PISCATAWAY, N.J. - Tanglewood Mall in Roanoke, Va., needed a major renovation to keep current tenants and their customers comfortable while luring new tenants to fill the available spaces. Not satisfied with a cosmetic facelift, mall manager Urban Properties tapped Trane to coordinate a $1.8 million turnkey project to replace the building's 33-year-old chilled-water plant.

Many components of the existing chilled water plant, which was built in 1973, had failed, making it unreliable and costly to maintain. The mall was especially interested in cutting energy costs, since it acted as a utility, invoicing tenants for electricity and chilled water use.

Replacing the old chilled-water system would maintain a comfortable environment for current tenants, provide the extra capacity required for new tenants, and cut energy costs. In fact, the old cooling towers leaked so much water, replacements are anticipated to save $5,000 in domestic water usage annually, plus the cost of the lost water-treatment chemicals.

Work on the 1,800-ton chilled water plant began in May 2006; the changeout is occurring during the hottest summer months. Upon its anticipated completion in September, the mall will have:

  • Two CVHF 910 high-efficiency centrifugal chillers.

  • Marley cooling towers.

  • ABB variable-frequency drives.

  • Bell and Gossett pumps.

    The entire plant will be controlled by Tracer Summitâ„¢, employing chiller plant manager software to optimize both the chiller itself and the condenser side of the system by orchestrating proper use of the variable-flow condenser pumps and variable-flow condenser fans.


    "The existing mall has no air-side economizers, making this a candidate for chiller-free cooling," says Bill Upthegrove, manager of high performance buildings for Trane.

    "During times of reduced wet bulb temperatures, cold water from the cooling tower will allow the chiller to produce cold water for the mall without operating the compressor," he said. "This has the potential for large utility savings during the holiday shopping season."

    Supply-side pumping horsepower should be reduced by converting the plant to a variable-flow primary pumping system, he said. Mall technicians will be able to access some plant controls from home with their laptop service computers.

    "The coordination of the project has gone very smoothly," said Tanglewood Mall Manager Jake Repass, Urban Retail Properties. Trane has been serving the Tanglewood Mall for 33 years.

    To see how the Trane Tracer Summitâ„¢ building automation system controls climate, lighting, energy consumption, scheduling, and other building features, visit www.traceres.trane.com/demo/retail/index.htm.

    Publication date: 08/28/2006