The most visible part of the chilled water plants are the cooling towers. This is one of two cooling towers serving the Northwest Plant.

The most common use of chilled water is air conditioning. Building air handlers use water from the central plants to cool air and provide comfort cooling. In recent years, the plants have seen an increase in process loads. Computers and research projects all over campus use chilled water for temperature control.

The West Plant is still the largest chilled water facility on campus. At this time, all of the 19,300-tons of capacity come from centrifugal chillers powered by electrical motors. The plant is undergoing another expansion. Scheduled for completion in the summer of 2008, this project adds three 4,000-ton chillers.

A 3000-ton chiller at the West Plant. Centrifugal chillers use the mechanical refrigeration cycle to produce cold water.

The Northwest Plant houses the largest chiller in the University’s inventory. The 5000-ton unit is similar in operation to the West Plant chillers. The only difference is that a steam turbine powers this unit’s compressor.

The North Plant has a variety of chillers including two steam absorption units. Absorbers use water as a refrigerant (centrifugal units use chemical refrigerants) and rely on a chemical reaction to produce chilled water.

A 1,500-ton absorption chiller. This type of unit uses water, Lithium Bromide and steam to produce chilled water.

Underground piping connects nearly sixty buildings to the chilled water plants. Water pumped from the plants travels to the buildings through supply lines. Warm, used water flows back to the plants through return lines. The entire system is a closed loop, water continually cycles between the plants and buildings.

Chilled water distribution pump. Pumps like these supply chilled water to nearly every area of main campus.

Current chilled water construction projects include:

1. West Plant Expansion. The project adds 12,000-tons of capacity to the chilled water system. At this time, workers are in the process of finishing the new plant structure. This project should be complete in the summer of 2008.

2. Chilled Water River Crossing. This project connects the east and west campus distribution piping. This will allow chilled water to flow from any of the three plants to any building on campus.

Construction on the West Plant expansion.

For more information, contact:
Ed Stroud
Chilled Water Plants Manager
Telephone: 319-335-8625
Fax: 319-353-5538