Arguably, no large building in the world better exemplifies the bioclimatic design principle of putting architecture to work to keep occupants comfortable and minimize loads on the mechanical system. With its solar chimney, reversed double-wall facade (double glazing at the exterior instead of the interior), and six-story passive solar winter gardens, the 18-story Manitoba Hydro Place (GreenSource, March 2010) tames Winnipeg's frigid but sunny winters and hot summers.
Location Winnipeg, Canada (Lake Winnipeg Watershed)
Gross area 695,742 ft2 (64,634 m2)
Cost $271 million
Annual purchased energy use (2011-12) 56 kBtu/ft2 (631 MJ/m2), 42% reduction from base
Annual carbon footprint (predicted) 1.8 lbs. CO2/ft2 (8.9 kg CO2/m2)
TEAM & SOURCES
MASONRY: Alpha Masonry
METAL/GLASS CURTAINWALL: Ferguson Neudorf Glass
EXTERIOR DETAIL AND INTERIOR GLASS PARTITIONS: Border Glass & Aluminum
Getting all the systems integrated was no mean feat, however. During its first winter, both the boilers and the heat pumps were working more than twice as hard as the models predicted (see graph), and occupants weren't proactive about opening their windows. Spurred in part by the promise of a $1 million bonus for achieving the project's energy goals, the design team worked with Manitoba Hydro's engineers in commissioning and fine-tuning the operations of the building for a full year after it opened. Much of that process involved figuring out how the systems were actually working, then adjusting control settings to improve their efficiency. The team used smoke tests to learn, for example, that air in the double-wall plenum was not mixing as they expected, so when occupants opened their windows they were getting outside air directly. This allowed the team to increase the hours during which the building operates in natural-ventilation mode to an annual average of 35 percent.
Three years after the building was occupied, the design team reconvened. "We met for a day and went over the entire project, warts and all, to see what we have learned from the process and design elements," reports Manitoba Hydro's Tom Akerstream. One key lesson: in retrospect, "we would want to have taken the double-wall buffer zone around the entire building," says architect Bruce Kuwabara. "This would have buffered the southern tips of the east and west office lofts and created an even higher degree of comfort."
As efficient as the building is, the team missed an opportunity to save even more energy when they decided that plug loads and the facility's data center were mostly outside their scope. "We've worked with our IT department to improve the efficiency of our standard equipment, and integrate software to shut down the PCs whenever they aren't in use, but the conservative nature of IT philosophy has made for slow progress," reports Akerstream. As a result, these "unregulated loads" account for half of the building's overall energy use.