How Energy Management Increases Efficiency

Credit: iStock/nadla

Call it what you will—building control, building automation, or energy management—but controlling the flow of electrons in buildings is becoming increasingly prevalent as a way to limit costs and increase efficiency.

Commercial building owners and managers continually juggle the demands of reducing energy consumption and the challenge of monitoring and controlling electricity used by plug-in devices. Increasingly, they are turning to energy management systems to help them achieve both goals.

According to the US Department of Energy (DOE), plug-and-process loads account for about one-third of primary energy use in commercial buildings. PPL efficiency has become the target in achieving energy goals. Alerton is helping building managers save as much as 40% on their electricity costs through energy management systems.

An article written by Kevin Clinger, senior manager of customer marketing for Alerton, explains how effective energy management systems are at monitoring and controlling HVAC systems, stating that many buildings use efficient heating and cooling systems that are optimized with building automation systems.

Combined with more energy efficient building envelopes, it means that the last frontier for additional energy savings consists of lighting and plug loads. Plug load is the energy used by equipment with a regular AC plug. It typically excludes building energy for sources like HVAC and lighting.

The DOE estimates that plug loads account for up to 50% of all energy used in commercial buildings. Fortunately, advanced BASs allow integration of control of HVAC, lighting, and plug loads in one front-end platform, allowing building managers to maximize savings.

System Details
Founded in 1981, Alerton (a Honeywell business) is a leading manufacturer and pioneer of building automation systems for heating, ventilation, and air conditioning equipment. In 2014, Alerton launched the Ascent Building Management System, combining the BACnet protocol and Tridium’s Niagara Framework in a single controller for more effective integration of multiple building systems.

The browser-based HRML5, wireless system monitors system variables through the building, says Kevin Callahan, owner of Alerton. Those systems include HVAC, lighting, security access, and more. “We can see how much electricity the whole building is using, but we can also pinpoint specific areas to determine if the usage is lighting or load. It helps recognize where, when, and why energy is used.”

Alerton has partnered with Ibis to offer InteliNetwork, which provides real-time data on plug-load energy use to empower effective control of plug loads. The system includes a simple-to-install retrofit for wall outlets and a cloud-based management console. Because these Ibis InteliSockets are also BACnet devices, they can easily be brought into Alerton Compass software to be managed alongside HVAC, lighting, and other building systems. Using these tools, building managers can schedule selective shutdowns to individual plugs, while leaving power on for critical equipment in the same room.

Compass, part of Alerton’s BACtalk Ascent product line, replaces Alerton Building Suite and Envision for BACtalk as the operator workstation. It features advanced alarm management and Lightweight Directory Access Protocol authentication to support any mission-critical facility, including those requiring FDA CFR21 compliance. Enhanced reporting and a secure SQL database allow generation of compliance reports, while LDAP authentication enables scheduling of secure emails.

In any building, the building owners and operators have equipment that is drawing an unknown amount of power. “Without that knowledge, it’s difficult—if not impossible—to identify the biggest opportunities for saving energy,” writes Clinger. As the old adage goes, you can’t monitor what you don’t measure.

The system also can be used to monitor and manage the power supply to a wide range of equipment, such as that found in hospitals, universities, office buildings, laboratories, schools, and other facilities. It ensures continued power to essential equipment and predicts potential equipment failures if power usage changes. Not only does this help avoid disruptions, it also saves money.

Goals
Cost savings was the goal for two Texas projects. A popular Texas snack food company with 12 distribution centers needed to reduce energy demand in order to avoid demand charges. “If their demand exceeds the limit, they are assessed monthly charges,” explains Callahan.

They chose a system to monitor and manage electricity usage. “They need to know where they’re using electricity,” continues Callahan. “Are there anomalies, consistent spikes?” By monitoring the rate of consumption and the point of usage, they’re able to turn off non-critical load and stay within their monthly limit.

Similarly, Callahan says several Texas schools are using an energy management system to schedule things to turn off. Installed in both old and new buildings, it helps the school system reach its goal of keeping costs down.

