In the process of researching an article about a Sydney, Nova Scotia-based company called Advanced Glazings, I learned about the design and construction of the Port Hawkesbury Civic Centre and hockey arena in the small Cape Breton town. In addition to using Advanced Glazing’s insulating glaze to allow natural sunlight inside the hockey rink — a North American first, I believe — the architect in charge of building the complex also got creative with geoexchange (low-temperature geothermal or heat-pump) technology.
Roughly 75,000 linear feet of geothermal loop were laid six feet below the ground and served as the core of the geoexchange system. But on top of this, architect Bob Ojolick and Winnipeg-based heat-pump specialist Ice Kube Systems decided to take advantage of waste heat resulting from the rink’s ice-making process.
You know all that steam that you usually see coming out the back of hockey rinks? That’s the byproduct heat from the refrigeration system used to make arena ice and keep it cool. Instead of letting all that steam just go into the air — which most arena’s sadly do — the Port Hawkesbury team built a system that would recover the heat.
What do they do with it? Well, the bleachers and floors in the arena, as well as some sidewalks outside of the arena, are lined with a loop system that carries food-grade ethanol. The ethanol carries the captured waste heat through the arena, providing enough radiant heating to keep the entire complex comfortable.
“It’s so successful that in the middle of February last year they had enough waste heat to send outside and melt the snow on the sidewalks,” Ojolick told me in an interview.
He figures the cost of putting in the system added a few per cent to the overall price tag of the complex, with an estimated payback of 10 years on that premium taking into account the savings of not having an energy-intensive boiler at the back of the building. No natural gas, oil or electricity is required for heating. The radiant heating, and even hot water for the showers and sinks, is all provided through the heat-pump system.
It’s an amazing case study that shows how much communities can do by thinking outside the box. It also demonstrates that even with a tight budget, those willing to pay a little more on the front end will see substantial gains over time and have the environmental bragging rights that go with it.
By the way, my feature on Advanced Glazings will appear next Monday. It’s another interesting example of how new technologies — in this case high-tech glaze for windows — are making it easier for architects to design green, sustainable buildings. I’ll post the story here when it’s out.