Alaska's Sustainable Village
The University of Alaska Fairbanks takes part in the higher-education trend of efficient student housing
In the marketplace of higher education, the establishing of sustainability programs is now considered prudent, if not essential. This trend is not especially new (environmental and ecology courses boomed in the 1970s after the first Earth Day), but it has matured.
Not only have colleges and universities been the principal institutes that have researched the causes and effects of climate change and global squalor, but they have actively contributed in charting paths that might effectively address such concerns. Much of this movement has been driven by student and academic interests and initiatives. As a result, colleges and universities have learned to adapt quickly and to incorporate these initiatives into their mission statements, business strategies, and brand impact in marketing themselves.
The University of Alaska Fairbanks (UAF) has followed this trend, especially in light of Interior Alaska’s high energy costs, which are an ongoing topic of discussion throughout the state. UAF drafted its first sustainability plan in 2008. The plan was designed to implement the university’s newly created sustainable policies in nine areas: energy, the built environment, waste management, transportation, food, purchasing, social impact, institutions within the university, and education and curriculum.
In 2010, UAF formally opened its Office of Sustainability to coordinate these efforts. In 2011, the university teamed up with its on-campus tenant, the Cold Climate Housing Research Center (CCHRC), to kick-start a student housing project called Sustainable Village (SV). UAF’s administration hoped that this project would serve as the beginning of a campus-involved sustainable community.
CCHRC is a nonprofit organization focused primarily on researching, testing, and developing cold-climate building technologies that might help to meet the housing needs of people living in the circumpolar region. It is located on the university grounds, which enables it to work closely with academic departments, researchers, students, and visiting political figures. CCHRC supervised the planning and construction of the SV.
SV Student Design Competition
The university land that was chosen to site the SV had long been considered marginal land—too problematic and conceivably too expensive to build on because it was potentially unstable and unforgiving. But to the planners, such conditions were simply a continuation of the struggling contest between builders and nature that has gone on in the Subarctic and Arctic for centuries.
After the SV site was selected, the project moved to an innovative and unconventional first phase. UAF’s new model of sustainable campus housing development started with a community design. In September 2011, the university announced an open registration to a design input competition for students who wanted to participate hands-on in the SV housing project.
The winning team—which would participate in the CCHRC SV project development process—called itself Circle Vision; its members were UAF students Maura Sateriale, Garrett Evridge, Erik Williams, Lyle Axelarris, and Skye Sturm.
Phase 1: Four SV Houses
UAF broke ground on construction of the first four SV houses in early April 2012. Twenty weeks later, in September, the functional components of phase 1 were complete enough that the first students could begin moving into the houses. The four houses were named after local species of common northern trees. The southeast house on the site was named Willow; the northeast was Tamarack; the southwest was Spruce; and the northwest was Birch.
The university contracted with CCHRC, with its expertise in northern building design and techniques, to build the houses. CCHRC used a closely affiliated crew of carpenters and subcontractors as its workforce. In keeping with the core concept that building the SV was also an education outreach process, eight UAF students were given the opportunity to work alongside the skilled craftspeople and learn the latest northern construction practices.
In some respects, all the houses are similarly designed. Each house has four bedrooms, a kitchen, a living room, and a second-level, south-facing outside deck. All houses have a naturally ventilated shed-style roof filled with approximately 20 inches of blown-in cellulose with about 2 inches of air space between the insulation and the roof. All of the walls of the houses are insulated to approximately R-60 and are constructed with an exterior double-wall system to prevent thermal bridging. The exterior siding on all of the houses is a light-gauge metal wall sheathing called Nor-Clad.
Some of the materials used in the construction and on the site were from local and recycled sources. The steel pilings used for foundations on two of the houses were recycled from local military bases. Some of the exterior siding used on all of the houses was cut from salvaged water pipes that were used in gold-dredge mining during the first half of the 20th century. Paths within the village site are surfaced with wood chips made from trees that were removed from the house sites.
UAF central water and sewer services are not accessible on this part of the campus, so aboveground residential sewage treatment plant systems are connected to all houses. These self-contained systems were manufactured in Fairbanks by LifeWater Engineering. They are designed for sites where permafrost—or other soil or ground conditions—make traditional underground sewage systems unsuitable.
Each house has triple-pane, low-e windows with U-values ranging from .28 to .19 (R-3.5–R-5.2). There are induction cooking stove-ovens in each of the four kitchens. All houses have on-site potable water systems. However, two of the houses have foam-insulated water tanks located outside the house, while the other two houses have the water tanks located inside. These 1,000-gallon plastic storage water tanks are serviced by local water delivery companies (not uncommon in Fairbanks, where many houses beyond city services don’t have wells). Variances between the four houses demonstrate distinctive building characteristics and different heating systems, each designed to reduce energy demand but constructed or installed so they can be compared to one another.
