Upgrading Or Replacing EMS System A Big Decision
By James Piper, P.E. July 2011 - Building Automation
Ultimately, the decision to upgrade an existing system, replace it or stay with it will come down to an evaluation of the costs and benefits. Costs can be fairly easily determined. It is much harder to identify and quantify the benefits.
Care must be taken to avoid being drawn into purchasing a system that is loaded with all of the bells and whistles. Chances are many of them are not needed and will never be used. Purchasing a system that includes functions that will never be used will only increase the cost of the system and make it more complicated to operate.
Go back to the original statement of what the system is expected to do. Those are the functions that must be included in any system upgrade or replacement. Facility managers must balance the additional costs associated with functions that are not currently required against the potential that they may be needed some time in the future.
Facility managers must also realistically look at the equipment and components that are to be connected to the EMS. If those systems are in poor condition and have not been properly maintained, it is questionable whether a new EMS will achieve what is expected of it. If the facility's HVAC and other equipment to be controlled by the EMS are not operating properly, facility managers should invest in either repairing or replacing that equipment first. Computerized control of a poorly functioning system will still result in a poorly functioning system. Most likely, the new EMS will overwhelm operators with faults and error messages from the poorly operating HVAC and other equipment, problems that most likely existed before but were never detected. The result will be that operators simply override those functions that are identifying the problems, defeating the purpose of the system.
Similarly, the level of control that is desired by facility managers may not be able to be achieved with the existing installed equipment. For example, to achieve the level of energy savings and system control that can be provided by today's EMS, pneumatic temperature control systems would have to be converted to DDC, an additional major expense that must be factored into the upgrade/replace question.
Considerations Beyond the EMS
Larger facilities that have grown over time may have more than one currently operating EMS. This results in additional operating, maintenance and training costs, and limits the ability to compile information from the entire facility at a single point.
Similarly, facility managers must honestly evaluate the qualifications of those who operate and maintain facility equipment and the EMS. If many of the existing problems can be traced back to inadequately trained personnel, upgrading or replacing an EMS system will not correct the problem. In reality, implementing an upgrade or a replacement will only make things worse.
Finally, facility managers should perform a detailed cost analysis that realistically examines the level of additional savings that can be achieved through the use of an upgraded or replaced EMS. Those savings calculations should include additional energy savings, improved revenue streams like being able to pass on energy costs to building occupants, projected maintenance savings related to the system itself, maintenance and operating savings related to equipment controlled by the system, and labor savings that are a result of the new system's enhanced capabilities. Additional savings can be achieved in some applications by taking advantage of utility company rebates or state or federal tax credits.
There is no question that an EMS can be a very powerful tool for facility managers. But if they are to be effective, they must be carefully matched to the needs of the facility. The systems are not install-and-forget; they require constant attention, adjusting their operation to changing conditions within the facility. They require periodic upgrades to software and firmware. And most importantly, they require that systems and components they control be kept in good operating condition.
James Piper, PhD, PE, is a writer and consultant who has more than 35 years of experience in facilities management. He is a contributing editor for Building Operating Management.