The decision to use radiant capillary mat heating technology introduced a twist into Olympic Village construction – an installation learning curve for everyone involved.
“Because we used new products the construction trade isn’t used to, there were no established ground rules or traditions on who handles what.”
Mike Mahannah, Olympic International
“This system is integral to the drywall ceiling,” says Peter MacLellan of Olympic International. “So the mechanical contractor had to work very closely with the guys doing drywall – not something that usually happens. And the capillary mat installers had to work with the folks doing the lighting – all the trades really had to work together.” Installation companies found it challenging to provide cost estimates for technology they didn’t know, says Mike Mahannah, President of Olympic International. “Initially there was some resistance. We had a lot of upfront meetings where we showed them the tools, showed them it’s not that complicated. Then the guys on site really got into the rhythm of it.
“Since it was such a big job, we now have five different mechanical contractors who are really comfortable with the process. That capacity will assist these systems to be much more easily adopted in future.”
The capillary mat system offers an economic advantage not permitted by traditional forced-air systems: recapturing vertical space on each building storey. Air ducts for forced air heat typically require 15 inches of space inside the ceiling. By contrast, the capillary mats require less than an inch. This means the developer can choose from several options: offering suites with attractively high ceilings; fitting more storeys (more marketable floor space) into a given height restriction; or reducing the overall height – and materials cost – of the building. In any case, there’s a market advantage that makes the radiant heating system economically attractive.
Throughout the Olympic Village, hydronic (pumped water) radiant energy systems are used for cooling as well as heating. At the Community Centre there’s an added feature: the building is cooled using the sun.
“We’re using solar hot water thermal collectors to generate cooling through an absorption chiller,” says Vlad Mikler of Cobalt Engineering. “It requires very little electricity, only enough for a small circulating pump, so it uses a few orders of magnitude less electricity than conventional cooling equipment. But – it requires an input of hot water to power the cycle.”
Absorption chillers use waste heat (usually steam or hot water – in this case, heated by the sun) to generate cooling. Inside the absorption chiller, this heat is transferred to a brine solution, causing evaporation. The resulting fresh water vapour is condensed and sprayed onto pipes holding water that will circulate inside the building, cooling it. Due to a strong affinity between the condensed brine and the fresh water spray, the brine attracts and reabsorbs the spray. This creates a vacuum, lowering the boiling point – meaning that heat from the sun is adequate to continue the cycle of evaporation and cooling.
Mikler says it’s believed this is the first time a solar powered absorption chiller cooling system has been used in North America, especially at such a northern latitude. He points out that weak sunlight in the wintertime is not a problem – because that’s when cooling isn’t needed. “The demand for cooling is really proportional to the solar radiation intensity,” he says. “So it’s a perfect match.”
Buildings at the Olympic Village are estimated to be 30–70% more energy efficient than comparative buildings designed to minimum codes. This demonstrates that passive design, district energy, radiant heating and efficient appliances and fixtures can make a significant difference in energy consumption.
However, in a world facing the serious challenges of climate change, peak oil and population growth, there is still room for improvement. For this reason, Parcel 9 includes a building that demonstrates the next step: Net Zero. A Net Zero building produces as much energy as it consumes. Chapter 8 of The Challenge Series will include a special focus on the Olympic Village Net Zero building.