AECOM provided mechanical, electrical, fire protection and plumbing and geotechnical engineering for the project as part of a team of consultants that worked in close collaboration along with the client. This fused approach from the early stages of the project resulted in its innovative features and systems.

The key design challenge for AECOM's engineers was how the building could automatically adapt to a continuously changing climate with a temperature swing of more than 100 degrees Fahrenheit. Winnipeg is the coldest city in the world that has a population of more than 500,000. While the temperature stays below zero almost half of the year, it climbs in the summer to an average in the nineties, presenting dramatic needs for both heating and cooling in an efficient manner.

Relying on passive heating strategies even in the depths of winter, the building is drastically more energy-efficient without compromising comfort. The features that make this possible include a double façade on the east and west faces that creates a three-foot buffer between the interior and the frigid outdoor temperatures. Manually operated interior windows work in conjunction with automated exterior windows and shades so that solar heat is trapped within.

Three six-story atria on the building's south side are the building's lungs, completely refreshing the indoor air through a displacement ventilation system. Geothermal heat pumps draw warmth from beneath the ground and circulate it through radiant slabs embedded in the concrete ceilings.

During the summer months, all of these systems reconfigure to provide passive cooling. An internal shade is drawn inside of the façade. Water walls in the south atrium, heated during the winter to provide humidification, are chilled during the summer to cool and dehumidify the air. The double façade serves to reject solar heat gains by sealing the interior wall behind the blinds and opening the outer wall to let heat be purged.

A solar chimney at the building's north axis allows warm air gathered from each floor to vacate the building, aiding the natural chimney effect with a black body mass suspended in the chimney and exposed to solar radiation.

The building is highly intelligent, using a computer-based building management system (BMS) to synchronize its many and complex systems such as the HVAC, blinds, lighting, security and exterior windows. While the building is oriented so that 80 percent of indoor spaces receive daylight, lights suspended from the exposed concrete ceilings reflect off the ceiling to blend the artificial with the natural light seamlessly.

T5 high-output fixtures have motion sensors to conserve energy and respond to occupants automatically. The lights can also be controlled by individual occupants for maximum utility. LED (light-emitting diode) sources have been used throughout the building for increased energy efficiency.

When outdoor conditions are pleasant, the building functions nearly as a natural environment. Both walls of the façade are opened to let the outside air in; the ventilation systems are turned off; and the solar chimney vents warm air. In this way, energy is not wasted in the times when climatic conditions do not require a mechanized response. "As perhaps the most dynamic building in North America, Manitoba Hydro was designed not only to offer its occupants a comfortable, healthy workplace, but to push the envelope of building engineering and instill pride in its users and community," said AECOM Vice President John Munroe. "The building achieved energy savings over 60 percent, fulfilling the mission of its occupant, who promotes renewable energy and energy efficiency."

Jake Herson