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Energy-Management Systems Put You in Control

Key Points
  • Energy-management systems (EMS) monitor conditions and control energy-consuming equipment. 
  • EMS designs range from single-point control devices to complex, facility-wide systems.
  • EMS systems can control lighting, HVAC, and manufacturing process equipment.

Energy managementEnergy conservation is a team effort, but getting everyone's cooperation can be difficult. Oversights, like leaving lights on in unoccupied rooms, or allowing unused equipment to continue running, can cost your organization a substantial amount of money. Energy-management systems (EMS) can help your facility become more efficient by putting you in control. From a single point, you can measure, monitor, and regulate energy-using systems. A properly installed and maintained EMS can result in energy savings of 10 to 30 percent.

How an EMS saves energy

An EMS reduces energy use by monitoring conditions and controlling energy-consuming equipment. Commonly used to control lighting and space conditioning, EMS systems are versatile enough to automate your entire building. With an EMS, you can track building system operations, perform diagnostics, and optimize performance—saving energy and reducing labor costs. EMS systems typically interface with existing building controls.

An EMS can take various forms, from a single-point control device to a complex system that manages energy use throughout an entire facility. Cross-functional EMS systems provide the greatest potential for maximizing energy and cost savings. Simple systems include actuators that switch or change loads according to signals from local controllers. More sophisticated units include sensors or monitoring points, field termination panels, modems, communication links, and central computers. Centralized controls allow you to interface with remote equipment to diagnose problems.

System components

Systems vary by facility type and the level of control needed. Commonly used energy-management devices include:

  • Timers turn lighting and equipment on and off according to a schedule. Small loads are switched directly while large loads are controlled indirectly with relays.
  • Occupancy sensors detect whether people are present by sensing heat (infrared), motion, or sound (ultrasonic).
  • Programmable thermostats adjust building temperatures automatically, according to operating schedules and seasonal changes.
  • Photocells regulate light levels, dimming or increasing light according to the amount of available daylight. 
  • Program logic controls (PLCs) use sensors to operate process equipment in manufacturing environments for maximum energy efficiency. 

Implementing an EMS

While energy-management devices can reduce costs, they are not right for every situation. To maximize your savings, plan carefully before installing an EMS. Examine your facility, energy-use patterns, and occupancy needs. For example, lighting controls may not be useful for a conference room where meetings are rarely held. Individual devices are relatively inexpensive, but installing a complex system will require a significant investment of time and money; apply it where it will be most effective.

A new system will not necessarily interface properly with existing controls and other remaining components. Use caution when buying proprietary systems, look for products with an open protocol. 

Optimize performance through system maintenance

The following operating and maintenance tips will maximize performance and your energy savings:

  • Calibrate and check sensors regularly. Failed sensors and false readings can waste a considerable amount of energy.
  • Protect control devices from power quality problems with surge suppressors or uninterruptible power supplies (UPS). 
  • Use battery backups for timers and other scheduling devices. Power outages can disrupt energy-management settings and reduce system effectiveness.
  • For safety, post signs that indicate control devices and install disconnect switches near equipment that is operated by automated controls.
  • Train key employees on the overall design intent and proper operation of the system.

Although they require time and effort to implement and maintain, an EMS will help you take charge of your energy use.