2. in what types of applications are WACS useful and cost-effective?

“It is hard to imagine an application where access via the Web would not be useful,” Bob Schultz, PE, director of applications services for TAC-Americas, said. While many respondents echoed that sentiment, several were more specific:

• Raymond Rae, vice president of marketing for Delta Controls Inc., said WACS “are most useful whenever remote or global access is required.” In particular, Gordon V.R. Holness, PE, president and CEO of Albert Kahn Associates Inc. and a member of HPAC Engineering’s Editorial Advisory Board, said, they are effective “where buildings have no resident maintenance personnel or where a complex of multiple buildings are geographically separated from their central maintenance service (i.e., an urban college campus).”
• In addition to “multi-site applications,” Ziejewski of Liebert said, Web-accessible controls are most useful for “’multi-user’ applications or where an ‘anytime-availability’ need is necessary.”
• Jeff Bredeson, group manager of product marketing for North America for Invensys Building Systems, said “thin-client solutions” such as WACS are most effective in an intranet environment in which the server or source is available to all other PCs on the network. “Connectivity can be offered outside of the private network to the Internet,” he said, “but this may require additional security precautions (i.e., proxy server/firewall) and registration of public IP (Internet protocol) addressing.”
• Kevin Osburn, vice president Apogee product marketing and development for Siemens Building Technologies, said the best use of Web-accessible controls is “primarily monitoring applications.”
• Kevin Duffy, vice president of sales and marketing for Notifact Corp., said wireless WACS are best used “where a BAS is not; on smaller facilities such as convenience stores, shops, (and) office parks; (in) mission-critical applications; (and in) remote facilities and unmanned facilities.”
• Paul Ehrlich, business-development leader for The Trane Company, said that typically, WACS technology “works best for viewing system data and changing setpoints and a few other basic operator functions.” However, “What this doesn’t work well for is storing large amounts of data, configuring a system, doing in-depth troubleshooting, and programming.”

As for cost-effectiveness, Tom of Automated Logic said, “There is no reason a WACS should cost more than a conventional control system.” A reason for this, Chief Engineer Mike Donlon and IT Strategist Rehan Kamal of Computrols Inc. said, is that: “Most buildings already support Internet service for other reasons. They have internal network wiring, firewalls, and an IT (information-technologies) staff.”

Rae said WACS “are most cost-effective on large sites with many users, where infrastructure already is installed.”

3. How do WACS impact construction scope, schedule, and budget?

The respondents were in agreement that WACS have virtually no effect on construction scope and schedule and--generally--only a minimal impact on construction budget.

“The Web enabling of the BAS is a minimal-cost item and fits into the schedule with the rest of the BAS implementation,” Nations of Johnson Controls said. “The only thing to consider is that it is planned into the implementation, not thrown in at the last minute.

A view of a chiller plant.
Image courtesy of Alerton Technology

“... If the WACS has software that resides on an IT server, and the IT department has space, it’s a no-cost issue,” Nations continued. “If the IT department says all departments provide their own server that must meet their minimum standards, there could be an impact, especially when their standards are high-end.”

Although a Web server likely will cost more than a single operator workstation (prices of Web servers start at under $1,000, according to Tom of Automated Logic), Ehrlich of Trane said, it may “be less expensive than buying and setting up three or four workstations.”

According to Rae of Delta Controls, time, manpower, and money can be saved during the commissioning process through the use of WAP- (wireless application protocol) enabled devices (Palm Pilots, Web-enabled cellular phones, etc.).

Although the project-management basics of WACS are virtually the same as those of conventional building-automation systems, it is important to note one possible exception: “The project-management team most likely will need to interface with the IT department for access to WANs and to make Web servers accessible to the outside world,” Haakenstad of Alerton Technologies said.

“This gets into the world of information and network security as well,” Haakenstad continued. “These same issues occur in any IP-enabled system regardless of whether it is Web-based or a typical client/server architecture that connects to a company’s WAN.”