Selecting a System

DEVELOPED 25 YEARS ago primarily for use in large, multi-building facilities, energy management systems (EMS) were costly to install and operate. Economy of scale made the systems cost-effective. Smaller facilities simply couldn't afford to make the required investment.

Now, systems are cost-effective in commercial, institutional and industrial facilities of all sizes. Installation and operating costs have dropped dramatically. EMS systems rapidly are becoming a requirement for day-to-day operation. Without them, higher energy and maintenance costs can diminish a facility's competitive position.

That's put facilities professionals in a challenging position. Many lack the necessary hands-on system experience to select one for their facility. The marketplace, meanwhile, compounds the problem. The number of manufacturers offering systems has increased significantly in recent years.

With so many options, how do you select an EMS that's best suited for your facility?

Finding the right system is a six-step process. It starts with an understanding of system capabilities, and continues through the installation process to system operation. By following these six steps, facilities professionals should be able to ease the process of automating the control and operation of energy-using systems.

Step 1: Understanding What Systems Can and Cannot Do An EMS offers facilities professionals a very powerful tool to help manage both the costs and operation of a facility. The most widely promoted function of this tool is reducing energy use through the control of energy-using systems. Most facilities professionals can expect energy cost savings in the range of 20 percent to 30 percent for a fully functioning system.

But an EMS does much more than just reduce energy use. It can monitor and control HVAC systems in remote locations within the same facility, or within multiple facilities. For example, an EMS monitoring chiller operation can sound an alarm, alerting operators that the chilled-water supply temperature has risen. The facility manager then can dispatch a mechanic to correct the problem before building occupants notice rising temperatures. If the problem takes time to solve, the EMS will have allowed the building manager to begin notifying tenants.

Remote monitoring also can improve a facility's maintenance operation: An EMS constantly monitors the operation of connected equipment, comparing equipment status to expected values. The system also can monitor parameters that cannot be determined at a glance during a walk-through.

Detecting problems remotely is only half the problem. An EMS gives the facility manager the ability to start and stop equipment, reset operating parameters and change system operating times, all from a remote location.

And through the use of direct digital control (DDC) strategies, an EMS provides more flexible and more accurate space temperature and humidity control than can be achieved with conventional control systems. Building security needs can be met through the use of access control and alarm monitoring capabilities of the energy management systems. Systems also monitor fire safety systems, providing both remote monitoring of building detection and alarm systems, and smoke management through interfaces with the building HVAC systems.

Meanwhile, nearly all EMS include modules for fire and life safety operations. The systems monitor the status of critical alarms, providing a readout if an alarm occurs. The systems also interact with other building systems, further enhancing safety. For example, the software that monitors fire alarm pull stations and smoke detectors can interact with HVAC systems to help exhaust smoke and with door security system to provide egress for building occupants.

EMS systems are not the cure-all or fix-all for building HVAC and energy problems. Although they can improve both the operation of and the operating efficiency of the systems they're connected to, they rarely overcome existing system shortcomings. No energy management system can overcome HVAC maintenance neglect or design problems; these problems must be corrected before energy management system installation. Too many systems fall far short of manufacturer claims and owner expectations because existing problems weren't corrected first.

Step 2: Determining Your Needs One of the most common EMS purchase mistakes is buying a system that doesn't meet the organization's needs. If the system is too limited in its capabilities, it won't be able to perform all of the functions that would benefit the facility. Similarly, if a system performs functions a facility doesn't need, it also won't benefit the operation.

Before selecting a system or a manufacturer, determine your facility's energy management system needs. Start with a planning team that examines how your facility is operated. What type of HVAC, lighting, security, fire safety, and access control systems currently are installed? How would the performance of these systems be improved by connecting them to a new energy management system? Are there other operations and functions that the EMS supports but aren't currently installed?

A key consideration is the system's estimated size. Systems are limited in the number of connected monitoring and control points they can support effectively. As they approach their effective size limit, system performance degrades. If you select too small a system, you'll be limited in your future expansion capabilities. If the system is too large for your requirements, it won't be cost-effective.

You'll need to survey the entire facility, identifying the functions to be performed, the systems to be connected, and the control and monitoring points that'll be tied into the system.

Step 3: What to Look for in Proposals/Submittals An EMS typically is purchased either through bids or requests for proposal. In both cases, there are a number of items that need to be examined prior to system selection. These items, assuming the system quoted meets the specifications, will determine the installation's overall success.

