Consulting-Specifying Engineer - September 2008 - (Page 52)

Case Study Green campus living L AT A GLANCE Zoned heating in rooms allows for optimal comfort. Pacific University employed the CITI MULTI R2-Series Variable Refrigerant Flow Zoning system to keep its new USGBC LEED Gold Burlingham Hall running efficiently. The compact system allows its resident students to control their local temperature while it optimizes energy use by varying system capacity to meet the load requirements. The hall uses R2-Series equipment: eight outdoor units, 45 of which are ceiling-concealed; three ceiling-recessed cassette and six wall-mounted indoor units; and 10 branch circuit or centralized controllers. As a result, the hall used 25% less energy in its first year than forecast in its energy model. ocated 24 miles west of Portland, Ore., lies Pacific University’s 55-acre Forest Grove, Ore., campus and its four U.S. Green Building Council LEED-accredited buildings. Making it their mission to teach students firsthand the importance of environmental stewardship, Pacific University’s green building campaign encompasses its main library, the Health Professions building, and Berglund Hall, home to the College of Education. Its newest building, and the first USGBC LEED Gold residence hall on the West Coast, helps solidify the lesson of environmental stewardship, linking 161 of the university’s students with nature. Designed to reduce energy use by 33% over national standards, the 59,000sq-ft, 49-unit Burlingham Hall features highperformance windows, high-efficiency lighting systems, stormwater bioswales, low-flow kitchen and bath fixtures, programmable thermostats, and high-performance mechanical and energy recovery equipment, including Mitsubishi Electric HVAC’s CITY MULTI R2-Series Variable Refrigerant Flow Zoning system. Employed for its affordability, compact size, and energy-efficient properties, the R2-Series can heat and cool spaces flexibly, independent of seasonal or directional variations, by varying the speed of its compressor to match the load requirements of each space. With a number of individual indoor units, each zone precisely specifies its own temperature while the system’s inverter technology varies system capacity to meet the demands, providing indoor comfort simultaneously. How it works When responding to both indoor and outdoor temperature fluctuations, the R2-Series system varies power consumption by adjusting its compressor speed and optimizes energy usage with the use of its eight branch-circuit and two centralized controllers. Tucked neatly above the building’s bathroom ceilings, 45 individual indoor units are readily accessible for long-term maintenance, but concealed from the residents. The lightweight and small footprint of the R2-Series’ eight outdoor units enabled them to be placed in a Burlingham Hall roof well, avoiding the space requirements of traditional, larger chiller and boiler systems. This also allowed project architects additional design space for the students’ rooms. Additionally, the system’s high-performance heat pump technology, combined with the mild temperatures of the Pacific Northwest, allowed engineers to eliminate the need for backup electric heat in each suite. Maximizing heat pump efficiency throughout the winter season helped eliminate the building’s peak electric draw on the power grid as well. The system not only exceeds local building code efficiency requirements, but its effectiveness and individual zone comfort also earned it critical USGBC LEED points in both the Energy and Atmosphere and Indoor Environmental Quality categories. The equipment’s minimal clatter from both the outdoor and indoor units and its lack of impact on the surrounding campus architecture were also significant in earning the project’s USGBC LEED Gold. Cost data analysis After the first 12 months of operation, Burlingham Hall had used 67% less heating gas than the projected baseline energy model suggested it would, expending 17% fewer therms than anticipated. “The electrical use was 33.5% fewer kWh than we modeled the baseline building to use, and the electricity (kWh) used was 28.9% less than we expected our simulated building to consume,” said Mark R. Heizer, PE, LEED AP, senior mechanical engineer for the project’s consulting engineer Interface Engineering, Portland, Ore. “This means that Burlingham Hall used $11,600 less electricity and gas than we forecasted through our energy simulation. That’s an amazing 25% less than anticipated.” Information provided by Mitsubishi Electric, HVAC Advanced Products Division, Suwanee, Ga. 52 Consulting-Specifying Engineer • SEPTEMBER 2008

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Consulting-Specifying Engineer - September 2008 Contents Viewpoint Letters News M/E�Roundtable Selecting Appropriate Egress Strategies Commissioning On-Site Electrical Systems Mentoring Control Engineers and Technicians Casting Call for Cx Case Study New Products Equipment Lifecycles Advertiser Index Green Space

Consulting-Specifying Engineer - September 2008

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