BAS at the Crossroads
Depending on one's affinity for technology, an ideal habitat might be described as follows: Its processes and the needs of its occupants are monitored, assessed and evaluated continuously. Decisions for maintaining the most desirable environment for this habitat are made with a holistic and global approach where numerous possible actions and responses are quickly factored before the best choic...
Depending on one’s affinity for technology, an ideal habitat might be described as follows: Its processes and the needs of its occupants are monitored, assessed and evaluated continuously. Decisions for maintaining the most desirable environment for this habitat are made with a holistic and global approach where numerous possible actions and responses are quickly factored before the best choice is made. All aspects of comfort, cost, security, life safety, maintenance and environmental impact are optimized at every moment. The habitat’s capabilities and its needs are well matched by an open communication of the information between all its members. The systems monitoring and controlling this environment are not closed and are supervised and updated by a dynamic world of external resources to maintain, diagnose and correct software and provide instructions for the environment’s repair, maintenance and improvement.
Sounds like the abstract some TV executive pitched in the 1960s for the “Jetsons” or “Star Trek,” right? While it certainly sounds futuristic, such habitats exist in the cars we drive, and in some cases, the homes in which we live. New York Times technology writer Paul Boutin recently wrote on this subject, describing a computer-controlled microwave/refrigerator that allows its owner to pop a chicken into the machine before going to bed. The device automatically chills the bird overnight, warms it to room temperature the next afternoon, then calls the would-be chicken consumer’s cell phone with a text message querying if it should begin cooking.
Obviously, homes and cars are but a child to the greater habitat of most commercial/institutional/industrial buildings. But what needs to happen today so that our offices and factories can enjoy the same level of performance found in new cars and homes?
Driving toward change
Of course, there is a major difference between buildings and cars. We need to identify the differences in applied technologies in these two habitats. Cost, complexity, size, life span, mobility and diversity in function are just a few. These issues can explain the time lag between technology implementation at the same level as in the automobile industry and buildings. At the same time, it is this researcher’s opinion that the automobile industry has been the laboratory for developing, testing and implementing technology that will eventually revolutionize building automation technology.
But before going there, a brief examination of the state of the building automation industry is necessary. Commercial building automation systems (BAS) today can offer electronic controls that integrate a variety of building systems such as HVAC, lighting, security, fire-alarm and process controls into a central system. These controls are predominantly designed to react to feedback from the controlled environment.
A recent study by Mark J. Stunder for the Air-Conditioning and Refrigeration Technology Institute provides a good summary of the state of the industry. According to Stunder, “As building owners strive to reduce operating costs while avoiding occupant complaints, they are likely to increasingly utilize BAS to save energy and to increase occupant comfort. While investment in smart-building technology has been increasing, the science or art of using real-time information in adaptive building management systems is in a relatively immature state.”
Automated building systems, he goes on to say, have traditionally utilized either no local sensors or only a limited number of such sensors. But in our continuing effort to design interactive control systems, we should pay attention to the need for local intelligence and not mere connection. An effort to make all controlled components talk to each other or to a central processor will not provide reliability and performance expected by building owners. Current electronic controls are capable of performing a reasonable default task if the interconnection lines are interrupted for any reason. But additional intelligence can be built in by assigning a “signature” for each parameter, device and element, so figuratively, when devices or systems “shake hands” for whatever reason, the BAS will be able to identify all the needs, capabilities and limitations involved.
Granted, local sensors require routine maintenance. But the same information can be gathered by other means, such as the Internet, resulting in considerable cost savings and efficiency. Furthermore, the cost of adding a control point to a BAS system is less than $30 per point compared to $500 per point in 1980, and these prices are dropping. The total cost of operation and maintenance of building systems—including their environmental impacts—on the other hand, is increasing, and so is the desire to reduce these costs. Regulating agencies and construction code authorities are increasingly enforcing stricter energy efficiencies and environmental policies. These forces, coupled with the availability of low-cost communication systems and access to real-time information via the Internet, have created a fertile ground for building industries to move toward an integrated and global approach for operational optimizations.
Such an approach might be dubbed “predictive feed-forward control using real-time global optimization systems (GOS).” Part of this solution involves the application of building simulation tools to real-time information. A body of documented practice and research by Zulfi Cumali of CCB/Cumali Assocs., San Francisco, addresses the use of such tools and techniques in an integrated and global setting where real-time decision-making for control strategy of system components can be applied in a proactive and predictive way. Actual commitments to such systems, however, are currently limited to research, educational and industrial applications.
But the means are available. Again quoting Stunder, “Internet technology has now progressed to the point where it can be a source of real-time information for predictive purposes in managing buildings. Proactively managing and operating building systems in accordance with actual or anticipated conditions should increase space comfort while reducing operating costs.”
Interactive connectivity of all control components, coupled with the processing power of a simulation engine as an optimization tool, can provide a smoother control strategy that will also reduce the cost of utilities as well as maintenance.
And high-level analytical research has been conducted toward the application of simulation-assisted dynamic building strategies (Mahdavi, 1997) and integration of control and building performance by open or communication protocols (Azzedine Yahiaoui, 2003). There are now validated knowledge-based algorithms for thermal load predictions using real-time weather forecasts (Tse, 2003). Faster simulation models are also emerging that eliminate unnecessary calculations by efficiently merging computational fluid dynamics with building simulation techniques. For example, via the communicating objects method, physical components of buildings such as walls and spaces are modeled as computational objects. These individually solve the appropriate physical equations and exchange changes of surface values, such as temperature, when necessary. Because the object structure is derived directly from the building structure, and because generic objects are reused, simulators can be generated with very low effort. Based on object-oriented modeling and automatic code generation, new physical effects can be integrated easily. This method is fast because calculations are only generated by changes. Fast and accurate responses to external events can also be accomplished. Both features are necessary for real-time tests of the BAS definition of object structure.
