Buildings in Chicago need air conditioning – sometimes even year-round. For decades, most buildings used on-site chillers to condition their space. But faced with a phaseout of chlorofluorocarbons (CFCs) in the early 1990s, many buildings began to look to alternatives such as district cooling then newly offered by Commonwealth Edison.

ComEd set up its district cooling company in 1993 and started constructing an ice-storage thermal energy plant at State and Adams. It began pumping chilled water to an initial dozen customers in 1995. Under ComEd and subsequent owners Unicom, Exelon, Macquarie Infrastructure Co. and now Brookfield Infrastructure Partners, the chilled-water system has expanded to meet the cooling needs of downtown buildings.

Plant P-1, State and Adams
Startup: May 1995
Current capacity: 20,000 tons, plus 66,000 ton-hr ice tank

Plant P-2, Franklin and Van Buren
Startup: July 1996
Current capacity: 23,000 tons, plus 125,000 ton-hr ice tank

Plant P-3, 300 E. Randolph
Startup: May 1997
Current capacity: 23,000 tons, plus 100,000 ton-hr ice tank

Plant P-4, Merchandise Mart
Purchased: June 1997
Current capacity: 20,000 tons, plus 24,000 ton-hr ice tank

Plant P-5, 300 N. Wabash Building
Startup: June 2002
Current capacity startup and expansion: 15,000 tons

Brookfield acquired Thermal Chicago from Macquarie Infrastructure Company in August 2014, renaming Thermal Chicago as Enwave Chicago. Brookfield also owns and operates similar district energy systems in Toronto, Houston, New Orleans, Seattle, Las Vegas and Windsor, Ont., Canada.


Quiz Yourself

How many gallons of fresh water can a 100,000-sq-ft building save annually by using district cooling instead of chillers?