Turnbull National Wildlife Refuge - Inland Northwest Complex Headquarters
Fish and Wildlife Service, Washington
Project Point of Contact
This super-insulated high performance facility is a model of sustainable design. The building was constructed using stone from a regional quarry, and includes a cool roof; daylighting; low-e glazed windows; efficient LED lighting; occupancy sensors; and a 14-ton geothermal heat pump, resulting in energy performance 32 percent better than an average building. A 4.9-kW grid-tied solar PV array produces electricity; and domestic hot water is provided by a roof-mounted solar collector system. The 15.5 MWh of renewable power generated saves 10 metric tons of GHG emissions annually. Inside, low-VOC carpets, paints, and adhesives provide a healthy work environment. Outside, landscaping with native plants and bioswales reduce runoff. On June 10, 2010, Greening America, DOE's Federal Energy Management Program selected this project for recognition as part of their "You Have the Power" campaign.
A highly collaborative, integrated planning and design process guided by an integrated design team developed the 6,957 square-foot high performance Inland Northwest National Wildlife Refuge Complex Headquarters building as a model of sustainable, integrated design. The team made provision to ensure incorporation of these goals throughout the design and lifecycle of the building, including deconstruction. Care was taken to ensure that the building complies with the Guiding Principles for Sustainable New Construction.
Passive solar energy strategies were emphasized. Examples include: building orientation, thermal mass, superinsulation, daylighting, and energy-efficient windows. The long axis of the building faces south for generous exposure to light and warmth of natural sunlight. The concrete and exterior stone masonry from a regional quarry provides thermal mass to help maintain a comfortable indoor air temperature and reduce the demand for commercial power.
The superinsulated building envelope has: a concrete slab-on-grade floor with 2 inches (R10) of rigid insulation over a black poly vapor barrier below and 1.5 inches (R7.5) in the edges around the perimeter. Reinforcing steel and concrete was placed above the insulation. The floor absorbs solar heat during the day and radiates it back into the rooms at night. Spray-applied expansive-foam insulation completely fills the voids in the stick-built 2x6 walls to an insulating value of approximately R40 with resulting low fenestration and associated energy demand.
Daylighting is abundant. In plan view, the interior doors and tall, narrow side windows are located opposite the exterior windows to provide a bright, cheery building interior with minimal need to turn on the room lights. The windows are triple-glazed (3 panes of glass), argon gas filled, with low-e (emissivity) coating that have an insulating value of R4 (U 0.25), which is 30 percent more energy efficient than traditional thermal (double) pane windows. Light bronze tint on the south and west windows reduces glare and summer heat gain. Windows and insulation are virtually maintenance free and cost effective. The building is heated and cooled via a combination ground-source heat pump with an overhead electric forced air system. To heat the building in the winter, heat is extracted from the ground. To cool the building in the summer, heat is deposited back into the ground (the system can do both at the same time). Heat energy is exchanged with the ground (that has a near constant year-round temperature of about 50 degrees F) by a methanol-water brine that circulates through a total of 17 loops, each 800 feet long (round trip), of 0.75-inch diameter, black high density polyethylene (HDPE) pipe spaced 4 to 7-inches apart and buried at a depth of 5 feet. The total cooling capacity of the GSHP is 172.2 MBH, or 14.35 tons. Water is used in the geo-field ground loops because it has high heat carrying capacity, and methanol is added to help prevent freezing, allowing the use of relatively small pumps and compressors; which also saves energy.
Commercial electricity is supplemented with 4.9-kW grid-tied (net metered) solar photovoltaic array that produces about 5.9 MWH of AC electricity annually, converted from DC power by an inverter. Per-module monitoring and analysis of the performance of the solar PV array is tracked using the Enlighten system by Enphase Energy. Domestic hot water is provided via a dual-tank solar-thermal system with electric backup. The 54 square foot flat-plate roof-mount collector heats a 92-gallon water tank ahead of a 67-gallon water tank. The tanks are purposely oversized to function as heat reservoirs and are located near the center of the building. The demand of hot water in this building is relatively low, and consequently the system provides virtually all of the domestic hot water needs year-round.
