As recently as five years ago, school facilities incorporating integrated intelligent building systems were few and far between. Today, the majority of new school buildings are designed to incorporate structured wiring systems that integrate building automation, energy management, and fire-alarm and security functions. In addition, virtually all school administrators who are contemplating new building programs or extensive renovations are examining these systems and weighing costs and benefits. It seems that the question is no longer whether to equip a new or renovated facility with intelligent building systems, but rather how to do it in a way that is smart, economical and flexible.
Why this sweeping change in attitudes? Several developments are making it harder for school administrators and planners to ignore the advantages of integrated intelligent building systems. These include the sizable declines over the past few years in the first costs associated with such systems, the long-term savings in energy use and maintenance costs that the systems have produced, their greatly improved user-friendliness, and the widening trend toward standardization in the building automation/energy management systems industry, which gives customers a range of choices.
Costs and Savings Within the last half-decade, the first costs associated with building automation systems have diminished to the point where such systems have become affordable for a range of commercial applications, including schools. Of course, purchase and installation costs differ according to a facility's size and type, the extent of the systems and the quality of the components, but such systems usually will add anywhere from $1 to $3 per square foot (psf) to overall construction costs.
Two simple rules are useful in making ballpark estimates of the added costs: 1. The bigger the facility, the lower the per-square-foot cost will be. 2. A relatively basic energy management system (EMS) that only controls HVAC functions will be near the $1 psf end of the range. Costs will mount with every additional building system that is brought into the overall building automation system (BAS), eventually approaching $3 psf.
Another, closely associated reason behind intelligent building systems more widespread acceptance has to do with the long-term cost savings these systems enable. The savings come from energy conservation and reduced maintenance costs. Centralized, computer-based building automation systems are more efficient than previous generations of stand-alone control systems, whether pneumatic or electronic. In a new facility, it is not unreasonable to expect that energy use can be cut by an additional 25 percent below the energy efficiency standards mandated by current building codes.
Moreover, energy-use savings can accrue so quickly that it may be a bit of a misnomer to refer to them as long term. It is quite possible, depending on the size of the facility and its energy-use patterns, that the additional initial costs of an integrated EMS can be paid back in lower energy bills in just a few years.
Maintenance-related savings, though harder to quantify, also are significant. For one thing, integrated building automation systems permit centralized monitoring and control-eliminating much of the legwork that is required when maintenance personnel must travel to equipment rooms or sensor locations to inspect devices and correct problems. For another, the system operator's direct connection to the facility's large equipment-chillers, boilers, air-handling units-permits remote diagnosis of problems as they develop. The building automation system issues warnings when component failures are likely to occur, giving the operator time to order parts and schedule repairs. The likelihood of catastrophic failures all but vanishes.
Beyond these advantages, many building automation systems incorporate artificial intelligence that enables them to be self-calibrating. For example, as part of ordinary operation, a system may perform temperature control subroutines that study the historical data generated over the course of months and then adjust control variables to stabilize and optimize the system's operation.
User-friendly systems A third reason for intelligent building systems' proliferation in new school facilities has to do with increasing user-friendliness. It was not too many years ago that running such systems required the operator to be knowledgeable in DOS-perhaps even to learn a computer language. Today, however, the user interfaces for building automation systems are Windows-based programs that allow easy access to the information these systems can provide. So many people are acquainted with Windows-based software, which means BAS procedures usually can be mastered in a half-day training program.
Similarly, the display screens that convey information to the user have become easier to read, understand and manipulate. The graphics that provide data about the HVAC system, lighting system, fire alarms and sprinklers, and security devices are clearly keyed to building floorplans, and the information displayed is updated so operators have continuous, real-time feedback on how each system component is working.
Moreover, centralized control of building systems has become portable. When building automation/energy-management systems are connected to a facility's data network, it is possible to access building-operation information-to monitor what is occurring, change settings, and perform audit and maintenance functions-from any point on that network. The system manager can sit down at any network terminal or plug a laptop into an available access port, type in the password and start working. Remote access through an ordinary modem/telephone line is possible, allowing a system operator to have access to data from home or while traveling.
Finally, what until recently stood as a major hurdle to truly integratable intelligent building automation systems seems, at long last, to be falling. Until a few years ago, virtually all BAS/EMS manufacturers used proprietary protocols, meaning that different vendors' systems and components could not talk to each other. Though manufacturers did not advertise the fact, these proprietary systems severely limited customers' options; integration could be achieved only if all of a facility's building automation systems-and all components-were made by the same manufacturer.
That is no longer the case. A number of major BAS/EMS manufacturers are complying with the standardized BACnet protocols developed and promulgated by the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE). Although standardization of protocols is not yet universal, the industry is definitely headed in that direction, and the variety of BACnet-compliant systems and components is great enough that administrators no longer have to worry about being locked into a particular vendor's products for the life of the BAS.
The sophisticated features incorporated into the energy management system at the New Milford High School in New Milford, Conn., are not cheap-they are free. Like many utilities around the country, the local power company, Northeast Utilities, offers a rebate incentive program to help its customers buy expensive, energy-efficient equipment and systems that might otherwise break the budget. For New Milford High, Northeast's Energy Conscious Construction Program provided rebates totaling nearly $560,000 for the purchase of variable-speed air-handling control, high-efficiency chillers, variable-speed pumping for hot and chilled water, and energy-efficient lighting.
But that is only the beginning of the story. An energy-use simulation performed on the high school's HVAC system design shows that these features will bring yearly energy consumption way down-approximately 25 percent below that of a facility of equivalent size built to code-mandated energy-efficiency standards. For the 280,000-square-foot high school, that will translate into savings of about $100,000 a year.
The term intelligent building can be somewhat confusing, since it can refer to two different kinds of systems. On one hand, there are the telecommunications and computer network systems that are designed to make a building's users more intelligent; on the other are the building automation systems whose goal is to make the building systems-and the operators-smarter.
In some complex, high-end installations, these two systems may be joined, as on new or fully retrofitted college campuses that employ one-card identification systems. In such systems, building functions, such as security, may be integrated with administrative functions, including library use, meal plans, etc.
Those highly sophisticated systems often are out of the budgetary reach of public and many private schools. Therefore, it is the building-function side of building intelligence-with the enhanced operational control, the potential savings from reduced energy use and the streamlined maintenance procedures-that is attracting the interest of school facility managers.
Even within this arena of building intelligence, the terminology tends to be a bit confusing, because the systems that control building functions are known by several different names, whose meanings more or less overlap:
-A building automation system (BAS) links microprocessor-controlled building functions including heating, ventilating and air-conditioning (HVAC); lighting; elevators; security devices (cameras, card readers, alarms); and fire alarms, smoke sensors and other fire-protection devices.
-An alternate term, synonymous with BAS, that is in widespread use is building management control system (BCMS). In a BAS (or BCMS), information generated by the little brains that monitor and control each of the systems is brought together at the head end-a computer that serves as the big brain for the entire system.
-Another term that is sometimes used as if it were synonymous with BAS is energy management system (EMS). Actually, the meaning is slightly different. An EMS is a subset of a BAS-the part of the BAS that allows centralized monitoring and control of building systems (HVAC, lighting) that account for the bulk of a facility's energy use.
In the latest, best-designed intelligent building systems, all the component systems share a common wiring/cabling infrastructure. This infrastructure is often referred to as a backbone.