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Textbook Tech

April 23, 2007
Green educates, green performs at Oregon school

By Chelsea Houy

It didn't have a name. No one was sure what it would look like. They simply called it the "new elementary school." But, despite its lackluster label, architects and school officials knew this school would be anything but typical - more than just walls, windows, and whiteboards. Design would be sustainability's student. Building technology would teach.

Taking it to the Next Level
It was 2004, and construction was under way at New Columbia, an 82-acre housing development in North Portland, OR. Built on the former site of Columbia Villa, a housing project built in 1942 for World War II defense workers, it would have twice the units of its predecessor. In just one short year, families would move in. Of concern to Portland Public Schools (PPS) officials was how to accommodate an influx of new students into two existing neighborhood schools - Ball Elementary and Clarendon Elementary - neither of which had the necessary capacity. At Ball, a deteriorating building structure compounded the issue. A new school was needed, but the district had little capital for construction.

PPS and the Housing Authority of Portland were joined by architects and Portland Parks and Recreation to investigate several options. Out of their collaboration emerged the "community campus" concept. The campus would consist of a new Boys and Girls Club, a remodeled/renovated community center, and a new school, which would eventually be known as Rosa Parks School. Each facility would include shared spaces and offer services to students, their parents, and the community, and, by doing so, reduce the total project cost.

The shape of Rosa Parks School was ultimately dictated by its surroundings as it meanders northward through maple, cherry, and oak trees on the property. Its low-impact, single-loaded corridor design yields to the landscape.

With the exception of Forest Park Elementary, built 10 years earlier, this school would be the first built by PPS in 30 years. "[PPS officials] wanted to use this particular project to create a vision of what they wanted schools of the future to be," says John Weekes, AIA, principal at Portland, OR-based architectural firm Dull Olson Weekes Architects (DOWA). The firm would design the school as well as the Boys and Girls Club and the community center renovations.

From the beginning sustainability was the golden rule. "Portland Public Schools really view themselves as the stewards of the children and their future," explains Karina Ruiz, AIA, project manager, DOWA.

School officials not only wanted the facility to be an example of the wise use of natural resources but also a living lab for students, where they could learn the ABCs of environmental responsibility. Rosa Parks School is environmental stewardship designed to the next level.

Looks can be deceiving. Although this may appear to be just a water feature, it is actually a bioswale. The system filters storm water collected from the roof and paved surfaces on the school grounds, ultimately distributing it back to the water table through 30-foot-deep drywells.

Filtration Education
Located on a narrow site west of the community center and south of the Boys and Girls Club, the school's shape responds to the landscape: Purposely meandering northward through maple, cherry, and oak trees, gradually curving west, bending into what looks like an upside down J, its low-impact, single-loaded corridor design yields to the landscape.

There is what appears to be a small stream. In fact, it's a water filtration system, one of five bioswales located on the school grounds. It's also an educational tool for the 480 kindergarten through sixth-grade students currently attending Rosa Parks School. Many of the sustainable features both inside and outside of the building are designed in a way that the children can interface with them. "It becomes part of the curriculum as well," remarks Weekes.

Rainwater collected on the roof and several paved surfaces around the school is carried through a series of drains to the bioswales. A special combination of plants and soil mix filters pollutants out of the water. From there, the water travels through another set of pipes to a sedimentation manhole: Sediment falls to the bottom and "cleaner" water is piped to one of three 30-foot-deep drywells and distributed back into the water table. "No storm water leaves the site into the city storm system," says Weekes.

There were talks about using the bioswales as part of a graywater collection system for either landscaping or flushing toilets, explains Weekes, but due to site and financial limitations the idea was tabled. Instead, drought-tolerant plants, which require 50-percent-less irrigation than traditional choices, are scattered throughout school grounds. Inside the school, plumbing fixtures also aid in H2O conservation. Urinals operate on a 10-minute delay tied to an occupancy sensor, while toilets are equipped with Sloan Royal Model 111 Flushometers. Bathroom sinks have metered faucets that turn off automatically.

Lighting Enlightens
With classrooms lining only one side of the main corridor in the two-story, 45,147-square-foot school, designers could daylight classrooms from the east and west.

Interior windows allow daylight to penetrate rooms from more than one direction.

Butt-glazed relites fitted into classroom walls facing the corridor allow classrooms to receive daylight filtering into the corridor or "commons," as it is called by staff and students. The relite is essentially a frameless interior window. The glass fits into channels at the top and bottom of the window, but the side seams of the glass are sealed together, creating the appearance of a continuous pane.

Although trees shade portions of the school during the spring and summer months, site constraints had placed the building on a north-south axis; with an east-west exposure, additional measures were needed to harness daylight and control heat gain into classrooms and the corridor, which face east and west, respectively. (Because the sun is at a lower angle in the sky in the Northwest, placing a building on an east-west axis is ideal to reduce heat gain in the summer and maximize heat gain in the winter.)

