06/24/2014

Submeters Measure Energy Savings, Help Drive Campus-wide Building System Upgrades

 
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    This article is sponsored by Honeywell E-Mon LLC, to learn more visit http://www.emon.com/

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    Figure 1. Ravenscroft School needed an effective, economical way to monitor and evaluate energy and natural gas usage in its largest buildings. E-Mon D-Mon submeters were selected for their ability to tie into the building management system for a centralized way to monitor the school’s energy profile. In the process, facility managers learned more about how, when and where the energy was being used—justifying new building system upgrades.

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    Figure 2. Chris Farrow, Director of Buildings and Grounds, reviews meter data used to baseline seasonal energy usage. The kWh / kW data helps the facilities staff optimize building system performance to reduce energy use and to cut cost without sacrificing the comfort and quality of the classroom environment. The data also helps managers justify and prioritize building system upgrades and retrofits.

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    Figure 3. One of ten Class 3000 E-Mon D-Mon meters monitoring 400 to 3200A circuits in seven campus buildings. The meter’s Modbus IP communications option allows direct connection to the building management system (BMS) via the Ethernet link plugged into the jack above the meter. The upper jack is the out-bound link to the central monitoring location. The flex conduit beneath the meter brings in the voltage and current readings from the circuit being monitored, in this case the Fine Arts building’s consumption and demand profiles.

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    Figure 4. Ravenscroft staffer Johnny Jernigan adjusts mounting of the EMon D-Mon meter installed in a campus building. The thin black cable plugged into the jack at the top of the photo is how the meter data is transmitted back to the monitoring location.

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    Figure 5. Scrolling display of the meter mounted in the Library & Tech Center shows a total of almost 478,000 kWh of monitored electrical consumption since the meter was installed.

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    This article is sponsored by Honeywell E-Mon LLC, to learn more visit http://www.emon.com/

Steve Kearney
E-Mon

Founded in 1862, Ravenscroft School serves some 1,235 students in lower (pre-K-5), middle (6-8) and upper school
(9-12) divisions on a beautiful 125-acre wooded campus in Raleigh, North Carolina. As a non-profit coeducational
college preparatory day school with more than 200 full-time employees, Ravenscroft appears to be
well on its way to realizing its stated goal of becoming the area’s leading independent academic
institution and one of the top schools of its kind in the Southeast.


In addition to academic excellence, as evidenced by the Class of 2011’s four National Merit
Finalists, two National AP Scholars and significant AP class participation; Ravenscroft also emphasizes a strong sense of community involvement and environmental stewardship. To that end, a number of
campus-wide sustainability initiatives are already producing successful outcomes, thanks in large measure to the
high level of participation by the school’s faculty, staff and student communities.

Ravenscroft goes green

Under the leadership of Doreen C. Kelly, Ravenscroft’s Head of School, vision of weaving sustainability into the
fabric of the school’s culture is playing out on campus in a number of ways. In addition to recently implementing
composting in the dining hall, the school is further reducing its carbon footprint through more aggressive recycling,
dual-flush toilets, light / motion sensors and other energy conservation measures.

In 2008, Ravenscroft joined the Green Schools Alliance and now competes against other area schools in the GSA’s
annual Green Cup Challenge. On the heels of admirable showings in previous contests, in 2011 Ravenscroft tied for
first place among Carolina schools by reducing its electrical consumption by more than 10 percent, thus preventing
almost three-and-a-half tons of CO2 from being injected into the atmosphere.

As the primary energy data acquisition tool, electric submeters not only played a key role in measuring and verifying
building performance for the Green Cup Challenge, but also provided accurate energy consumption and
demand profiles for all metered buildings on a 24/7 basis. With the exception of the Murphy Hall chiller plant, in
which only an electric meter was installed, seven other campus locations totaling more than 259,000 square feet
were metered to track both gas and electricity (Figure 2).

How submeters facilitate the “greening” process

In response to challenging “green” applications like Ravenscroft School, E-Mon and others have
developed advanced hardware and software tools that specifically address the measurement and
verification (M&V) needs of the sustainable facility market. Certified to ANSI C12.20 nationalaccuracy standards, advanced-capability submeters offer a number of important functions for both new construction
and retrofit applications, including:

  • Scrolling LCD display of kilowatt-hour (kWh) usage;
  • kWh in dollars;
  • Current electrical demand load in kilowatts (kW);
  • Cost per hour, based on current load;
  • Estimated CO2 emissions in pounds, based on DOE standards;
  • Estimated hourly CO2 emissions based on current load;
  • Net metering, including utility-delivered vs. user-received power and net usage;
  • Compatibility with BACnet, Ethernet, LonWorks, Modbus and other leading building automation system communications protocols;
  • Compatibility with pulse-output utility meters, including water, gas, BTU, steam, etc.;
  • Optional integration with automatic meter reading (AMR) systems for billing and analysis;
  • Optional presentment of energy usage and carbon footprint data via easy-to-understand dashboards accessible from any standard web browser, both for single buildings and campus-wide meter networks.

Ravenscroft’s decision Ravenscroft’s decision to install advanced metering (Figures 3 and 4) was based on feedback from
both internal and external sources. One Ravenscroft parent, Joe Hirl, is also an electrical/nuclear
engineer and veteran energy-industry consultant. “The perspectives of medium and large energyefficient, but also a requirement to be smart on capital outlays to improve efficiency. Consumers are now inundated with calls from service and equipment providers claiming to have the best energy-saving solution. In reality, companies need to first truly understand how they are currently using their energy before they jump on a ‘single’
solution.”

