When it comes to building automation, BACnet is the standard protocol used to integrate control systems from multiple vendors. It is an open standard that allows control system devices to talk to each other. CCN investigates the BACnet story.

Today, BACnet is the international standard of choice for HVAC applications. First developed by ASHRAE, BACnet has been under active development since June 1987, when the first meeting of standard project committee 135P took place at the ASHRAE annual meeting in Tennessee and the standard was first proposed.

It took eight-and-a-half years to complete, but in 1995 ANSI/ASHRAE Standard 135 was published and BACnet was officially born.

The following year the ASHRAE standing standard project committee 135 was formed to interpret, maintain and extend the standard.

In 2003, BACnet achieved the status of an International Organisation for Standardisation standard (ISO 16484-5).

Now it is no longer restricted to HVAC, and BACnet applications are used for a range of building systems covering lighting, fire and security.

BACnet is an ever-evolving communication standard that is constantly being expanded and improved with all the latest extensions and updates published on the BACnet International website at

The scope of BACnet has become vast. From its HVAC roots dating back more than 20 years ago to a widely accepted open protocol for building communications and integration, the scope of BACnet today is broadening all the time.

It has become even more valuable in the green age because it allows building managers to monitor and control building operational efficiency, which is central to energy efficiency.

The protocol provides meaningful performance data that facility executives can gather quickly, analyse and review to better understand the effect of building occupant behaviours and make better choices for energy management.

Because BACnet interoperability enables communication to subsystems and equipment such as variable frequency drives (VFD) or lighting panels, it can be used to manage fans, pumps and other devices to generate energy savings.

Meeting today’s green building criteria requires sophisticated building controls, and building automation is critical to sustainable design as building owners need to maintain a lot of data to get the full picture of a building’s operational performance. This information covers everything from temperatures to utility metering.

BACnet software provides a single-seat interface, which allows control of multiple building subsystems from one workstation. Interoperability is key as it also provides a single point of access for all of the major building systems, offering a more complete information set than would be available by accessing systems individually.

In addition to software enhancements, BACnet has also made a difference in the area of manufacturing.

For example, manufacturers of chillers and boilers now produce units that have BACnet integrated into the equipment, eliminating the need for hardwiring to the control device.
BACnet International is the international organisation that encourages the successful use of BACnet in building automation and control systems through interoperability testing, educational programs and promotional activities. BACnet International complements the work of other BACnet-related groups.

Its website features testing labs, case studies and all the latest product information. For example, one of the featured success stories is the Columbia Metropolitan Convention Centre in the state of South Carolina.

The three-level, 142,500 sq. ft. facility was designed to host meetings, conventions, trade shows, sports competitions, concerts and other events.

To meet HVAC requirements, engineering firm McCracken & Lopez developed a control strategy that addressed space temperature and humidity; CO2 levels; outside, return and supply air flow; duct static pressure; air purification; fire and smoke control and other operational issues.

The energy savings strategy addressed heat reclaim, morning warm-up, supply air temperature reset, kW demand temperature reset and more.

The company also devised monitoring and control criteria for the facility’s two 400-tonne Trane centrifugal chillers, two cooling towers and 13 pumps.

Harris Sales & Service was tasked with providing a control solution that could interface with multiple vendors and support monitoring, alarming and trending functions through one system.

The company chose WebCTRL, Automated Logic’s s building automation system. The installation features 2500 control points and 200 third-party points.