USPS Cardiss Collins (Chicago) P&DC HVAC System Modifications

The chillers, chilled water pumps, and condensing water pumps at USPS Cardiss Collins, Chicago, were in a state of disrepair. They needed immediate replacement. The USPS was spending significantly on annual repairs to maintain the chillers and pumps, which was no longer a cost-effective solution. DLZ recommended replacing the chillers and pumps with new equipment that was far more energy-efficient and significantly reduced both energy costs and maintenance costs.

The project includes the complete replacement of the existing chiller plant that serves the +/-1,000,000 square foot Processing and Distribution USPS Cardiss Collins Center at the Harrison Street facility in Chicago, Illinois.

DLZ replaced four existing 650-ton water-cooled chillers, with four 600-ton chillers, including the associated primary chilled and condensing water pumps.  The chillers connected to the existing pipe distribution system.  DLZ provided New Direct Digital Controls (DDC) for the chilled water plant and interfaced with the existing Building Management System.

The project included performing a load calculation of the existing facility to determine if the chilled water plant had a proper size.  The calculations determined the total chilled water plan size could be reduced, resulting in lower construction costs to the USPS due to the reduced size of the chillers. The pump sizes were also revised based on the reduced flow demand with the smaller chillers.

Through close coordination, our team completed the project on time and under budget.

DLZ performed the following services:

  • Investigative Study
  • Design Services
  • Energy modeling
  • Energy compliance certification

Cost estimating Construction Administration




Federal Government


Chicago, Illinois