UPDATE: CO2 solution cools 3 ice rinks & heats 2 pools, a library and a gym

By Alexandra Maratou, Feb 26, 2014, 09:46 2 minute reading

R744.com visited the Dollars-des-Ormeaux ice rink complex in Montreal, Canada, where the old R22 system has been replaced with a new CO2 refrigeration solution by Carnot Refrigeration. Not only does the system allow for the three ice rinks in the complex to be perfectly iced, it also provides heat for the two adjacent pools, a library and a gym. Preliminary results show energy consumption savings of 38% for the ice rinks alone. UPDATE: In February

In operation all year round, the energy consumption of the Dollars-des-Ormeaux sports facility complex totaling 164,311 ft2 (15,265 m2) of surface totaled up to 14,000,000 kWh/year in the past. To reduce the energy consumption, the old HCFC22 refrigeration system that catered to the cooling needs of the three ice rinks of 17,000 ft2 each (1,580 m2) was replaced with a new CO2 refrigeration solution designed and produced by Carnot Refrigeration.

Project wins Energia Award

Organised for the 24th consecutive year, the Energia Award of the Quebec Association of Energy Efficiency (AQME) recognised excellence in energy efficiency in 13 different categories in February 2014. Carnot’s project at the Dollars-des-Ormeaux sports facility won this prestigious award in the ‘Existing building – institutional sector’ category.

Compact CO2 system required no major change in the mechanical room

The system’s compactness combined with the simplicity of Carnot’s factory-manufactured CO2 transcritical solution did not require any major change in the mechanical room and allowed for the reuse of existing pumps and piping for the brine/glycol closed loop.

The main components of the CO2 system include:

  Quantity Capacity (kW)
Compressors 18 724
Brine Pumps 3 11.25
Heating Pump 1 3.75
Heat exchanger 4 274
Heat recovery 8 880
Gas cooler 2 1160
Refrigerant CO2 5,456 lb (about 2,474 kg)  

Preliminary results show 38% of energy savings for cooling

Just two months after the installation of the CO2 refrigeration system, the total energy consumption of the arena decreased from 48,000 kWh/day to 29,500 kWh/day, which equals up to 38% of energy savings. This does not include the additional energy savings on the heating bill thanks to heat reclaim.

According to preliminary estimates after 1 year of operation, the energy consumption is reduced by 33.4% (4,700,000 kWh), while the heating expenses have declined by 81% compared to the previous system.

Some of the secondary impacts of the CO2 transcritical system include:
  • 60% less space needed for refrigeration equipment
  • 10% reduction in maintenance costs compared to a conventional system
  • No cooling water tower is required

Heat recovery technology provides better system optimisation and additional energy savings

The heat not used by the desuperheater at the cooling stage, where the pressure is lowered to increase system efficiency, is sent to the arena’s heat recovery units.

The heat recovery technology not only provides better optimisation of the refrigeration system but also caters to part of the heating needs of the two adjacent pools, and a library, two big rooms and a gym.

When the heat recovery is not needed, the refrigerant is sent to the gas cooler (condenser).

About Carnot Refrigeration

Established in 2008 with the goal of addressing the industry’s need to provide industrial and commercial clients with a thermodynamic option that would diminish environmental impact, Carnot Refrigeration makes a conscious effort to design refrigeration systems and heat pumps that use environmentally friendly natural refrigerants such as CO2. The company is experienced in meeting the needs of sports facilities (arenas), large and small supermarkets, distribution centres and the agri-food industry.


By Alexandra Maratou

Feb 26, 2014, 09:46

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