Meeting IAQ Guidelines

• By Richard Parrish
• 11/01/07

Tim Cadotte has been in his newly built office about four years and occasionally likes gazing out his windows at the beautiful Minneapolis neighborhood or watching a plane fly low overhead on approach to the airport. He also likes watching parents drive up outside his office to let their kids off at the front entrance.

But he sure doesn’t miss the deafening roar of jet aircraft flying over constantly or the street noise and other outside racket that used to permeate his office and the rest of Burroughs Community School. He also doesn’t worry about students breathing fresh air because the school was the first to meet the Minneapolis Public School’s (MSP) new guidelines for both indoor air quality (IAQ) and acoustics. Both guidelines have since been adopted statewide.

Another plus is the fact that the school’s 45 teachers are easily heard in the back of their classrooms without raising and straining their voices. However, if outside noise is minimal, they can open windows for fresh air, just like schools of a bygone era. Even more impressive, the completely redesigned and rebuilt $17M Burroughs Community School is operating nicely on 30 percent less energy than the structure it replaced.

These and many other benefits stem from sustainable architectural concepts that were used by Minneapolis-based Kodet Architectural Group, Ltd. to create an innovative design for the school, which opened in the fall of 2003. It’s the kind of building report card that school officials, educators, and taxpayers like to see.

An important consideration early on was the footprint for the new structure, which MPS wanted on its own five-acre site. Adjacent green space owned by the Minneapolis Park Board lies between MPS’ property and Minnehaha Creek.

The smaller amount of land on which to build the school, coupled with all the other needs expressed by people involved in the planning process, meant adding height, instead of length or width. As a result, the new Burroughs school would become three stories high, instead of two, as was its predecessor.

Keeping Everything Fresh & Green

Kodet’s team used established guidelines for introducing sustainability into a public school, including those from the State of Minnesota and LEED, the Leadership in Energy and Environmental Design Green Building Rating System. As mentioned, Burroughs was also designed and constructed to meet MSP guidelines for IAQ and acoustics in school construction, which were adopted in 1997 and 2001, respectively.

The Kodet firm participated in two separate task forces, along with representatives from the University of Minnesota and other prominent architectural, engineering, construction, and manufacturing companies, that developed each set of comprehensive guidelines. They stipulate compliance standards and procedures for building or remodeling a school, including early planning, site preparation, construction, post-construction, commissioning, and ongoing monitoring and maintenance.

MSP’s IAQ guidelines focus strongly on air filtration and ventilation, humidity controls, protecting ductwork, and eliminating off-gassing of volatile organic contaminants. VOCs, as they are called, are often residual byproducts of producing materials, such as paint, adhesives, finishes, plastics, and carpeting. Besides stipulating“General Requirements” and“Sitework,” the 20-page document details specifications, handling, and installation of concrete, masonry, metals, wood and plastics, thermal and moisture protection, doors and windows, finishes, specialties, furnishings, and mechanical and air handling systems.

Beginning with the construction phase itself, the Kodet Architectural Group required contractors to cover all ductwork and chases to prevent dust, moisture, mold, and other VOCs from getting into them. High-efficiency ventilation equipment for the school’s IAQ system provides enhanced capacity and additional filtered fresh air, as required by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). The air intake system in the school’s attic supplies 100 percent outside air to classrooms, and provides approximately 35 percent humidification in winter, and 60 percent dehumidification in summer.

In keeping with sustainable practice, the new school was constructed with materials that could be recycled when the building reaches the end of its useful life. “We looked at the recycled content in countertops and literally everything in the building,” Kodet said.

Steel studs were used, which are about 90 percent recyclable, along with “green” label carpeting that emits very little, if any, VOCs. In addition, contractors could only use paint that was designated low-VOC and wood products that did not contain any formaldehyde.

A Sound Beginning

Sustainable architectural design for acoustics in classrooms at Burroughs was also extensive. “We know how well students hear in the classroom is vital to their learning ability,” Kodet said. “Excessive noise and reverberation in the classroom make speech difficult to understand. We also know that better acoustics help younger students, especially those with learning or auditory processing difficulties, and those who speak English as a second language.”

Kodet’s architects considered all the materials and shapes of a classroom, including the walls, ceilings, floors, and windows. As a result, the footprints for a number of classrooms at Burroughs are trapezoidal with the front of the room about twice as wide as the rear. Non-parallel walls and ceilings that sloped from front to rear all help direct sound to the back and reduces reverberation to between .6 and 1.6 of a second.

Ceilings are constructed of special sound-absorbing tiles. In addition, inside walls are thicker and filled with insulation, especially where they separate a classroom from noisy public areas, such as hallways and stairwells.

