sSOW York Chiller replacement.docx

SOW Replacement of 1302 York Chiller

The Foreign Disease-Weed Science Research Unit (FDWSRU) conducts research on emerging plant pathogens in Biosafety Level (BSL)-3 and BSL-2 laboratories and requires a functioning dual chiller system that meets specific requirements to service multiple water-cooled plant growth chambers to support research needs. Bldg 1302 contains 3 walk-in and 8 reach-in fluid-cooled controlled environment plant growth chambers that house research projects critical to the mission. Fluid-cooled heat exchange on the units ensures that excessive heat from chamber operations does not build up inside bldg. 1302. These plant growth chambers are serviced by two existing 56-ton York chiller units external to the building, one of which has met its end of service date and is no longer functioning.

We require the replacement of the non-functioning chiller with a York chiller of sufficient capacity to pair with the existing 56-ton York model to provide redundancy in delivery of chilled fluid and maintain critical research being conducted in the plant growth chambers without interruptions caused by individual chiller failure, which is currently happening with problematic frequency, causing loss of research materials. In addition, two chiller pumps that deliver chilled fluid from the chiller units to the growth chambers have met the end of their service dates and must be replaced to ensure continuing functionality of the system. Deteriorated insulation, piping and valves must also be replaced to prevent fluid leakage and ensure energy conservation as chilled fluid is moved from outside the building through the chambers and returns to the chillers.

We require removal of the one old York chiller that has met its end of service date, and installation of a new York chiller unit on the existing concrete pad. The contractor shall tie in the new chiller with the existing operational York chiller and install a York chiller-compatible Johnson Controls Inc. control system to provide redundancy of chiller operation, automatic restart of each chiller in the event of power surge or failure, and automatic switchover between the two chillers with periodic recurring exercising of each chiller. The control system shall have set points for supply and return temperature and integrate the new pumps with both chillers. An alarm light shall be installed in the 1302 hallway to function in alerting staff of chiller malfunction. We require removal of two old chiller pumps and replacement with two new 7.5 horsepower pumps, providing at least, with fluid delivery of at least 130 gallons of chilled fluid per minute. In order to provide redundancy of operation, we require installation of new valves and piping, and insulate and repair damaged piping to connect the new chiller. The contractor shall test the system upon installation of all components to ensure that the controls and settings provide the proper supply and return temperature and redundancy of operation. Testing shall include automatic restart and alarm upon chiller failure.