By BEATRICE WITZGALL and ANDY MCMILLAN
BACnet has been a core element of the building automation business for years, yet many lighting professionals are unaware of exactly what it is. BACnet is a universal communication protocol for Building Automation and Controls that unifies various systems and vendors into one network and control interface. The globally accepted standard allows intelligent devices in buildings to interconnect and interoperate by defining communications rules and networked equipment mechanisms to exchange data, commands, and status information.
The key to making a building successfully “smart” is the interoperability of discrete systems and equipment supplied by numerous vendors. Integration across multiple systems and vendor solutions through an open standard achieves cost savings and streamlined operations for building owners. It also provides flexibility for future use cases. BACnet is the link that connects multiple systems, enabling sophisticated energy management, occupant comfort, and building security applications.
BACnet also enables information and controls from all building systems to be combined into one single graphical control interface, which can also be accessed remotely. It simplifies operations, reduces user training, streamlines maintenance, provides alerts, and allows room for expansion and cross-functional add-ons. That is why BACnet has grown to become the predominant worldwide building integration protocol. According to a 2018 market study, BACnet is being specified in nearly 65% of projects globally and in over 80% of US projects.
The smart building is a large, interconnected puzzle where each component is a piece of a much bigger picture. A smart building shares data across multiple systems to respond to real-time needs and conditions or to learn and optimize building operations. When the building automatically knows how to react to the data and changes in its external environment, all within the parameters of its design intent and equipment requirements, it then becomes smart.
Building automation and its associated technologies are gaining more relevance and momentum, especially during the current coronavirus pandemic. It is an evolving landscape with new requirements and applications under constant development. Although individual equipment technology is often in place, if the correct infrastructure has not been set up, enabling various systems to communicate with each other becomes complicated and expensive.
BACnet addresses integration of all aspects of building systems including HVAC (heating, ventilation, and air conditioning), security, shade controls, fire detection, sprinkler systems, energy and air quality monitoring, access controls, power distribution, and lighting. All these systems can operate and work independently, but they become unified and provide new value propositions with BACnet as the network’s protocol backbone.
Use cases
The use cases are extensive, and it is up to the building owner and the designers to define them. One office use case could be automatic dimming of conference room lights when a meeting is scheduled to end as a means to signal occupants to wrap up. Another scenario could entail the HVAC system adjusting to occupants’ actual locations within the space rather than having the entire space heated or cooled to a certain temperature despite vacancy.
Initial use cases of building system connectivity revolved around energy savings to cut building operational costs, such as connecting access systems with occupancy to turn lights off when no one is in the space. Another functional use case is load shedding to take advantage of utility rebate programs through power-utility credits.
Getting employees safely back to work during the pandemic opens up the possibility of new use cases. For example, how can you manage density reduction if you cannot measure real-time occupancy? Or how can you ensure a clean workstation when you do not know where someone has been sitting?
Some of these scenarios can be managed internally with a standalone lighting system via sensors, but others require integration across systems or vendors. For example, a more advanced use case is wayfinding, where an employee enters the office by swiping their access keycard and the hallway lights turn on all the way to the employee’s assigned office. Automated notifications to maintenance workers when lights fail or are about to reach end-of-life are other common use cases.
Unfortunately, many lighting controls manufacturers focus on their ecosystem and an isolated silo of hardware and software with little consideration of its integration into the larger ecosystem. As a result, they do not offer or embrace integration with BACnet. It frequently requires a special request by the building owner/operator early in the specification process.
Typically, lighting controls are self-sufficient proprietary systems with limited open interfaces or application programming interfaces (APIs). While HVAC and other applications have adopted and integrated BACnet natively, the lighting industry has not. This limits potential applications for building owners and increases costs when the network control technology is not addressed and specified early enough.
Building owners/operators need to understand that identifying the overall integration needs and protocol early in the process is crucial. They also need to define relevant use cases so the technical requirements can be outlined and established to specify which systems need to communicate and in what ways.