Results and Achievements
The building is at least 30 percent more efficient than ASHRAE 90.1-2007 standards. Lights are energy efficient T-8 fluorescent tubes with electronic ballasts. In addition, LED (Light Emitting Diode) lights are used in EXIT signs, and in can lights above the conference room cabinets. Occupancy sensor switches turn off interior lights in unoccupied rooms. All kitchen appliances are ENERGY STAR® rated. Assuming an ENERGY STAR® rating of 80, the building uses 32 percent less energy than an average building for a total annual energy cost savings of at least $1,680.
Including the GSHP, the total energy generated by renewable energy is 15.5 MWH, or 52.7 million BTU. Both solar systems together would generate 7.5 MWH, or 25.6 million BTU.
All plumbing fixtures such as urinals and toilets are WaterSense low water use. The cost of the water conservation features of the project are included in the total project cost and were not identified separately. No garbage disposal is used; kitchen waste is thrown away; rather than using water and electricity to grind it into liquid waste. Gray water and domestic sewage are treated by an on-site septic drain field. Surface water from the parking lot flows to bioswales planted with mix of native grass and shrubs.
Where feasible, buildings, parking areas, and utilities were located in pre-disturbed land areas, minimizing removal of trees and shrubs. Native and established non-native plant species conifers were protected as much as possible during construction. The existing house that once stood on the site was demolished, and many non-native trees and shrubs were removed. Disturbed areas were restored to a grassy, meadow/prairie like condition. The area has been planted with native plantings, grasses, and forbes. Grass seed mix is Festuca idahoensis, bluebunch wheatgrass Agropyron spicatum, and rhizomatous slender wheatgrass Agropyron trachycaulum.
During construction, more than 50 percent of the construction waste was diverted from landfills. The office building is equivalent to a Leadership in Energy and Environmental Design (LEED) Silver rating. It is sided with Hardie Plank siding. The exterior wainscot is rock from a regional quarry. The standing-seam weathered copper-colored metal roofing (used instead of composition shingles), which was selected to protect the building from wildfires, meets the ENERGY STAR® Cool Roof reflectivity criteria. All reinforcing steel rebar has a high (60 to 90 percent) recycled steel content. Interior doors are Lynden Greencor Agrifiber with real wood veneer. Low VOC carpets, paints, and adhesives were specified to improve indoor air quality.
Greenhouse gas savings vary depending on the model used. Approximately 4,676 pounds of CO2, 119 pounds of SO2, and 56 pounds of NOx air pollution emissions would be reduced. Other estimates using OMB and ENERGY STAR® factors show 10 to 12 metric tons of CO2 would be saved annually. Plastic, glass, metal, and paper products are sorted into recycle bins for transport to the recycling center. An estimated 360 pounds of waste are avoided annually.
This facility provides a basis for development of similar projects at other National Wildlife Refuges. Once other Service engineers and staffs learn how successful this project has been, they will be more inclined to incorporate these technologies in the specifications and construction documents for similar projects in their Region. In addition, the Service's Strategic Climate Change Plan calls for achievement of carbon neutrality by 2020. This project has already been used as an example of sustainability in a presentation by the Service Energy Coordinator at a recent Department of the Interior Conference on the Environment in Portland, Oregon. The use of emerging renewable energy technology meets the Service's Climate Change action goals.
A large coalition helped the project to come to fruition and achieve effective results. The original design for the project was the result of a design team comprised of the Service, Northern Management Services, Inc., Calvin Jordan Associates, Inc. (Architectural), J-U-B Engineers (Civil), Michael Tagles (Mechanical Engineering), Garry D. Moore, AIA (Electrical), and Meulink Engineering Inc. (Value Engineering). In addition, valuable input was provided by the Friends of the Turnbull Refuge.
A varied combination of strategies achieved more efficient results: this project is one of the leaders in the wave of forthcoming new projects that will include energy efficiency and multiple renewable energy technologies (such as both solar PV and solar hot water).