Client:   Dun & Bradstreet,   Berkeley Heights, NJ

Contact:    Mr. Fred Tabertshofer

Project:     Replace Existing Chillers

Background – Dun & Bradstreet maintains a major data processing center in Berkeley Heights, NJ.  The chilled water plant, which is vital for the mainframe computers as well as providing environmental control for historical data storage, consisted of two, 30-year old water cooled chillers, and two 15-year old air cooled chillers.  Interruption of the chilled water system results in a cost to production of $50,000 per hour, and can cause unpredictable data errors and associated start-up problems. 

 Intent – The client wanted to replace the chillers to provide a reliable chilled water plant with redundancy.  Elimination of the chloro-fluorocarbon refrigerants, which are known to damage the ozone layer, operational energy savings and the ability to take advantage of available energy rebates were also objectives.

 Conceptual Challenges – 1) To site and install the new equipment while the existing remained in operation.  2) To complete the installation within a limited timeframe to take advantage of rebates before they were phased out.  3) To modify the existing underground   chilled    water   storage   tank piping with minimum interruption to redundancy, and no interruption of the chilled water system’s end use.  4) To replace the complicated, installed piping system with a simple, redundant system. 5) To accomplish the piping changeover to the new system with no interruption of the chilled water system.  6) To keep the cooling tower in service during construction.

  

 Details – 1) Space for the new chillers was created by constructing a building addition.  2) A new cooling tower was installed and temporarily piped to allow demolition of the old tower.  3) The chilled water system was changed to a de-coupled primary/ secondary variable frequency drive system to reduce system pressure, increase energy efficiency and increase redundancy.  4) Chilled water piping to the critical area was installed with welded joints, while grooved joint piping was eliminated for increased reliability.  5) The connection to the new chilled water system was accomplished by providing hot taps downstream of the tie-in points with temporary piping to those points from the new system.  The piping in between the hot taps and the tie-in points was then frozen, so the permanent connections could be made.  6) The project cost was approximately $2.6 million for which BUIST was responsible for half.

 Results – 1) The project was completed on time and within budget.  2) There was no interruption of services.  The reliability of the chilled water system was greatly increased by the design changes implemented.  3) The energy rebate was secured because the project was completed on time.  4) The client’s Project Engineer was pleased with the system pressure reduction and the redundancy afforded by the primary/secondary pump system.  5) Permission to speak with the client may be arranged upon request.