MEP Associates, LLC, (MEP) was engaged to perform a master plan study to determine the optimal solution for creating increased chiller plant capacity, while at the same time determining how best to interconnect multiple chiller plants. All the tasks MEP needed to perform came with the requirement to reduce energy consumption and peak demand. At the time MEP was engaged to perform the master plan, the facility utilized stand-alone water-cooled chiller plants to serve dedicated supercomputer testing bays. The test bay cooling load was at times exceeding the capacity of the associated chiller plant.
MEP analyzed how to integrate a new chiller plant to the existing two chiller plants and how this could be a phased approach to implement a solution that would provide redundancy so that any chiller plant could operate at a given time to provide the base load needed for the campus. A water-cooled economizer system was included in the new chiller plant to handle 100 percent of the cooling load. The design included a space for a 1,000 tons of future expansion.
The cooling load requirement is predominantly from the heat gain of computer equipment that is currently being tested in the adjoining labs. The facility currently needs the chilled water to be delivered at 47°F degrees. The facility made use of free cooling as much as possible. MEP designed a system that used the plate and frame heat exchangers to supply up to 100 percent free cooling, and staged the chillers to interject mechanically cooled water to maintain the 47°F degree requirement. The water from the cooling tower is cycled into a below-grade sump pit. Depending on load requirements and ambient conditions, the chilled water will all be delivered to the heat exchangers and/or be diverted allowing the 85°F degree water tower low water temperature to creep up.