On the east side, custom-made light shelves and horizontal sunscreens steer the morning sun into classrooms. On the west side, where the school needs the most protection, vertical sunscreens with Kawneer airfoils (louvers) combine with the natural shading of the trees to deter the intense afternoon sun. PPG Solarban 60 Clear double-glazed low-E glass with winter u-values of .29 and shading coefficients of .44 offer additional protection to classrooms and offices.

Inside classrooms, light level sensors adjacent to exterior-facing windows turn off the nearest bank of fixtures when daylight exceeds 150 percent of artificial lighting levels; occupancy sensors control the remaining fixtures.

On the flip side, a two-zone lighting control system, designed by Portland-based Reyes Engineering, supplements daylight harvesting in classrooms. Watt Stopper LS-100 light level sensors, adjacent to the windows, turn off the nearest bank of fixtures when daylight exceeds 150 percent of artificial lighting levels. Peerlite Cerra 7 T5HO pendant fixtures emit 5 percent direct and 95 percent indirect lighting, which is effective in creating even illumination, eliminating the "cave effect."

Watt Stopper CX-100 and WA-200 occupancy sensors control remaining fixtures in classrooms as well as those in conference rooms, staff and work rooms, offices, and the Family Resource Room.

A demonstration photovoltaic system was provided by the Bonneville Environmental Foundation’s "Solar 4R Schools" program. Six panels located on the south side of the Media Center generate between 65 and 100 watts.

According to Principal Tamala Newsome, teachers have created lessons to educate students on the lighting control system as well as the demonstration photovoltaic (PV) system. The PV system was installed as part of the Bonneville Environmental Foundation's "Solar 4R Schools" program. Six PV panels located on the south side of the Media Center generate between 65 and 100 watts. A wall-mounted flat screen monitor at the entrance provides real-time data about the system's electric-power production. Teachers use curriculum developed by BEF to teach students about solar electricity.

Currently PPS purchases 100-percent renewable power in the form of "clean wind" from Portland General Electric (PGE). A preliminary energy model estimated the amount of electricity the school would consume; then PPS contracted with PGE to purchase so many kilowatt hours of the "clean wind" power, which will sustain the school's electrical needs for a year. According to PPS Energy Specialist Catherine Diviney, Rosa Parks is the first school in the district to purchase this type of "green" power.

Old School IAQ
Displacement ventilation has been around for years but is being reintroduced as an alternative to overhead ventilation systems, says Karl Atteberry, PE, LEED AP, principal of Portland-based Mazzetti & Associates. Atteberry was the mechanical engineer on the Rosa Parks project.

Unlike an overhead system, which supplies and returns air from the ceiling, displacement ventilation ductwork supplies air at ground level. Air comes out of two 30-inch-wide by 5-foot-tall grilles located in each classroom. Air crosses the room and fills up the volume at lower levels first. As the air hits a warm object such as a child or computer, it creates a thermal plume. The plume rises to the return air system in the ceiling and is directed to a rooftop air-handling unit. Some of the air is exhausted, and the rest is mixed with outside air, filtered, and recirculated. "It creates a very uniform temperature within the space; there are no drafts and it also minimizes the intermixing of air between students," says Atteberry.

Because the air is introduced at floor level, occupants receive more fresh air in the breathing zone, which is between 3 and 6 feet - depending on whether a person is sitting or standing. In an overhead system, much of the fresh air is mixed above the breathing zone and turns back to the return system before reaching occupants. In displacement ventilation all fresh air is used, filling the space from floor to ceiling and pushing contaminants out the room - good news to any parent who has had to pull a sick child out of school because he or she has caught the latest bug.

Another advantage of displacement ventilation: The velocity in the ductwork is substantially slower than an overhead system. "The static pressure of the energy required to move the air is a lot less, so it uses much less horsepower than a traditional system. From a sustainable standpoint you also get that savings," says Atteberry.

The one disadvantage of displacement ventilation, adds Atteberry, is that some floor space is taken by the ductwork and grilles. DOWA architects incorporated the components into cabinetry for the classrooms for a more pleasing appearance.

Data from the demonstration photovoltaic system displays on a wall-mounted flat screen monitor at the entrance of the school. An adjacent monitor displays school announcements.

With Honors
Although the school just opened last September after a break-neck 10-month construction schedule, which concluded a month earlier, it is already receiving accolades. It was one of two educational facilities selected by the American Institute of Architects to be presented at the Union of International Architects' International Conference on Education. The school also received a sustainability award from the Oregon Department of Energy at the school's dedication ceremony. According to energy models, the community campus will be 29-percent more efficient than Oregon Energy code requires. Until the Boys and Girls Club is completed this spring, however, the design team anxiously awaits the numbers.

For now, they take pride in the fact that the total project cost was cut in half as a result of the project's partnerships. "At the time we were thinking it could be close to $30 to $35 million. By sharing space and working together, it was a $17 million project," says Weekes.

When all is said and done, for the design team, this project was about doing the right thing; producing something that was beneficial to the environment and to the community. Like Rosa Parks, a courageous woman who stood against an establishment by refusing to give up her seat in a bus in 1955, Rosa Parks School stands for what is right, both figuratively and literally, and it passes that spirit onto students through its interactive, environmentally friendly design.

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