Web-accessible controls systems (WACS) were the cool and captivating draw in the building-automation section of the 2001 International Air-Conditioning, Heating, Refrigerating Exposition (AHR Expo 2001) in Atlanta. The booths that had them available for display and demonstration were jammed.

The concentration of vendors and their demonstrations amounted to an electrifying short course in the integration of Web and building-systems technologies. HPAC Engineering took a look at many of the products and discussed their features with manufacturers’ experts staffing the booths. We were impressed by the simplicity with which WACS provide flexible, simple access to building-automation systems (BAS) and equipment-mounted controls from locations inside and outside of buildings. We were delighted to see that this technology has progressed to the point where cell phones and pagers, which now are standard equipment for owner-engineers, have become an integral part of alarming and alarm response.

The demonstrations inspired us to compose a list of 20 questions about WACS that designers and owner-engineers might ask. We have spoken with many of these individuals in the past and have a pretty good feel for what their concerns are. Some of their concerns likely are rooted in computer phobia, an inherent distrust of manufacturers’ claims of “simplicity” and “cost-effectiveness,” and/or a lack of understanding of the information technologies that are key to implementing WACS. Some concerns, however, are diplomas from the School of Hard and Expensive Knocks, earned from buying into new technologies too early.

The questions were sent not only to AHR Expo 2001 exhibitors, but to manufacturers who were not at the show. They also were sent to designers and owner-engineers to gauge their impressions and knowledge about WACS. The responses yielded a fascinating snapshot of an emerging technology that is simplifying a new and complex world of jargon and hyperbole while also paving the way for the Net-generation workers nipping on the heels of the current work force. This article is a frank but friendly discussion of the features and capabilities of WACS, as well as the challenges to which manufacturers will have to rise if they are to win the hearts, minds, and dollars of their customers.

1. What capabilities do WACS offer that conventional automation systems do not?

WACS provide full accessibility to building-automation systems through an ordinary browser, such as Internet Explorer or Netscape Navigator, without proprietary software being loaded onto every computer that is used to access the system.

“A WACS requires a single Web-server computer on site that runs software from the building-automation vendor,” Larry Haakenstad, director of sales for Alerton Technologies Inc., said. “But for access via a LAN (local-area network), WAN (wide-area network), or even remote dial-up, the user is able to simply use the standard Web browser already on the computer.”

“This,” according to Steve Tom, director of technical information for Automated Logic Corp., “effectively means that any computer on the network can be a building-automation workstation. And if the WACS is linked to the World Wide Web, it means that the user can access the system from virtually any computer in the world.”

Such ease of information access has led to a “paradigm shift” in the application of building-automation systems, Brady Nations, manager of business development for Johnson Controls Inc., said.

“Now it is possible to provide information to the ‘customers’ of the facilities staff, the occupants of the facility who may benefit from interaction with the BAS, but haven’t been able to do so in the past because it was cost- or technically prohibitive to do so,” Nations said. “Consider the scientist who has environmentally sensitive experiments going on in the lab. He might like to know at any given time, from any given place, what the current conditions in his lab are. The BAS has access to that information and can deliver it to the scientist at his home, his office, or any place he has access to a Web-connected appliance.”

“Just as possible,” Haakenstad said, “a tenant could monitor his or her own space.”

Another advantage of WACS is that they provide a higher degree of interoperability than do conventional automation systems, a benefit that is greatly increased in the presence of an open protocol, Tom said.

“The Internet itself is based on open protocols,” Tom explained, “and standards such as HTML and TCP/IP provide an open conduit for interoperability. At the very least, a user should be able to access two different vendors” WACS from the same Web browser. With only a slight effort and a skill set taught at most high schools, a user can create Web pages that combine data from multiple WACS into a single summary page. There should be no need to create custom Web pages, though, as WACS that utilize BACnet or other standard protocols can integrate data and control parameters from multiple vendors” equipment into a single user interface. If the WACS itself utilizes Internet standards such as Java and ODBC, the system is even more interoperable and is not tied to a single hardware platform.”

Also compared with conventional automation systems, WACS offer “better integration (with) existing-building wiring, which, in turn, allows for easier installs and lower costs,” Steve Ziejewski, a product manager for the Liebert Monitoring Group, said.

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