Imagine working in a building where your office is how you like it, icy-cold, while your neighbour turns hers into a sauna.

If only your office lights and computer could flicker on every morning when you swiped your security card in your building’s lobby, so that you would be ready to work when you sat down with your first cup of coffee.

Buildings could do all these things and more, if only they had brains. 

A few buildings already do, and they’re getting even smarter. The brainiac of buildings, the United States Pentagon, opened for business on 12 September 2001, the day after terrorists crashed a plane into it.

Thanks to a network of digital sensors and controllers that let operators close dampers and turn off fans, the fire from the crash was confined to one wedge of the building.

The Pentagon’s costly, proprietary automation system isn’t likely to find its way into ordinary office buildings any time soon. But that doesn’t mean that we’ll be stuck with “dumb” buildings for the foreseeable future.

The good news is that two open communications standards for building automation are finally taking hold in the marketplace. One, known as BACnet (for Building Automation and Control Networks), has been endorsed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers.

The other, called LonWorks, was developed by Echelon Corporation (“Lon” stands for local operating network). These two standards have the best chance yet to turn the tide of the long, disappointing history of smart building control and automation.

In the meantime, technologies like those deployed in the Pentagon, along with some even more advanced, are being tested in government and university research labs.

Among other things, they’ll let future buildings minimise damage when an earthquake hits by automatically changing the way weight is carried by internal structures. Or upon detecting a harmful chemical substance in the building’s air ducts, the system would instantly seal them off and contact authorities.

For now, though, efforts to make buildings smarter are focusing on cutting costs by streamlining building operations like air conditioning and lighting.

Building automation is critical to these efforts, mainly because it could reduce the annual operating costs of buildings by a whopping 3.6 to 7 cents per square metre, according to a study conducted by the US National Institute of Standards and Technology.

Digital controllers

If building automation is such a fabulous boon, why hasn’t it caught on everywhere? Start by considering that the term building automation is a catchall for a sprawling category of control and communications technologies that link building systems that are typically controlled separately – like electrical distribution, fire, security, heating and air conditioning, and elevator and escalator systems.

To be effective, any automation system must enable all these mechanical and electrical systems to work from a single building control point.

That’s a tall order because those systems, and the digital controllers that run them, are made by scores of manufacturers, use proprietary hardware and communications protocols, and may even be administered through special workstations that are almost impossible to integrate into a single control setup.

BACnet and LonWorks take different approaches to integrating these diverse systems. BACnet, developed in the mid-1990s, is a communications-only standard developed for a building’s mechanical and electrical systems, particularly heating, ventilation, and air conditioning (HVAC). Companies that manufacture such systems are now beginning to make devices that “speak” BACnet rather than, or in addition to, proprietary control languages.

LonWorks, on the other hand, combines a communications standard, LonTalk, with a piece of hardware, the Neuron Chip from Echelon Corp. Born in the early 1990s, LonWorks has already caught on in the transportation and utilities industries and has been adapted for buildings; it is installed in more buildings worldwide than the BACnet standard.

Fortunately, the two are not mutually exclusive. BACnet can let Echelon’s Neuron Chips interact with building control devices made by other manufacturers.

Because the standard is compatible with the Internet protocol (IP), BACnet objects and devices can be viewed via standard Web browsers.

Interoperability issues

But as valuable as BACnet is in letting a building communicate to maintenance engineers and to the outside world, it also makes it possible for devices inside a building to talk to one another.

For example, when a smoke detector senses smoke, BACnet defines the way a signal from the smoke detector is relayed to a switch that would close off the dampers in a ventilation system, preventing smoke from spreading throughout a building.

Furthermore, BACnet allows users to set up to 16 levels of priority for command messages coming to, say, damper controllers from building automation software, such as energy management, fire safety, and comfort-level programs.

BACnet and LonWorks have come far in the last 10 years, but neither is yet in a position to end the long, stubborn history of proprietary turf battles in building automation.

Vendors of mechanical and electrical systems still make devices that communicate using their own idiosyncratic protocols. Even when systems are based on BACnet or LonWorks or both, manufacturers can still program devices to preclude free-flowing data exchange with other vendors’ equipment.

Hope for an ultimate resolution to interoperability problems might lie with that paragon of interoperability, the World Wide Web, which is transforming the interface of building control.

As more building owners demand remote access to building systems, manufacturers will have to make their systems accessible through Web browsers instead of proprietary workstations – something that BACnet and LonWorks already allow.

This is an edited version of an article that was first published by IEEE Spectrum, the world’s largest professional association for the advancement of technology. 

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