With that in mind, the Sustainability Committee and the Board of Trustees spearheaded a comprehensive energy
audit to benchmark Ravenscroft’s gas and energy use in seven major buildings on campus. The findings of this
study triggered the recommendation to meter, a decision that was rubber-stamped by the interdepartmental
management team guiding the project through to completion. Key decision-makers included:

  • Doreen Kelly, Head of School;
  • Vic Bell, Chairman of the Board of Trustees;
  • Leonard Johnson, Assistant Head of School for Business and Finance;
  • John Replogle, Sustainability Committee;
  • Chris Farrow, Joel Williams, Charles Winston and Bob Wright; Buildings and Grounds Committee;
  • Munther Qubain, Finance Committee;
  • Joe Hirl, Agilis Energy;
  • Robbo Newcomb and Kent Woodard, Newcomb and Company.

Metering system supplies the data

Based on the recommendations of Ravenscroft parents Robbo Newcomb and Joe Hirl, E-Mon was
chosen over the local utility’s solution of interval data recording (IDR) meters. As it turned out, the
local utility’s data recording meters lacked the ability to integrate with the school’s building management system (BMS) for a centralized way to monitor the school’s energy load. Consequently, they were also incapable of functioning as a teaching tool for educating students and faculty on Ravenscroft’s on-going energy conservation initiatives.

Newcomb and Woodard started the ball rolling with their local stocking distributor, Eck Supply, whose Mark Wiese
contacted the E-Mon factory rep, Emery Electrical Sales. Emery’s Jerry Helms coordinated with Wiese to work out
pricing, delivery and other issues relative to delivering the metering system elements in a timely fashion for
installation.

In operation since May 2010, the hardware and software system installation and startup was completed over a
period of about three months by a local electrical contractor, Classic Electric Service, Inc.

The data collection capability of the submetering system is provided by ten Class 3000 E-Mon D-Mon meters with
Modbus IP communications. The circuits being monitored include 277/480 volt, 3 phase, services ranging from 400
to 3200 amps (Figure 5). Additionally, a Web-Mon Enterprise version is being integrated into a campus-wide
Tridium Niagara AX platform building management system (BMS) to provide Internet browser-based real-time and
historical dashboards of all meters in the system. The meter data is collected both wirelessly and hard-wired and is
being stored on the school’s network, which is able to accommodate up to 3,000 data records.

Building management system

In parallel to the metering system, Newcomb and Company, a full-service industrial, commercial and residential
mechanical contractor, installed and conducted training for the school’s building management system, a Tridium
Niagara AX platform which supports standard open protocols like LonWorks, BACnet and Modbus,
to integrate lighting controls, electrical switchgear, generator packages and other building
systems into a total facility management system.

The NiagaraAX software framework is especially useful for device-to-enterprise applications,
allowing non-programmers to build powerful apps in a drag-and-drop environment. This allows Internet-enabled products like E-Mon’s Web-Mon meter dashboard and energy monitor to provide real-time and
historical displays of kWh, kW and other measurements via standard Web browsers from any access point in the
system.

According to Leonard Johnson, Assistant Head of School for Business and Finance, the whole point of the exercise
was to find a way to “monitor individual building energy consumption by time period and then utilize that data in
combination with the installation of a Building Management System to reduce energy consumption. The BMS in
conjunction with our metering system allows us to do that.”

Results and a look forward

In terms of positive impact on operations, “our enhanced understanding of usage patterns and variations has helped
drive decisions to perform a lighting retrofit and measure the results,” says Johnson. “In addition, the meters have
provided the rationale for investing in upgraded building management systems across some of the larger buildings.”

Operationally, everyone agrees that the BMS and metering systems have performed well and as expected. The
school is now in the process of interfacing the metering system with Ravenscroft’s campus-wide Tridium Niagara
AX platform in order to make both the energy monitoring and building management systems accessible to the
educational curriculum.

As a teaching tool, Ravenscroft teachers can now use the meter dashboards to demonstrate how energy consumption
is being monitored. By comparing historical energy consumption data with current levels, the students are able to
contrast the facility’s original energy consumption data before the meters were installed with its current savings in
terms of energy units, dollars and reduced carbon emissions. One teacher has taken it a step further and tags certain
energy-consuming items in his building and manually shuts them down so the students can easily monitor the
reduction in energy use and carbon.

Beyond that, notes Johnson, “the data is also helping Ravenscroft to establish seasonal energy usage baselines,
prioritize upgrades and retrofits and adjust occupied-versus-unoccupied operating hours to reduce energy use and
save money without sacrificing the comfort and quality of the classroom environment.”

Partners in the Ravenscroft story:
Mechanical Contractor: Newcomb and Company, Raleigh, NC: www.newcombandcompany.com
E-Mon Factory Rep: Emery Electrical Sales, Inc., Charlotte, NC: www.emeryelectrical.com
Electrical Distributor: Eck Supply, Raleigh, NC: www.ecksupply.com
Electrical Contractor: Classic Electric Service, Inc., Raleigh, NC: 919-834-3226

About the author

Steve Kearney is Regional Manager for the Southern U.S and Caribbean sales territories of Langhorne, PA-based EMon (www.emon.com), a leading provider of submetering and automatic meter reading (AMR) hardware, software and services. A degreed industrial engineer from Auburn with an MBA from Mercer University, Steve is also a Certified Energy Manager (CEM) and Demand Side Management Professional (DSMP). Steve is a member of the AIIE, IEEE and Atlanta chapter of the USGBC and may be contacted at skearney@emon.com.

 

 
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