1. System Availability. No EMS can produce savings if it isn't available to be installed. Manufacturers should quote only on systems currently in production. Require the system manufacturer to state how long that system has been on the market, and how many installations of that system have been completed. You don't want to be the first, or the last, to purchase a particular system.

2. Manufacturer's Reputation. One of the benefits or risks associated with purchasing an EMS is the long-term association you'll be entering into with the system manufacturer. Systems have a life expectancy of about 10 years. During that time, you'll need hardware, software and maintenance support from the manufacturer or from a company licensed by the manufacturer. Additionally, your system most likely will undergo several expansions or major upgrades during its life. Anything less than a good working relationship with the manufacturer will make your life difficult -- and decrease the potential of the system you purchased.

Before committing to this long-term association, check out the manufacturer's reputation. How long has the firm been in business? Will it be here two years from now, when you might need service? How do others who've already installed the system evaluate the manufacturer? How responsive is the manufacturer or the manufacturer's representative to operational or maintenance problems? Does the firm support older-generation systems, or does it pressure owners to upgrade to new systems? Finally, does the system perform as the owner expected, and as the manufacturer promised?

3. Ease of Operation. One of the most important developments in building automation systems over the past five years has been the use of graphical user interfaces. Early-generation systems, with their cryptic command language, were difficult to learn. Most of today's systems have patterned their user interface after the ones commonly found on desktop computers. As a result, the system is fairly easy to learn and use, particularly if your employees already use desktop computers.

Differences still remain between systems, however, that can make learning and using the system simple or difficult. Before locking into a particular system, ask to visit a working site and spend time using the system interface.

4. Expansion Capabilities. All systems have a finite size limit. Be careful not to exceed the system's limits -- the system could perform poorly, even fail to perform at all. To estimate the needed system size, identify the number of control and monitoring points that would be connected to the system. Include any known facility expansions during the next five years. Take the total number of estimated points; then double the figure. Your installed system should be capable of supporting this number of connected points.

Step 4: Acceptance Testing Unfortunately, one of the most often overlooked steps in installing an EMS is the complete and thorough testing of the system after installation. Too often, systems are installed and accepted by the owner, who months later discovers that control points don't respond to commands, temperature or sensor points give faulty readings, or worse, the software doesn't perform as specified.

When the installer notifies you that the installation is complete, a formal acceptance test must be completed to verify that the system is performing as specified. Working with the installer, test every sensor, all control actions, and all software. Items found to be operating improperly should be recorded in a punchlist, with acceptance of the system postponed until they've been corrected and retested.

Step 5: Training Often overlooked, training is critical toward successful EMS operation. First, operators must be trained on how to use the system interface. Although early-generation systems tended to use cryptic, text-based interfaces, newer system use a graphical interface, similar to the one used on today's desktop computers. But users still need to be trained on how to use the interface.

A second level of training is required in order to be able to set up the systems control programs. System control points must be assigned start-stop schedules, setpoints and normal operating ranges. Critical system alarms must be identified, and alarm responses entered. Control sequences must be laid out and entered into the system using the system-supplied programming language. The operators must receive sufficient training not only to use the system tools to perform these tasks, but also to understand the building systems the EMS controls.

A third level of training is required for system servicing. Unless the system is covered by a complete maintenance contract, personnel will have to perform at least some system diagnostics and maintenance. Workers will need to be trained to perform a variety of system tasks, including how to use the specialized test equipment associated with the EMS.

Step 6: After the Sale/Installation The facilities professional's real work begins once the system's installed; at that point, it's his or her responsibility to make the system perform effectively, and keep it performing effectively over the life of the system. An EMS isn't static. Over time, changes will be made to the hardware and software. New monitoring and control points will be added. Some existing points will be modified or relocated to improve operation. And things will fail.

To keep the EMS from becoming an unwieldy beast, facilities professionals must devote time to three key tasks; staffing, maintenance and documentation.

As automated as an EMS is, it still requires staffing. People will have to establish and maintain operating schedules for system-controlled equipment. Control set points will have to be adjusted. Programs will have to be updated. And failed components will have to be replaced. To perform these tasks, the system will have to be properly staffed, with well-trained personnel. If the organization cannot support the staffing in-house, consider implementing a partial or complete service contract for the system.

Finally, document everything. The larger the EMS, the greater the need for accurate documentation. Without it, system maintenance is difficult, particularly as you make changes and upgrades to the original system. If you don't keep track of what, how and why changes were made to the system, it'll be difficult for system mechanics to track down operating problems.