The history and evolution of building control systems

The key to leveraging all these IoT smart building solutions lies in the ability of building owners and operators to unify their legacy building systems with new controls, sensors, and IoT devices for real-time, seamless access, management, and optimization. The evolution of smart buildings didn’t happen overnight; this has been slowly developing over many decades.

Prior to the 1970s, building management systems were local, with simple pneumatic controls. Pneumatics uses pressurized or compressed air that is distributed down a main line to control devices connected to that line. Air leaves through what is called a branch line and these branch lines act as a control signal to a device such as a thermostat and its controlled air damper actuator.

While pneumatics was still in heavy use in the 1980s, analog electric controls were introduced. These simple controls worked by turning a knob that injected resistance into a circuit. This resistance triggered the control device (valve, relay, etc.) to react. Electromechanical control systems were combined with pneumatic systems to control devices. The element would expand or contract on a thermostat that would open or close a circuit to turn the unit on or off. These systems were prone to calibration issues.

This was followed by the introduction and use of microprocessors, computers, and distributed digital process controllers in buildings in the 1990s, dubbing it the era of centralized controls. Direct digital control systems are still used today. Software programs were written allowing technicians and operators to control sequences by changing code. Controllers were daisy-chained together, creating a wired network. Building Automation Systems (BASs) and Building Management Systems (BMSs) were introduced. (We will review these systems in Chapter 2, Smart Building Operations and Controls.)

Fast-forward and the 2000s saw the intelligent buildings era, with the introduction of common in-building communication protocols such as BACnet and LonWorks. These protocols allowed individual devices to communicate with a central building system. Distributed digital computers were located on individual devices and communicated with the central system. Databases were created that facilitated analytics and the growth of energy management systems.

Over the last decade, intelligent buildings have transitioned to the smart buildings of today with central controllers communicating with powerful cloud-based software and AI-based machine learning applications that can optimize building designs, conserve energy, and predict equipment failures before they happen, demonstrating a vast improvement to building management overall. Unfortunately, in 2023, these systems are still disconnected, and sometimes proprietary, leading to multiple applications, silos of data, and user frustration.

I imagine that the next evolution of the smart building will be the unified building. A unified building fully connects and integrates all systems, components, sensors, and devices on a single platform to allow access and control and it will provide a unified view of the building on a single pane of glass. This will provide full integration of energy, facility, IT, security management, and control systems on a comprehensive, unified platform. Fully integrated and connected microprocessor-based controls and sensors will deliver massive amounts of data utilized for ML and AI applications.