National Institute of Standards and Technology: Central Steam and Chilled Water Plant with 3500 Ton Chiller Expansion

From automated teller machines and atomic clocks to mammograms and semiconductors, innumerable products and services rely in some way on technology, measurement, and standards provided by the National Institute of Standards and Technology.  Founded in 1901, NIST is a non-regulatory federal agency within the U.S. Department of Commerce. NIST’s mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.  The NIST Laboratories, conduct research that advances the nation’s technology infrastructure and is needed by U.S. industry to continually improve products and services

This project called for an expansion of the existing chiller building to house a new 3500 ton chiller, heat exchanger, and pumps as well as a new electrical distribution building and a new field-built fiberglass cooling tower to support the significant increases in the size and scope of the Gaithersburg Campus. This facility not only supports climate and comfort control for the offices, but supports a significant heat load generated by the computers and equipment utilized by the scientists in the many advanced materials and process laboratories. The project was also designed to take advantage of free-cooling and variable speed pumping to improve the energy efficiency of the utility plant.

The project required adding the building addition and the new chiller to the existing building without any interruption to the functions of the operating plant. Precautions were taken for debris and dust control as well as for user protection and continual access. The primary delivery point for the existing plant was in the west wall of the building where the new addition was constructed and it was kept available to the plant throughout the construction process. As part of the procurement, the roof on the existing chiller building was refurbished. The new cooling tower was located remote from the building which required underground insulated hydronic piping to be installed along the existing cooling towers to the new tower. The new tower basin and weir were constructed of concrete below grade and required significant excavation and shoring for its installation.

Three new 13kv electrical feeders were brought to the site to a new remote electrical support building. At this building the voltage was reduced at 3 outdoor oil-filled transformers to supply power to the pumps, fans and chiller motors. Extensive coordination was required to tie these new feeds into the campus loop to assure not only minimal down-time to the electric services to critical experiments but also to protect our workers in compliance with NFPA 72E.

A new building automation and control system was also installed concurrently by NATIVE SONS under another contract and the new equipment installed under this contract was integrated into the new system without any disruption to the existing plant operations. The many pumps and fans were all powered by variable frequency drives which were seamlessly added to the controls of the existing plant.  While there were numerous tie-ins to existing services and piping, the operating plant did not lose any capacity during these required interfaces.