TAMARACK: The Northeast House
The Tamarack house has a floor area of just over 1,510 square feet. The foundation is a system of driven steel pilings supporting steel I-beams. On top of the steel beams are 16-inch composite-wood joists with 10 inches of polyurethane spray foam insulation sprayed into each joist bay. A structural 2 x 6 wood-frame wall, with external ½-inch oriented strand board (OSB) sheathing (taped with an air-sealing tape at each seam), holds R-19 fiberglass insulation. On the exterior side of the OSB are 8 inches of rigid expanded polystyrene (EPS) insulation foam board, lapped and staggered.
The Tamarack house has a primary on-demand oil-fired Toyotomi OM 180 sealed-combustion water heater with an 87% efficiency rating. The system hydronically heats the radiant concrete floor and the domestic hot water (DHW). This primary heating system supplied nearly 90% of the heat for space and hot water during the first year of operation; it was supplemented by three 4-foot x
10-foot SunEarth solar-thermal collectors installed just below the roofline on the exterior second-story wall. The systems charge a 120-gallon storage tank.
The ventilation system in the Tamarack house is a Venmar EKO 1.5 energy recovery ventilator, which not only recovers heat from the air like a heat recovery ventilator (HRV) but also (unlike an HRV) extracts the energy embedded in humidity, increasing the energy recovery efficiency. To protect the Venmar core from freezing, the unit begins a time-controlled recirculation, cycling automatically when the temperature drops below 14˚F outside.
The 1,000-gallon water storage tank for Tamarack is foam insulated and is located outside the house, aboveground.
BIRCH: The Northwest House
The Birch house has the same floor area as Tamarack, but the foundation is different; it is an insulated mat, or raft, foundation, which provides a thermal break between the ground and the house (see Figure 1). First, a geotextile mat was laid directly on the ground and gravel was laid on top of the mat. Four-inch ABS pipes spaced 4 feet apart were buried in parallel rows under the gravel. Each end is connected to a manifold running perpendicular along the perimeter. The pipes were installed as a precautionary measure; they can function as a backup cooling conduit to help prevent house heat from transferring to the ground and disturbing any frozen soil. Before the geotextile mat and gravel were placed on the site, temperature sensors were buried about 10 feet down into the ground to monitor any heat transfer. If the monitors detect rising temperatures, cold air can be circulated through the pipe grid to cool the soil and prevent heat from disturbing the ground on which the gravel pad rests. If the insulated raft foundation works as designed, it will not be necessary to use the cooling pipes.
After the gravel pad was laid, a reinforced polyethylene sheet was placed on top of the gravel. Wood sill beams were laid parallel to each other on top of the plastic sheet, and a steel floor frame was constructed on top of the wood beams. Ten inches of soy-based polyurethane foam (Demilec) were then applied continuously in 2-inch lifts within the raised steel floor joist assembly, around the perimeter of the frame and several feet beyond it, on the slope of the plastic-covered gravel pad. Resting the uniformly-insulated steel frame on the pad is designed to keep the floor warmer than the exposed floors of the two houses built on steel piling foundations.
The wall system is similar to that of the Tamarack house. It consists of a structural 20-inch x 6-inch wood frame wall with R-19 fiberglass insulation on the interior side of the structural sheathing and 8 inches of rigid EPS insulation foam board on the exterior side. Like the Tamarack, the Birch house has an exterior-side drain wrap between the sheathing and the EPS insulation. The siding—like that of all the houses—is primarily Nor-Clad corrugated metal sheathing with a small percentage of salvaged steel from local inactive dredge mining sites.
The primary heating system, however, is unique. It is called BrHEAThe, and it was developed by CCHRC. In this system, a Webasto diesel-fueled heater—the Air Top Evo 5500, an inline, sealed-combustion unit normally used as a truck cab heater—is integrated with an HRV to maximize energy use while maintaining healthy indoor air quality (IAQ). The Webasto heater is one of many automotive products manufactured by the Webasto Group, located near Munich, Germany. It is rated at 17,500 Btu/hr.
The Webasto heater warms the supply air into the Zehnder ComfoAir 350 HRV system. The HRV has a maximum capacity of 215 CFM, is certified by the Passive House Institute at 84% efficiency, and delivers the warmed fresh air throughout the house. The HRV has an 800W electric preheater, which activates to protect the core from freezing when the outside air temperature drops below 15˚F. If this fails to keep the core from freezing, the unit controller will begin reducing the supply air while maintaining the exhaust flow.
The house also has a Summers Heat 55-SHP 10 pellet stove made by England’s Stove Works as a secondary heating system. A 20-gallon Marathon electric water heater produces the DHW.
WILLOW: The Southeast House
The Willow house has the same foundation as the Tamarack house and the same wall and siding configuration as both Tamarack and Birch, but its floor area is about 1,720 square feet. Unlike the Tamarack and Birch houses, which have their domestic insulated water storage tanks outside the conditioned space, the Willow house makes room for the 1,000-gallon water tank inside, which might account for the additional 210 square feet of floor area, This floor area is needed to support an extra 8,340 lb of internal weight when the water storage tanks are full.