“Having been a teacher myself for a number of years,” Cadotte said, “I know what it’s like to continually raise your voice in a classroom, so all the kids could hear me. Sometimes I had to shout. But here, teachers can talk in a normal tone of voice and everyone in the room can hear them.”

Approximately 750 students from kindergarten through fifth grade enrolled this fall at Burroughs, which is now at capacity, according to Cadotte. The facility provides nearly 94,000 sq. ft. of space for classrooms, a gymnasium, a small auditorium, and a lunchroom.

Named after John Burroughs (1837-1921), a naturalist and popular writer who became known as the Grand Old Man of Nature, the new school replaces a 74-year-old building in south Minneapolis that had been added to several times. Demolition, site prep, and new construction took about a year, during which time students were bussed to a temporary school.

This fall will mark the beginning of Cadotte’s ninth year as principal of Burroughs and his 26th year with Minneapolis Public Schools. “When I first came to Burroughs, the building was in very bad and neglected condition,” Cadotte said. “It was a neighborhood school, yet the neighborhood wasn’t choosing to go to the school.”

During the next few years, he began meeting with parents and community groups to promote enrollment. Things turned around. Academics and test scores improved. More parents began bringing their children to the school.

Time to Take Action

Although he was effective in increasing enrollment, many parents said something had to be done about the aging building itself, which was actually sinking because it was built on wood piling over the nearby creek’s flood plain. Through time, ground moisture caused the piling to deteriorate.

Cadotte met with the MSP school superintendent to see what could be done, which led to meetings with groups of parents, neighbors, residents, and others to organize a site committee. A turning point came in 2000 at a school open house for the school board, city council, parents, and neighborhood residents. They saw first hand how much the building had fallen into disrepair despite repeated fix-ups.

“People shook their heads in disbelief,” Cadotte remembered. The next year, the school board concluded the only way to remedy the situation was to build an all-new building on the same site.

Following their decision, activity on the project gathered momentum rapidly. A facilities committee was formed, including Cadotte, other school officials, parents, neighbors, and others. Request for Proposals (RFPs) were sent to architectural firms, including Kodet Architectural Group, Ltd.

Kodet received the nod primarily because of its leadership in helping develop IAQ for MSP experience and its experience in the 1990s with design projects for three other Minneapolis schools, including one with the new IAQ standards. A major goal for the firm’s sustainable design for Burroughs was to reduce all energy consumption by 30 percent with high-efficiency, on-demand systems for lighting, heating, air conditioning, and ventilation.

Illuminating a New Era

An example is the pervasive use of daylighting with oversize, eight-ft.-high H-windows on outside walls that bathe classrooms in natural light. The double-glazed laminated windows also provide insulation and mitigate outside noise.

Clerestory windows in many rooms, including the lobby and gymnasium, provide more natural lighting. In addition, all rooms are equipped with occupancy sensors that automatically turn lights on and off when needed.

“Kids need good lighting for brain stimulation,” Cadotte said. “What people often think of as luxuries are optimal conditions that promote better learning for kids. Other examples are good ventilation and air conditioning because kids simply do not function well in hot, stuffy rooms. It’s not healthy and makes them sleepy.”

“But where we really achieved significant energy savings was with the use of high efficiency furnaces and gas-fired boilers,” Kodet said. In addition, a heat recovery system in the school’s attic captures reusable heat, and air is transferred from the cafeteria to the kitchen to reduce its make-up air requirements.

Thermostat controls automatically heat or cool classrooms and other areas to pre-set levels in advance of people occupying them. However, individual controls in each classroom allow the teacher to adjust the temperature.

“Sustainable guidelines also include natural ventilation,” Kodet explained, “so all the classrooms have operating windows. If it’s a beautiful spring or fall day, the school can literally shut the system down and teachers can open windows to provide natural ventilation.” There are also variable air volume controls in a number of areas of the building.

Another major plus from the new construction is that the building will remain solidly in place, thanks to more than 400 steel piles that were driven deep into the ground. The school was built on top of the piles and rests above a four-ft. crawl space that will accommodate a high water table or a 500-year flood from the creek. As a result, there is no basement, so all the utilities and mechanical equipment were located on the third floor or in the attic.

The final step of the sustainable architectural design for Burroughs was to fully commission the new building. This involved monitoring construction to assure that it was built according to design specifications and that all operating systems were installed and functioning properly. After 10 months, the building and operating systems were checked once again to make sure everything was performing in accordance with design specifications.

Richard Parrish is president of MindShare Communications. He can be reached at [email protected] or 952/449-9997.