Chicago's underground chilled water distribution system serves over 100 buildings within the city through 15 miles of underground piping. It is one of the most advanced, reliable, and efficient cooling systems in the world. ESD provided engineering design services for two of the systems's five chilled water generation plants throughout the city, as well as technology consulting services and distribution system master planning services.
Plant #1 is located in Chicago's Central Loop and is a 25,000-ton chilled water generation plant with three 5,000-ton electric, motor-driven centrifugal chillers and 66,000 ton-hours of ice storage. Plant #2, at the edge of the Central Loop, hosts the largest ice tank of its kind. The tank is 40 feet deep, holds 2,000,000 gallons of chilled water, and can deliver 125,000 ton-hours of cooling to the system.
The system works by producing ice during off-peak hours when electricity costs are at their lowest. For the electric utility, off-peak cooling production reduces their need for infrastructure or energy production capacity. For new buildings, this allows for upfront cost and space savings, while existing buildings have been able to phase out their aging chiller plants and reduce their mechanical footprints.