Leading-edge environmental and sustainability technologies are the focal point of Toronto’s Evergreen Brick Works.
By Jay Egg, Egg Geothermal
Don Valley Brick Works is a century-old site that provided bricks for Toronto and the surrounding area into the late 1980s. By then, the quarry had become exhausted and it was no longer profitable to make bricks. The site also had become surrounded by Toronto and its suburbs.
Listen to a conversation between Jay Egg and Commercial Architecture Editorial Director Gary Parr.
Several attempts were made to use the property, which was burdened with a “damaged ecosystem, crumbling buildings, and contaminated soil.” The resurrection started in 2002 when part of the property was used to launch a native-plant nursery to provide youth employment and skills development. A subsequent series of ideas, events, and financial-support successes resulted in establishment of the site as Evergreen Brick Works. The facilities and programs represent Canada’s first large-scale community environmental center, providing a “dynamic venue for exploring ideas and leading-edge green technologies, and a vibrant public space where visitors can engage in a broad suite of hands-on environmental programming.”
The Evergreen program has benefitted from Ontario’s Climate Change Action Plan, a five-year effort to fight climate change, reduce greenhouse-gas (GHG) pollution, and transition to a low-carbon economy. The program is administered and funded by GreenON, Toronto (greenon.ca), and is designed to help implement technologies that will reduce GHG emissions, including geothermal systems that use ground-source heat pumps.
One of the features of the Evergreen Brick Works kiln-building renovation is a closed-loop geothermal system installed by GeoSource Energy, Brant, Ontario (geosourceenergy.com). The GeoSource system plays a major role in making Evergreen Brick Works a test site for new and more-sustainable design and construction practices, aimed at making it one of Canada’s only carbon-neutral sites.
It’s important to understand the differences between net-zero and carbon-neutral facilities. Net-zero projects create or produce as much energy as they use, but the net-zero approach does not take into account the resulting carbon emissions from combustion heating with fossil fuels. This is the root of the challenge faced by our planet. The whole world could be operationally net zero, but GHG emissions would skyrocket, further accelerating global warming.
The answer is to follow the lead of projects that have chosen a carbon-neutral path, such as the Evergreen Brick Works. To be carbon neutral, i.e., have net-zero emissions (NZE), on-site fossil-fuel combustion must be eliminated. Everything on site must be powered with electricity, and/or use renewable-energy technologies. The province of Ontario has recognized this and their Climate Change Action Plan provides education and endorsement for heat pumps, specifically geothermal heat pumps (GHPs).
Heating without combustion can require research into different combinations of renewable energy (RE), and Evergreen Brick Works personnel did their homework. The team has been working together for quite some time to ensure that the 53,000-sq.-ft. historic kiln building, which is surrounded by a window wall, could be preserved, all the while making certain they could cool and heat without combustion and the resultant carbon emissions.
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Geothermal and insulation
Two big concerns with the geothermal system were the limited space available to drill boreholes, and having to work with a building that could not be insulated enough to effectively hold heat because one of the restrictions is to preserve the look, inside and out. This resulted in the need to use borehole thermal energy storage (BTES). The site uses 260 solar-thermal panels to collect and pump heat into the 40 boreholes, each 605-ft. deep. Panel heat not needed for the boreholes is used elsewhere at the Brick Works site.
The floor of the kiln building was one place insulation could be provided without violating preservation regulations. The facility had to be elevated above the 5-year/2-year floodplain, a difficult task to do while maintaining the facility’s historic integrity. According to Drew Adams, project architect with LGA Architectural Partners, Toronto (lga-ap.com), even with the floor raised and insulated, flooding will occur from time to time, so care was taken to ensure all equipment was inside, elevated, and protected. Since geothermal systems need no outside condensers, they simply made certain that the GHPs were installed inside and above the main flood plain.
Raising the floor included installing a Cupolex in-floor system, manufactured by Pontarolo Engineering Inc., Vaughan, Ontario (cupolex.ca), to provide insulation for the radiant in-floor heating and cooling, create a void space below the surface, reduce the amount of needed virgin granular, and provide an internal drainage system for flood and ground water.
In the cross-section above, it’s clear that the Cupolex technology saves a lot of concrete, provides an insulation barrier, and is quite strong. The concrete includes a certain amount of recycled aggregates and, together with Crete Dufferin Foamcrete provided by CRH Canada Group Inc., Concord, Ontario (crhcanada.com), the floor system attained an R-5 value. The third layer of the surface includes radiant piping, installed before pouring the final layer. This important feature provides heating and cooling to occupants, depending on seasonal needs.
Andrew Bowerbank is the global director of Sustainable Building Services at EllisDon Corp., Mississauga, Ontario (ellisdon.com), construction partner for the Evergreen project. The Kiln Building Redevelopment project is part of EllisDon’s Carbon Impact Initiative, and is one of the first projects to strive for a carbon-neutral target.
According to Bowerbank, EllisDon has a cradle-to-grave level of involvement in their projects. Their approach to carbon neutrality includes four main tiers:
• pilot projects, such as Evergreen Brick Works
• accurate accounting for GHG emissions
• vetting of new technologies
• calculation methodology for return on investment.
The Evergreen Brickworks project has become a real-time learning laboratory for each of these four tiers. Bowerbank said that, as a result of their Evergreen work, they have developed a landmark tool for accurate accounting of GHG emissions, one they hope will become the standard for buildings everywhere. Click here to learn about the tool.
An educational future
The building is a living laboratory, and as such, the local masonry union, Ontario Masonry Training Centre (OMTC), obtained a grant to practice some stabilization techniques to some of the masonry infrastructure. The adaptive-reuse facility is filled with modern technology including solar-thermal, geothermal-exchange, and pumping systems.
The project was first established in 2007, opened in 2010, and has been a constant focus of funding and construction since then. The kiln building was partially re-opened to the public in the spring of 2018, while construction of the classrooms and galleries continued. Completion and official opening is scheduled for spring 2019. Perhaps one of the most visible projects in Toronto for green infrastructure, the Evergreen Brick Works facility is a test platform for EllisDon, Evergreen, and many others as they perfect green construction and management and reduce GHG emissions.
Jay Egg is a geothermal consultant, writer, and owner of EggGeothermal, Kissimmee, FL (egggeo.com). He has co-authored two textbooks on geothermal HVAC systems published by McGraw-Hill Professional and can be reached at firstname.lastname@example.org.
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