A Solution For The Future
February 1, 2013 | By Luc Boily
Marcel-Dutil Arena in Quebec is the first rink in the world that uses 100 per cent carbon dioxide in its cooling system.
Marcel-Dutil Arena in Quebec is a leading edge refrigerant application, which was made possible through the development of new compressors and new control valves. Let’s remind ourselves that the cooling system of traditional rinks contains ammonia or freon as primary refrigerant, and water/glycol, brine or methanol as secondary refrigerant. The rink at Marcel-Dutil Arena uses R-744 (CO2), a natural, non-toxic, non-corrosive and high efficiency refrigerant in both its primary and secondary systems.
Innovation
In partnership with the distributor Inno-Glace and others, Groupe-conseil Roche Ltée developed an innovative solution which earned the firm a Visionary award in the mechanical electrical building category, from the Association des ingénieurs conseils du Québec (AICQ). Roche was involved in the CO2 system adaptation, the main pipes running from the mechanical room to the rink, and the layout of some 16 500 m of copper pipes in the concrete slab of the rink. The capability of the system, which includes seven 20 HP compressors, is up to 70 tons. A three HP variable speed pump allows the CO2 to flow freely in the entire piping system.
Bernard Landry, executive engineer at Roche, explains that as there is no phase change inside the pipe network under the rink, the CO2 temperature remains the same from input to output. Thus, ice can be maintained at a steady temperature, which cannot be done with a traditional system.
“With this new technology, a liquid state CO2 is pumped from a low pressure tank directly to a pipe network into the concrete slab. Since there is no secondary refrigerant, we can adjust the evaporation temperature at -7C, while maintaining the ice temperature at -5C,” said Landry.
Luc Simard, engineer at CSC Group Inc., the cooling specialist firm that has developed the equipment used at the Marcel-Dutil Arena, sees a brilliant and exponential future for CO2 systems. “Several projects using carbon dioxide are currently on the table, and many municipalities have sent a request to the Quebec’s ministère de l’Éducation, du Loisir et du Sport (MELS) to get a grant to convert their old R-22 system by a new green CO2 system,” reported Simard.
Other benefits
The cooling system is not the only innovation involved. A heat recovery system, as the temperature of the water is about 71C (160F) instead of the 32C (90F) seen with traditional ammonia systems, takes care of 80 per cent of the heat demanded by the building, and 100 per cent of the heat demanded by domestic hot water, mainly for showers and ice resurfacing.
For the municipal government, the choice of this technology has not only allowed the arena to be more energy efficient – saving about 30 per cent on utility bills – but also to meet the requirements of the Montreal Protocol, which phases out ozone depleting substances, including refrigerants such as freon, by 2020.
The mayor of Saint-Gédéon-de-Beauce, Eric Lachance, is proud to have dared to make the change. “I’ve already made a place near my wood stove for a Phénix and an Énergia award,” he said with a smile. <>
Luc Boily is the editor of Plomberie, Chauffage & Climatisation, HPAC’s French language sister publication. www.hpacmag.com
