Boise State designed the Micron Business and Economics Building with sustainability at its core, incorporating geothermal heating, solar power, and a range of energy-saving and water-saving technologies. Below are the green features that make this building a model for sustainable design on campus.
Geothermal hot water heating and snow melt
The City of Boise’s geothermal hot water system heats the building with 165°F water. Using this natural resource eliminates over 90% of our building’s annual natural gas use. Heat not used to warm the building — essentially free heat — will melt snow on the main entries and courtyard.
Frictionless water-cooled chiller
Our water-cooled chiller uses magnetic bearing technology. The magnetic bearing compressors eliminate the friction of a traditional chiller, increasing the overall efficiency of the cooling system and eliminating noise. A variable frequency drive allows the system to adjust the speed of the compressors to match the building’s load without wasting energy. Magnetic bearings also eliminate the need for oil in the compressor, reducing maintenance requirements and the disposal of hazardous waste oil.
Active chilled beams
An active chilled beam induces room air through a cooling coil to temper the space. This technology shifts air delivery to more efficient water delivery systems, resulting in 75-80% fan energy savings and lowering the building’s overall energy consumption. The active chilled beams also use a warmer chilled water temperature, allowing more hours of free-cooling water-side economizer use in a typical year. Lower heated water temperatures further reduce the amount of geothermal water the building requires.
Green roof
On the wings of the building, 5,120 sq. ft. feature a green roof system. Hearty native ground cover grows in trays with 6″ of soil. The green roof reduces stormwater load on the drainage system and lowers the energy needed for heating and cooling. The living roof requires little water, is mowed once a year in the fall, and is dormant in the winter.
Solar panels
In December 2015, Boise State installed solar panels atop the Skaggs Hall of Learning (located in the Micron Business and Economics Building). The panels can produce 25 kilowatts of power per day — the equivalent of energy used by about five households.
Low-emissivity (low-E) glazing
The windows feature a thin metallic coating — low-E glazing — that increases the performance of the glass. This technology reduces energy consumption by limiting heat lost through the glass in winter and blocking up to 90% of long-wave (heat) radiation from entering the building in summer.
Building automation controls
A building automation system controls and monitors all heating, ventilating, and cooling systems and lighting in the building. The system resets temperatures during unoccupied and standby modes, adjusts the central heating and cooling plant for maximum efficiency, and uses an adaptive learning function based on weather patterns for optimal building startup. Automated lights turn on during occupied hours and turn off during unoccupied times. Classrooms, meeting rooms, conference rooms, and the lecture hall use an occupancy sensor system with a standby mode: when no one is present, the system turns off fresh air ventilation and resets the temperature by 2°F, reducing overall energy use.
High degree of natural light and energy-efficient fluorescent lighting
Modern fluorescent ballast technology and design simulation guided the placement and quantity of light fixtures, achieving a 32% savings compared to code lighting requirements. This equates to 47 kW in energy savings on lighting — enough to power three single-family homes!
Low-flow plumbing fixtures
The Micron Business and Economics Building uses low-flow plumbing fixtures throughout. This technology allows the building to use 15% less water than a traditional educational building in a typical year.
Recycled/recyclable building materials
Construction of the Micron Business and Economics Building relied on several recycling strategies: reducing, salvaging, and recycling construction waste, and using building products with recycled content. During demolition of the old University Inn, we recycled 720 tons of material. During construction, we salvaged and/or recycled 50% by weight of the total non-hazardous solid waste generated by the work. Whenever possible, we used materials with recycled content, such as the building’s structural steel and interior finishes like carpet and acoustic wall panels.
Energy recovery ventilation
Energy recovery wheels temper the ventilation air for the Micron Business and Economics Building. Exhaust air passing through the energy recovery wheel transfers up to 75% of its energy to incoming outside air, without the two air streams coming into contact. This system reduces the size of the central heating and cooling systems and lowers the building’s overall energy use.
Water-side economizer
When outdoor temperatures fall below 75° to 80°F, the building uses a free-cooling water-side economizer, which relies on evaporative cooling through the cooling tower to provide cool water for the building’s mechanical systems. When available, the water-side economizer uses 80% less energy than the building’s chiller.
Variable speed pumps/fans
The major pumps and fan systems in this building use variable frequency drives (VFDs), which adjust pump and fan speed to match the building’s load. Since a typical building operates at partial heating and cooling loads over 95% of the year, VFDs provide significant energy savings.
High-performance wall system
A high-performance wall system reduces the energy required to meet heating and cooling loads. Our building’s exterior wall system uses a cavity wall — two walls separated by an air space. Batt insulation fills the interior wall, with an additional layer of rigid insulation on the cavity side, and a fluid-applied air barrier reduces leakage. Brick, precast, and sandstone make up the exterior skin, separated from the interior wall by a 2″ air space.
Boise State has chosen not to pursue LEED certification in favor of Energy Performance Modeling design, establishing guidelines that exceed ASHRAE 90.1 and International Energy Conservation Code (IECC) energy performance criteria. We’ve chosen to meet or exceed LEED criteria while foregoing the actual certification due to certification fees.