Electric Submeters Help Bethke Elementary Achieve Nation's First LEED For Schools Gold Rating
New elementary school's building automation system uses E-Mon D-Mon submeters to track electrical consumption and demand, a key measurement required by high-performance building assessment programs like the USGBC's LEED and GBI's Green Globes rating systems.
Since its doors opened for business in August 2008, Bethke Elementary School in Timnath, Colorado has gained national attention as one of the state’s most outstanding K-5 learning environments. To Principal Ann Alfonso, Bethke is a hands-on community that values close partnerships. “It’s very satisfying to see our staff, parents and families pulling together to create the kind of atmosphere that facilitates educational excellence by optimizing the learning potential of every student. The late Dr. Bethke, our namesake, used to say, ‘There has to be a better way.’ We’re proud that Bethke School exemplifies that vision, not only for our students but for the entire community,” she said.
No small contributor to the school’s growing reputation for excellence is the 63,000-square-foot physical plant itself. Late last year Bethke was named the nation’s first Gold-certified facility under the U.S. Green Building Council’s (USGBC) ‘LEED for Schools’ rating system—an honor that was duplicated by the first “Three Green Globes” award for schools by the Green Building Institute (GBI).
Sustainable Design Features
As Poudre School District’s first prototype school to be submitted for LEED certification, Bethke’s improved energy-efficiency measures help to reduce facility operating costs by up to 50 percent through use of an indirect evaporative cooling air-conditioning system, high-efficiency boilers, operable windows, 90 percent day-lit building spaces and other leading-edge sustainable design features. Renewable energy use has already replaced traditional power-generation. Poudre School District energy manager Stu Reeve notes that Bethke currently buys 100 percent wind power from Xcel Energy, but the facility design also incorporates the electrical harness for a yet-to-be-installed photovoltaic system that will provide sunlight-generated on-site electrical power in the future.
Building Automation System
Of special interest is the brain of Bethke’s operational infrastructure, the Building Automation System (BAS) that monitors, controls and reports on the operational condition of the school’s building envelope. Defining the system’s energy measurement parameters was a collaborative effort between district energy manager Stu Reeve and Rick Webster, project manager at LONG Building Technologies, a developer of energy management and building automation systems in Ft. Collins. Sorin Barbalata, P.E., reviewed and signed off on the final design prior to installation.
Data Acquisition Front End
The BAS continuously gathers electrical data in the form of kilowatt hours (kWh) consumed and peak demand (kW) for evaluation and reporting by the school district. The raw energy data is collected every 15 minutes and communicated to the energy manager’s PC via the facility’s Ethernet local area network. The raw energy data is provided by three Class 2000 electric submeters from E-Mon, LLC of Langhorne, PA, a leading provider of energy monitoring hardware and software solutions. Familiar with the E-Mon products from installations at other PSD schools, the building’s consulting engineering firm knew them to be good performers at a competitive price. One E-Mon D-Mon is installed on the kitchen panel board and another on the mechanical room panel board (Figure 3). A third E-Mon D-Mon monitors the lighting system panel. The three-phase, four-wire meters monitor 200A and 250A circuits using 480Y/277V and 208Y/120V configurations, respectively, and communicate the data in the form of a pulse output to the monitoring location.
How Submeters Facilitate the Sustainable Environment
Recent industry studies show that green building construction will continue as a major trend across the facility landscape for the foreseeable future. As front-end energy data acquisition devices, submeters can contribute directly to certification of facilities of all types under major energy initiative guidelines. The industry’s most widely used sustainable building assessment tool, for example, is the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) rating system. Of the system’s nine categories, the left-hand column in Table 1 lists those areas in which submeters can play a major contributory role for obtaining certification points.
Introduced some 25 years ago, submeters continue to grow in functionality and usefulness, providing great value to school districts like Poudre and other facility operators as “front line” energy data gathering tools. In an era of rising utility costs and tightening budgets, today’s “green” submeters are even coming out of the electrical room to let people see actual energy usage and its impact in terms of CO2 emissions, kilowatt hour (kWh) dollars and other parameters that can be easily understood by non-technical people. Submeters not only improve the facility’s bottom line, but facilitate compliance with major energy initiatives while also encouraging every level of the enterprise to become a stakeholder in the energy management and conservation process.
Bethke Goes for the LEED Gold
Designed by Ft. Collins-based RB+B Architects using PSD’s nationally recognized Sustainable Design Guidelines, Bethke incorporates lessons learned from three previous prototype schools designed and built by PSD and its partner firms. One of these, Lakewood, CO-based Shaffer • Baucom Engineering & Consulting, is a full-service mechanical and electrical engineering design firm specializing in LEED projects. Poudre tasked SBEC with designing the new $9.9M facility’s operational infrastructure with the latest high-efficiency electrical and mechanical design and construction features. As SBEC’s senior electrical designer on the project, Art St. John said “the teamwork between the school district, architect, consultants and suppliers was instrumental to our overall success and to the delivery of a quality finished product” that achieved 10 percent lower construction cost compared to other area schools.
In keeping with the facility’s high-performance design philosophy (Table 2), many of the sustainable systems were intentionally left accessible to public view, including structural and mechanical systems, fire sprinkler risers and piping, data management equipment and building monitoring equipment. These and other systems are exposed inside the school to display their functions and, in so doing, provide dozens of potential learning opportunities that contributed toward the LEED Gold rating under the Innovation & Design Process category’s “School as a Teaching Tool” credit (3).
Submeters helped Bethke achieve its LEED Gold certification by providing energy data collection capability that may be viewed as consumption and demand on the BAS display terminal and used as a teaching aid by the school. From an operations standpoint, the submeters provide an energy management tool that allows the district to carefully monitor and evaluate electrical consumption for potential corrective action should the kWh / kW levels suddenly trend upward. This system is currently in use at other Poudre School District campuses and, based on these successes, additional installations are being planned for refurbished schools and new construction.
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