Assignment
Real estate developer, Proment Corporation commissioned Golder with designing and optimizing the underground portion of the geoexchange system at the twin residential towers of Le Vistal in Montréal, Canada.

The geoexchange system, in addition to other aspects of Le Vistal such as its high-efficiency windows and a plumbing system that reduces water use, will help the complex attain certification to the Gold LEED® (Leadership in Energy and Environmental Design) standard.

Our Role
During the cold season, naturally-heated water from below ground is pumped to the surface, some of the heat is removed through a heat pump, and the water is returned to the depth it came from within a closed circuit. The system produces 35 percent of the building's heating and cooling load, generating annual energy savings of about C$90,000 (US$86,900) and with a payback time estimated at ten years.

However, beyond the energy and financial savings, Le Vistal's geothermal heating and cooling system will forestall the need to burn 125,000 cubic metres (4.4 million cubic feet) of natural gas and will prevent emission of over 230 tonnes (250 imperial tons) of carbon dioxide on an annual basis.

Key elements of Golder's role were:

• the planning and completion of test boreholes
• in situ thermal conductivity testing
• design and sizing of the underground heat exchanger
• preparing plans and specifications for the call for tenders
• construction site supervision