Being able to see the profile on equipment empowers a building manager to make necessary adjustments for continued efficiency. Watching for patterns over time alerts the building manager to decreases in efficiency as the equipment ages. “The key is coordinating the systems: lighting and HVAC.”

The Triumvirate: HVAC, Lighting, and Plug Load
At one point, HVAC, lighting, and plug loads accounted for about one-third of energy costs in uncontrolled buildings. HVAC and building envelopes have become much more efficient, leaving lighting and plugs loads to become more significant savings opportunities.

BAS can help achieve energy savings while still providing comfortable working environments and safe, reliable building operation. One way it does this is by running building systems only when needed, using timers and sensors to turn off systems when no one is using them, such as after hours, at night, and on weekends, as well as during business hours when an area is unoccupied.

A standby mode balances energy savings and costs by reducing equipment cycling. Clinger explains: “Whereas the unoccupied mode might set the thermostat 10 degrees lower than the occupied mode, the standby mode might lower the set point only three degrees to reduce heating demand, yet preserve comfort for occupants who are momentarily out of the space during regular facility hours—such as a school class that goes to a brief assembly or outside for a fire drill. Scheduling could then set the HVAC system to the lower unoccupied level during the facility’s customary closed or low-demand hours.”

The DOE estimates that occupancy and vacancy sensors reduce electricity waste by 30% or more. Nevertheless, additional energy savings can be achieved through lighting management, with automated lighting controls, motion sensors, and passive infrared sensors. Lighting is the second-largest user of energy in schools and hospitals; it accounts for 20% of total energy consumption, according to the DOE.

It’s common to see the installation of occupancy sensors in retrofits. In schools and office buildings where rooms are typically unoccupied at night, it can create great savings. Daylight harvesting is another method of saving energy when combined with automated lighting controls that dim electric lights when sunlight is available. The added benefits of worker productivity and well-being make daylight harvesting a pop­ular option.

Credit: Hudson and Associates
Magruder Elementary School relies on advanced
building controls to integrate with its variable refrigerant flow (VRF) heating and cooling system.

HVAC and lighting aren’t the only areas where additional savings and efficiencies can be reaped. Clinger refers to plug load as the “final frontier” for efficient buildings. He says the principal offenders when it comes to electricity waste are air conditioning units and photocopiers. Like lights, air conditioners are often left running when no one is in a room, while photocopiers draw substantial power even when they’re in sleep mode. “With plug load monitors integrated with a well-appointed BAS, facility managers can evaluate the biggest power drains and automatically turn off equipment when it’s not needed.”

BAS
To achieve improved efficiency and better control of HVAC, lighting, and plug loads, a coordinated building management system is necessary. A BAS controls energy-consuming equipment in a building to reduce energy use while maintaining a comfortable environment. The primary components of the BAS system include sensors, controllers, actuators, and software.

These systems are currently in more than half of all buildings in the US larger than 100,000 square-feet and may include features such as maintenance planning, fire- and physical-safety functions, and security services.

Typical functions BASs use to reduce energy usage include:

  • Scheduling to turn equipment on or off according to the day of the week, time of day, or weather.
  • Lockouts to keep equipment from turning on when it’s not needed, coordinated with dates, specific temperatures, or other parameters.
  • Resets when equipment operates at a greater capacity than needed to meet building loads to meet weather conditions or other parameters.
  • Diagnostics to monitor and troubleshoot things like flow, pressures, actuator positions, temperature, and other data that indicates if the equipment is running correctly and efficiently. Some systems also provide maintenance notices.
  • Limit demand to shed load. Electrical demand charges can make up 40% or more of a utility bill, so predetermined set points can be programmed to keep those charges in line.

As Clinger points out, in buildings where multiple computers control different systems, it’s difficult for a facility manager to optimize each system due to different platforms. With an advanced BAS, you enter scheduling information once and can jointly monitor and control multiple systems, Clinger elaborates. “Picture a facility operator in a K-12 school planning for winter break. With an integrated BAS, they can schedule the HVAC, lights, and plugged-in equipment all to be turned down or off while the students are on vacation.”

