How our experts helped the city of Varennes, Quebec, overcome the challenges of building Canada’s first Net Zero institutional building.
Eyes on the screen
Visitors entering the award-winning public library in Varennes, Quebec are immediately drawn to a computer screen in the lobby. The screen displays a bar graph of the building’s real-time energy consumption and production. People are fascinated by this energy scale; they want to know how the building works. The head librarian has given so many tours that she’s become somewhat of a building expert herself.
The passion for learning that library guests exhibit is not surprising to those familiar with Varennes. This Montreal suburb is home to top-notch technical research centers: Institut de recherche d’Hydro-Québec (IREQ), Institut national de la recherche scientifique (INRS), and CanmetENERGY, Canada’s clean energy research and technology organization. So when the city decided to expand its municipal library, it also opted to showcase its community’s technological knowledge. How? By building Canada’s first institutional Net Zero building.
The challenges were many. Quebec’s northern climate was one. With record highs of up to 38 degrees Celsius (100 degrees Fahrenheit) in the summer and record lows of minus 42 Celsius (minus 44 Fahrenheit) in the winter, temperatures fluctuate greatly. Our team had to ensure that the building would provide comfort and dependability—affordably—no matter the weather. So how did they do it?
Every watt counts
The team began by setting the energy consumption bar low. Because for Net Zero, the fewer watts of energy you consume, the fewer you must produce—which keeps costs down. Before the building was designed, we simulated the energy usage of every piece of equipment. We looked for low-energy appliances, like LED lighting. And we sought other solutions, like natural daylight. The building, which opened in December 2014, consumes nine times less energy on average than similar buildings across the country. This was achieved in part by:
Installing 425 solar photovoltaic panels on the southern side of the roof pitched at 37°. With these, 35% of the sun’s energy is transformed into thermal energy, which is recovered by the ventilation air.
Installing heat pumps, geothermal wells, and strategically placed radiant floors. These systems use the sun’s heat and stable ground temperatures to regulate heating and cooling—using merely one quarter the energy of traditional baseboard heating.
Designing a less energy-intensive—and quieter—alternative to standard ducting. Displacement ventilation and electrically controlled motors diffuse fresh, cool air into the room at floor level and vent warmer air from the ceiling.
Having windows open and close automatically. Letting in fresh, cool air as needed further reduces the building’s need for air conditioning.
Placing CO2 sensors throughout the building. These sensors continuously measure occupancy so building systems can fine-tune their energy requirements as needed.
One of the team’s most creative solutions was making use of the ventilated space between the rooftop solar panels and the roof itself. In winter, air passing through this space is preheated by the panels before it reaches the fresh-air intake—a huge energy saver in cold climates. This space also vents excess heat from the glinting panels in the summer, stopping them from overheating and losing efficiency.
The building’s impressive Net Zero energy performance garnered the project a Canadian Consulting Engineering Award. The Varennes public library is proof that net-zero is possible, regardless of climate. Meanwhile, building owners should prepare for this eventuality by designing “Net Zero-ready” buildings now. This way, when the technology becomes more mature and affordable, they can easily adopt the technology.
About the AuthorMore Content by Laurier Nichols