Deep Lake Water Cooling in Toronto
The Munich Re Centre in Toronto has long played a part in combating climate change. Projects initiated include updating the lighting system and retrofitting the building with more energy-efficient electric motors. When the air conditioning recently reached the end of the road after nearly 35 years’ service, it was decided to connect the building to the Enwave utility company’s innovative Deep Lake Water Cooling (DLWC) system. This has now replaced the three chillers and two cooling towers of the previous system.
The DLWC concept is as simple as it is fascinating: Toronto lies on the shores of Lake Ontario. As with any large body of water, the temperature at the bottom of the Lake is at a constant 4°C. DLWC technology takes advantage of this by drawing water from a depth of 83 metres and using heat exchangers to transfer energy between the lake water and a closed, chilled-water supply loop. The system is already used to cool a large number of buildings in downtown Toronto. It has sufficient capacity to chill about 300,000 m2 of office space.
The benefits are obvious: the system uses about 90% less energy and thermal discharge into Lake Ontario is much less than from conventional power plants, annual CO2 emissions having fallen by 1,180 tons. However, the advantages are not just environmental but also economic. Both over the 10-year and 20-year horizons, the rates Enwave charges for delivering cold from the deep are more than offset by savings in investment and maintenance. There were no doubts about DLWC’s reliability since Enwave has supplied the Munich Re Centre with district heating ever since the building’s inauguration in 1972. The Munich Re Centre can look forward to summer, secure in the knowledge that the Deep Lake Water Cooling system will make a positive difference in the fight against climate change.