The Willow house, like the Tamarack, has a radiant floor to distribute the space heating. The primary heating system is an HTP Phoenix propane-fired condensing water heater, which is marketed as up to 96% efficient and is capable of connecting to radiant heating. This system supplied over 88% of the space and water heating during the first year of operation; it was supplemented by three 4-foot x 10-foot SunEarth solar-thermal collectors. Unlike the Tamarack house, however, the Willow house has a Venmar EKO 1.5 HRV, which only recovers heat from the air. This was another example of comparing different technologies in different houses.
SPRUCE: The Southwest House
The wall construction of the Spruce house is different from that of the other three houses. The interior structural wall is similar to that of the other three houses; it consists of 2-inch x 6-inch studs with an exterior-side plywood sheathing, which was taped and air sealed. Outside this structural wood wall, a steel nonstructural frame is attached with plywood gussets extending out from the interior wall. An air barrier was wrapped around the exterior side of this wall. The cavity between the structural wood and the nonstructural steel walls is approximately 12 inches deep. It was filled from the interior with dense-pack cellulose insulation through 6-inch holes in the sheathing. The insulation was blown into each wall bay before the R-19 fiberglass insulation was installed. The holes in the sheathing were closed with a polyethylene patch affixed with an acoustical sealant. The total thickness of the wall is about 18 inches.
The Spruce house has the same floor area as Willow, and the same internal 1,000-gallon plastic water storage tank. The Spruce house has a raft foundation like that of the Birch house, and a BrHEAThe heating system, which creates heat through a Webasto diesel-fueled truck cab heater and distributes air through a Venmar EKO 1.5 HRV. It also has a 20-gallon Marathon electric water heater.
The Spruce house also has a Steffes electric thermal storage (ETS) room unit heater. Using this heater could be extremely expensive, since neither Fairbanks nor UAF has preferential electric rates for off-peak, time-of-use, demand, or smart metering, and the cost of electricity in Interior Alaska is among the highest in the country. However, according to CCHRC, another energy research center at UAF focused on investigating alternatives to Alaska’s high energy costs is using the ETS unit in the simulated storing of excess wind energy from data collected in a rural wind generation project.
Monitoring Performance of the Houses
Embedded within the site and throughout the houses are sensors and meters wired to collect data and track performance, though not all of these data have been published yet. As of this writing, published data consist of reports on fuel, electricity, and IAQ. The houses’ designed heating estimates projected that energy consumption would be about 27 million Btu/yr, or the equivalent of 200 gallons of heating oil. First-year totals for the four houses averaged about 400 gallons, but this was the first year, winter, and first occupants.
An IAQ report on the houses was released in 2013. Data collected during a two-week period in December 2012 showed significant differences in IAQ among the four houses. These differences appeared to be related to occupant behavior, or to control settings on the HRVs. System adjustments on controlling the HRVs, particularly during periods when the units went into frost protection mode, and occupant education were recommended to improve the indoor air. During the survey period, only one house was within the hourly average fresh-air supply rated to meet ASHRAE 62.2 recommendations; none of the houses met the higher recommended ventilation rates set by the State of Alaska.
Electricity use in each house, as might be expected, also varied. First-year SV student residents Clayton Auld and Megan Younger initiated a project to collect electricity use data using a WattNode Modbus, a kWh energy and power meter that communicates on a point-to-point network measuring power directly from the conductors entering each building via connected current transformers. Data collected from the utility electric meter showed that yearly consumption varied from about 9,400 kWh in a high-use house to nearly 4,300 kWh in a low-use house.
Another lesson learned from the raft foundation was that spraying polyurethane foam on top of the reinforced polyethylene sheathing did not work well. Monitoring of sustainable social and lifestyle practices, such as composting, recycling, or gardening, has yet to be reported.
Build, and Sustainability Will Follow?
As is true of many trends that are well orchestrated in marketing, the details of coordinating, operating, and nurturing sustainable practices throughout the university environment are often not as well thought out as the technical specifications in a building design. UAF did not follow up on its original plan to have students apply specifically for SV residency, and to agree to sustainability commitments and guidelines. That plan was dropped. When asked, several SV residents said they had friends on campus who either had not heard of the village or did not know where it was located. Outreach to other institutions within the university was lacking. The SV housing quickly became listed as just another residence option for any student who chose to live there, regardless of his or her commitment to the tenets of sustainability.
However, most of the students who occupy the SV housing are enthusiastic about the concept, despite initial start-up quirks that left some students feeling a little abandoned and not part of the living laboratory that was advertised. There is little question that the UAF SV houses constructed by CCHRC were built to be efficient, using northern building methods and technologies that could maximize energy and water use—but will buildings alone foster a sustainable community or village?
For more information on the Sustainable Village, visit www.uaf.edu/sustainability/sustainable-village.
Sustainability is often presented piecemeal, without a cohesive follow-up plan. Laying out a garden site, a bike path, a solar array, a village site, or building an efficient house is the easiest part of the sustainability plan, but it may not create a sustainable village if we ignore the human component. Trending universities may be left with a new architecture of buildings but not necessarily a rising new standard of living going forward. The students are the ones who ultimately inhabit the UAF SV and whose experience will either be carried forward through that experience or simply end there. We hope that UAF, and all universities that initiate green lifestyles for their students, will integrate this new housing into a complete and coordinated campus-wide crusade.
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