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Last edited 02 May 2019
Building Automation and Control System BACS
The term 'Building Automation and Control System' (BACS) refers to centralised systems that monitor, control, and record the functions of building services systems. Building facilities that are monitored and controlled by a reliable BACS tend to maintain the building environment more efficiently and so reduce the building's environmental impact and energy costs.
The core functions of a BACS system are as follows:
- Maintain control of the building's environment.
- Operate systems according to occupancy and energy demand.
- Monitor and correct the performance of systems.
- Sound alerts as required.
The facilities that may be controlled by a BACS system include:
- Mechanical systems.
- Electrical systems.
- Heating, ventilation and air-conditioning (HVAC).
- Lighting control.
- Security and surveillance.
There is growing overlap between the concepts of BACS and the need to learn from the accumulated data to operate buildings more efficiently. Increasingly this includes technologies such as the internet of things to become smart buildings.
The basic components of a BACS are:
- Sensors: Measure values such as temperature, humidity, lighting levels, room occupancy, and so on.
- Controllers: Instigate the system's response from the collected data, using algorithms that apply logic and send commands.
- Output devices: Carry out commands from the controller.
- Communications protocol: The 'language' used by the BACS components.
- Dashboard: The user interface for data reporting and interaction with the BACS system.
There are a number of similar terms that can be used to refer to building automation, such as Building Management System (BMS), Building Control System (BCS) and Building Automation System (BAS). However, BACS is the standard term as defined by EN ISO 16484-2:2004 Building automation and control systems (BACS) -- Part 2: Hardware, 3.31.
BMS and BCS are general terms for systems that control a building's facilities. However, unlike BACS, they are not necessarily automation systems.
The phrase Building Energy Management Systems (BEMS) is sometimes used interchangeably with BACS, however, BEMS deal specifically with energy consumption, metering, and so on. It is generally considered though that there is sufficient overlap between the two that they can be used interchangeably.
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