While monitoring and control can help reduce plug load costs up to 40%, there are also other benefits, such as reliable building operations. Some equipment must remain on, such as refrigerators in hospitals, labs, food processing, and retail locations. A BAS will sound an alarm if the specified equipment stops running, allowing the building manager to take quick action before mission-critical system failure causes cataclysmic damage.

Graphic interfaces enhance BAS coordination, making it easy for a building manager to see at a glance what is going on. Alerton Compass software uses OmniGraphics to transform background images into interactive building controls to visually communicate system status. “Visual controls such as this enable even novice users to quickly get up to speed on controlling multiple building systems,” indicates Clinger. Alerton’s OmniZoom graphics automatically adjust to the monitor display size for better visibility and system management.

Research indicates a wide range of energy savings for BASs from none to annual savings of more than 30%, although the average energy savings is between 5 and 15% of overall building energy consumption. The savings can be greater for older or poorly maintained buildings, states Kristin Kamm, senior research associate at E Source.

BASs provide the data to show how much you’re saving and help identify opportunities for additional savings. Although it depends on how inefficiently the building was operating before installation, according to the Minneapolis/St. Paul area’s Metropolitan Energy Policy Commission, BAS can save building owners and operators from $0.20 to $0.40 per square foot in utility costs per year. For an average-sized hospital or grade school of 75,000 square-feet, that adds up to a savings of $15,000 to $30,000 annually.

Use It or Don’t Lose It
As Kamm points out, simply installing a BAS is not enough to guarantee energy savings. She says many BASs save less energy than they are capable of saving. “In one detailed study of 11 BAS-equipped buildings in New England, five were found to be underachievers, producing less than 55% of the expected savings. One site produced no savings
at all.”

Credit: Alerton
Compass software, part of the Alerton Ascent building automation system (BAS), provides a simple-to-use graphical interface.

In order to reach energy savings targets, building managers must use advanced control strategies that use the computer-processing power of a BAS and adopt a comprehensive approach to quality control referred to as commissioning. Commissioning includes reviews and inspections throughout the design and construction process as well as rigorous performance tests that move the system through its sequences of operation before the building is occupied. Kamm explains that this process is now required for some buildings, such as those with Leadership in Energy and Environmental Design certification.

Recommissioning entails using trending and energy consumption data to periodically verify, document, and improve a building’s operation. This process ensures that the system continues to work properly and is useful for identifying broken components, recalibrating sensors, and correcting control functions that have been disabled by building operators, Kamm reports.

The Future: Smarter BASs
The “next big thing” or driver, Callahan believes, is the addition of data and cloud computing power and analytical software, allowing building managers to get reports and visualize energy use. “Why are they using electricity? You can gather data, send it to the cloud, run analytics—but can you understand it?”

He is a proponent of information being presented in a way the building manager can understand and of providing an action plan to manage the utility. “Know what to do! Data provides answers to questions.”

BASs are becoming smarter as they begin to incorporate more powerful algorithms based on artificial intelligence techniques. Kamm mentions Optimum Start and PID controllers that have adaptive capabilities, which minimize efforts needed to tune these algorithms for the specific building and systems. Third-party software applications detect faults and operating inefficiencies in building systems.

“These applications can measure the performance of a building system and compare it to a modeled performance benchmark. When differences arise, the system can use these powerful algorithms to diagnose the problem and then alert the building operator,” believes Kamm. Eventually, the capability to monitor performance will become integrated with BASs to enable automatic system corrections.

Use of AI makes a building autonomous, Callahan says. “It doesn’t need someone watching. The building knows what it needs to do to be comfortable and safe; it will recognize a problem and act—call maintenance, etc.” Breaching predetermined parameters will trigger action by the building without additional human input. As incredible as it sounds, Callahan believes that “we’re at the dawn of the cloud service industry. There’s still a lot left.”

References
http://www.automatedbuildings.com/news/apr07/articles/esource/070322105430kamm.htm

http://bea.touchstoneenergy.com/sites/beabea/files/PDF/Tech/SavingEnergywithaBuildingAutomationSystem.pdf BE_bug_web

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