system provides. Technical data operation may be digital off/on messages such as the status of operation and the perfor­mance of alarms or analog measurements such as temperature, humidity, pressure, velocity, energy usage, etc.

From the operator’s PC in the control station, the operator should be able to perform the following operations:

• Switch on and off electrical lights.

• Control the heating and ventilating systems.

• Switch on and off and control the speed of pump and fan motors.

• Control valves and dampers.

• Detect the condition of and operate filters and dust-cleaning devices.

• Receive and register status and alarm messages.

• Read measured values (temperature, energy, etc.).

• Change set-point for regulation.

• Receive and register energy information, and record the trend log.

• Control and regulate the power consumption.