What’s the BAS industry up to?
So where are we? As the basis for this study, a survey of existing scientific research in computer-assisted modeling was conducted along with interviews and research into the offerings of a sampling of control vendors.
Meetings with industry representatives confirmed that the commercial and residential construction industry has not yet taken advantage of technology with feed-forward real-time GOS concepts. Some isolated basic tasks, such as a morning warm-up cycle, have been developed with built-in intelligence to learn from the historical start time, as well as the building’s response to optimize start-up times. Most manufacturers now offer wireless thermostats and controllers. Almost all offer some sort of Internet-based real-time data gathering. Johnson Controls (JCI) and Trane, for example, are involved in developing their products for further networking and web accessibility. Trane, specifically, offers building and HVAC system simulation tools with limited capabilities (Trace 700, System Analyzer) that can accept real-time weather data. Trane has also started using PDA-based diagnosis devices with success.
JCI, last year, introduced its web-based services. The company has already installed a predictive HVAC and lighting control system at John F. Kennedy Airport in New York that receives information from flight data system management and prepares the appropriate gates for passengers before they arrive, while simultaneously informing the janitorial crew of a request to service accordingly.
Other interesting JCI developments include the use of a wireless Blue Tooth-capable control system that is used for integrated controls in the automotive industry. JCI has also done work with security systems where a proximity card-access system can power up lighting and HVAC system for individual workstations.
Carrier, which just acquired Atlanta-based web-control BAS manufacturer Automated Logic, is now offering a web-user interface to its own network for monitoring and control of systems over the Internet ( https://ccnweb.homeip.net/demo/waterLoop.htm ). The company also offers wireless thermostats and receiver controllers for both commercial and residential lines. Over the last five to 10 years, the company notes, the use of Ethernet-based controls using the TCP/IP protocol has been growing steadily. But one of the most popular control systems it currently offers is a demand-controlled ventilation module that responds to CO2 sensor feedback and pays for itself in two to three years by optimizing the amount of outside air introduced into the system.
Despite the possibilities, market demand is ultimately what will prompt the major BAS players to push forward with GOS technology. That being said, it is also beneficial to look at our future buildings from human, technological and organizational perspectives.
Human perspective. This criteria factors comfort, flexibility, active participation and contribution of each individual to the mode and mood of one’s environment. It’s not so hard to conceive that everyone will carry their own electronic signature via some device. This information, of course, can be altered on demand by simply logging onto a web page. With this data, a building’s GOS can serve people without having to work blindly to meet some predetermined and rigid setup.
Technology. Components and services for GOS are already in place. And this is good because building owners do not necessarily want to spend more than what they are already spending on BAS systems. Web-based services will be created to maintain and update personal preferences. Most cell phones currently are capable of web browsing already, and every individual’s cell will also be his or her environmental controller. This requires development of higher speed wireless-web access systems by personal PCs, PDAs and phones for faster response. A PDA can further communicate to a person’s destination his or her arrival or departure time based on calendar-scheduling functions.
Organizational changes . The cell phone industry may very well expand to offer comfort and entertainment services. Businesses may be able to eliminate personal phone extensions and simply log their employee’s cell phones into their systems. The cost of comfort, communication and Internet access will be distributed on an individual basis. Offices themselves will shrink to spaces used mostly for occasional conferences and physical archives, as homes can provide virtual office and meeting spaces.
Its a World-Wide-Web world
Research supports the feasibility of real-time global automation systems. The industry is rapidly moving toward the convergence of technology and science that will push building automation closer to the operational status desired by building owners. Today’s easy access to bidirectional web-based solutions and a strong desire to minimize financial and environmental exposures are driving buildings toward implementing this presently existing technology that will communicate needs and actively contribute to decision-making and operation in real time.
Miscellaneous BAS Factoids
MIT has a project called Programmable Building in which every device and light fixture in the building has an IP address for remote web control.
Creative financing methods such as own-and-operate systems and lease-back-to-the-building-owner have been suggested for promoting the new technologies. Issues such as tenancy and consumer accounts in these methods should be addressed. Elevators and lifts have been handled this way traditionally.
Codes govern minimum performance levels primarily for life-safety purposes. A higher level of performance demanded by a code authority will improve the investment potential in the new technology.
In systems cost analysis, “whole-life costing” is more attractive than just life-cycle costing.
Wireless technology seems to expand without a check on its health side effects. This issue may turn into a challenge for this technology.
Another challenge will be provisions for back-up systems when web-based controls are interrupted.
Dr. G. Augenbroe’s Netherlands BS 03 conference research paper:
International Building Performance Simulation Assn.’s site:
Early BAS projects at Newcomb & Boyd:
Federal Energy Management Program:
Article by Anto Budiardjo, Clasma Inc., on Pragmatic Open Building Automation Systems:
Dept. of Energy:
A virtual tour of a DOE showcase facility:
Market Study—A $14.5 Billion Industry by 2006:
IFMA World Workplace 2003 presentation on interoperability and the virtual building model:
11 major automation trends:
Cell Phone Controls—Building Automation Systems Arrive In The 21st Century:
Preparation for an inevitable future—Ultra high-speed networks in 18 Utah cities:
BAS product information:
Siemens Adaptable BAS software, controllers and end devices:
Total Package Open Protocol Building Control System by Staefa Control System/Talon:
Automated Logic’s web-based system:
Integrated BAS with illustrated example: