GCHP system helps polar bears keep their cool

The Assiniboine Park Zoo in Winnipeg, MB is building an International Polar Bear Conservation Centre and the Journey to Churchill Polar Bear exhibit that will be opened to the public in 2014. The four buildings under construction for the exhibit (the Conservation Centre, Tundra Cafe, the Gateway to the Arctic Exhibit Building, and Aurora Borealis Theatre) are connected to a common GHX. The GHX design is unique in that it...

is actually comprised of two different GHX modules. To create the outdoor exhibit space for the bear enclosure a mound of earth up to 12' (4 m) in height was built. High density polyethylene (HDPE) pipe was laid in a 3' (1 m) excavation prior to building the earth mound to take advantage of the cover. This provided approximately 20% of the capacity of the GCHP system at very low cost to take advantage of the earth work. To provide the remainder of the heating and cooling capacity for the buildings, a horizontal directionally drilled GHX was built under the existing parking lot adjacent to the zoo.

Other unique features of the GCHP system for this project include:

• The connection of 4 separate buildings to a common GHX to create a district geothermal system. This takes advantage of the diversity of buildings and provides more opportunities to transfer energy directly from one building to another.
• Conditioning of two pools for polar bears and seals. In winter, the pools are heated enough to maintain some open water in the pools, and chilled in summer to provide a cool respite for the northern animals.

Designing a GHX around proposed earth work can significantly reduce the cost of building a GHX for a project. This can eliminate a significant portion of the cost of building a GHX since the earth will be moved regardless. Modeling and planning the logistics of placing the pipe must be well coordinated with the entire design and construction team to facilitate the placement of the pipe without disrupting other work.