Page 17 - Climate Control News Oct 2021

Building Automation
damage when an earthquake hits by automati- cally changing the way weight is carried by inter- nal 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 stream- lining building operations like air conditioning and lighting.
Building automation is critical to these efforts, mainly because it could reduce the annual oper- ating 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 Stand- ards and Technology.
DIGITAL CONTROLLERS
If building automation is such a fabulous boon, why hasn’t it caught on everywhere? Start by consider- ing that the term building automation is a catchall for a sprawling category of control and communi- cations technologies that link building systems that are typically controlled separately – like elec- trical distribution, fire, security, heating and air conditioning, and elevator and escalator systems. To be effective, any automation system must ena- ble 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 work- stations that are almost impossible to integrate into a single control setup.
BACnet and LonWorks take different ap- proaches to integrating these diverse systems.
BACnet, developed in the mid-1990s, is a com- munications-only standard developed for a building’s mechanical and electrical systems, particularly heating, ventilation, and air condi- tioning (HVAC). Companies that manufacture such systems are now beginning to make devic- es that “speak” BACnet rather than, or in addi- tion to, proprietary control languages.
“IT IS TIME TO END THE PROPRIETARY TURF BATTLES IN BUILDING AUTOMATION.”
LonWorks, on the other hand, combines a communications standard, LonTalk, with a piece of hardware, the Neuron Chip from Eche- lon Corp. Born in the early 1990s, LonWorks has already caught on in the transportation and util- ities industries and has been adapted for build- ings; it is installed in more buildings worldwide than the BACnet standard.
Fortunately, the two are not mutually exclu- sive. BACnet can let Echelon’s Neuron Chips in- teract with building control devices made by other manufacturers.
Because the standard is compatible with the Internet protocol (IP), BACnet objects and devic- es 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 de-
vices 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 com- ing to, say, damper controllers from building au- tomation 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, man- ufacturers can still program devices to preclude free-flowing data exchange with other vendors’ equipment.
Hope for an ultimate resolution to interopera- bility problems might lie with that paragon of in- teroperability, the World Wide Web, which is transforming the interface of building control.
As more building owners demand remote ac- cess to building systems, manufacturers will have to make their systems accessible through Web browsers instead of proprietary worksta- tions – 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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CLIMATE CONTROL NEWS OCTOBER 2021
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