Buildings that Perform

Designing the environment

May 25, 2009 – Imagine cutting the energy consumed by a building to less than half of what’s required to meet the efficiency standards for new buildings. That feat is becoming routine for James Love, an NSERC-funded architecture professor in the University of Calgary’s Faculty of Environmental Design and holder of the university’s Chair in Sustainable Building Technologies. Using the latest designs and technology for heating and ventilation, he helps design buildings with vastly improved environmental performance.

Once constructed, those buildings become live experiments, as Dr. Love and his team monitor performance to see how the design works out under real-world conditions. That data, combined with computer simulation studies, helps refine their approach so the next building does even better.

The results are impressive. His first design for a school, completed in 2000, was found by Natural Resources Canada to be 25 percent more energy efficient than the average building. In 2002, he designed systems for the Foothills Advocacy in Motion Society building in High River, Alberta, that proved to be 64 percent more efficient. And his 2005 design for Alberta’s Vulcan Prairieview Elementary School exceeded the standards by 57 percent.

"Building operations account for about 30 percent of Canada’s CO₂ emissions," says Dr. Love. "New approaches in commercial building systems can substantially reduce this."

The technology he uses to achieve high levels of efficiency includes radiant slabs with pipes embedded in them that circulate hot or cold water depending on the need for heating or cooling. He combines that with "displacement" ventilation systems, which feature air coming out of the lower part of the wall instead of from the ceiling. Displacement ventilation takes advantage of hot air’s natural tendency to rise, reducing the fan power required to circulate air. The stratification also improves removal of airborne contaminants.

Since completion of Prairieview school, extensive instrumentation has been installed to evaluate performance in terms of thermal comfort, ventilation effectiveness and energy use. Results to date indicate that the school uses about one-third of the energy per square metre compared to the average Alberta school.

One of Dr. Love’s more recent experiments is right on campus. The University of Calgary’s Child Development Centre (CDC), which opened in 2007, provides the opportunity to field test displacement ventilation and underfloor air distribution systems. The building also features the largest photovoltaic array in Western Canada.

"The Child Development Centre is a big experiment based on a hypothesis about more sustainable environmental control," says Love. "We measure various characteristics of the building, including ventilation effectiveness. Lab studies have shown that displacement is more effective than overhead supply."

The building was among the first in Canada to earn the top-level Platinum certification under the LEED (Leadership in Energy and Environmental Design) rating system. For the university, it was the beginning of a commitment that targets the same performance for every new building built on campus.

The 12,000 m² CDC is also pivotal in the study of underfloor air distribution, another technology with hardly any field research reported to date. As more data comes in, Dr. Love hopes to continue raising the bar in building design and operation by demonstrating leading edge practices and making them more affordable.