For the people: government chillers keep costs cool: federal facilities showcase our history, dispense justice, accelerate atoms, and more. While that's a broad range of activity, buildings serving those functions share one common trait: better performance through recent retrofits. Reducing costs and eliminating CFCs are just two of the benefits for these federal projects

Engineered Systems, Oct, 2003 by Joanna R. Turpin

It has been estimated that the equipment used to produce chilled water for HVAC systems in government facilities can account for up to 35% of a facility's electrical energy use. When you consider that new chillers can be 35% to 40% more efficient than existing equipment, replacing the chillers may be a good idea.

In addition, there are refrigerant issues to worry about. Older chillers using CFC refrigerants may be very expensive to recharge if a refrigerant leak occurs. And if a leak does occur, venting the CFCs to the atmosphere may damage Earth's ozone layer.

Government at various levels, from city to state to federal, are all looking to reduce costs. Replacing older equipment with new energy-efficient chillers is one of the ways facilities can reduce their utility bills and ongoing operation costs. This article will take a look at some of the chiller retrofits that have taken place recently in various government facilities.

DOE CHILLER/COGENERATION PROJECT

Smithsonian Institution facilities along the National Mall in Washington received enhanced energy services from General Service Administration's (GSA) modernization and expansion of its central heating and refrigeration plant.

The DOE Headquarters Forrestal Building in Washington began to reap the benefits of a privately financed energy efficiency project, and just in the nick of time. In June 2001, just days before the weather in Washington started to reach a smoldering heat index temperature of 100[degrees]F, the first two of eight new 2,200-ton chillers became operational. These two chillers, part of a much larger energy efficiency project, provide cooling for the Forrestal Building.

The chillers were installed in the GSA's central heating and refrigeration plant in Washington, which underwent a much-needed modernization and expansion process that had a price tag of approximately $64 million. The GSA and the Smithsonian Institution signed a Utility Energy Service Contract (UESC) earlier with their utility partner, Washington Gas, which provided the upfront capital costs of the improved heating and cooling equipment.

The new equipment included a cogeneration system as well as new chillers. Washington Gas acquired capital dollars for the project from a private-sector financial institution, GE Capital Potomac Federal. The Federal Government will repay the utility out of a portion of the energy cost savings resulting from the project.

The renovation is expected to result in lower emissions and operating expenses, but the plant's capacity to meet chilled-water needs will be greater. GSA's previous refrigeration equipment, which used ozone-depleting refrigerants, was replaced. The modernized GSA plant provides chilled water, refrigeration, and air conditioning for several federal facilities, including DOE, and eight Smithsonian Institution museums along the National Mall.

Robert Bailey, Smithsonian Institution Undersecretary for Finance and Administration, said, "This project eliminates the need for the Smithsonian to replace small, aging chiller plants in four of our museums. It also contributes to improved air quality for the region by consolidating energy output at one high-efficiency plant."

A new cogeneration system will produce electricity and steam from natural gas, allowing GSA to meet the steam requirements of more than 100 federal and local government buildings more efficiently. The system will reduce or eliminate electricity costs while generating surplus electricity for sale to the electric power distribution grid. Using cogeneration technology and natural gas will help to improve air quality in the region by reducing emissions associated with the (old system.

DUPAGE COUNTY GETS HYBRID SYSTEM

"On the hottest day of the year, we've got 1,000 tons of chiller capacity in reserve. That helps me feel secure," said Dan Baran, facilities supervisor of power plant operations at the DuPage County Governmental Complex in Wheaton, IL. Baran is referring to the recent upgrade of the driller plant and chilled water distribution system on the sprawling government campus.

The county has a municipal complex that includes 12 buildings totaling 1.5 million sq ft. These include an administration building, jail and sheriff's office, judicial office building, health department, convalescent center, juvenile detention center, and power plant building. The chillers that served the facility are located in the power plant building that dates back to 1970.

The county recently completed an upgrade of the chiller plant and chilled water distribution system. The project involved replacing three single-stage centrifugal chillers ranging in age from 18 to 30 years and totaling 3,300 tons of capacity. According to Baran, the reasons for the replacement were a desire for greater efficiency, concern about the R-11, R-12, and R-114 refrigerants used in the old machines, and increasing concern about unit reliability because of age.

The power plant building also contains three boilers that produce high temperature hot water for building healing, domestic water heating, and laundry as well as steam for humidifiers and food service. Tire boilers have a dual-fuel configuration, operable on either natural gas or fuel oil.