June 2014 saw the completion of the Demand Flow project, designed to increase the efficiency of the Meredith College central chilled water system. A majority of the campus’ core buildings get their air conditioning from a chilled water loop, generated by the central chilled water plant. The object of the project was to increase the efficiency of the chilled water system, saving energy costs and increasing building comfort levels.
Through a combination of system improvements in piping, metering and control sequences, chilled water, generated by the central plant’s three chillers, is sent only to the buildings that currently need to be cooled. This maximizes the cooling ability by reducing losses associated with the old system of sending chilled water through every pipe in every building. Now, buildings that are on the end of the chilled water loop are getting colder water, allowing for better space conditioning of the buildings.
During the implementation of the project, it became evident that the cooling towers, which are an important part of the system, were quickly nearing the end of their lifecycle. A decision was made to replace the aging towers with new, more efficient towers. While the old towers had an expected lifecycle of 15 years, the new towers are expected to last 40 years and will be able to handle any future expansion of the system, thereby saving potential costs and increasing system efficiency. Siemens had forecasted minimum energy savings of 38 percent for the new system. So far, savings have exceeded expectations, averaging around 45 percent.
The Demand Flow project demonstrates the commitment by Meredith College to decreasing our carbon footprint through equipment efficiency thereby decreasing electrical energy use, lowering costs, increasing comfort levels and being a good steward of both our environment and the College’s financial health. Savings from energy efficiency will further fund other energy conservation projects that continue to support Meredith’s commitment to sustainability. The project was a joint effort of the Meredith Facilities department led by Steve Walters, Associate VP for Business and Finance, the Aramark facilities management team, and Siemens.
—Submitted by Dave Lyons, Energy Manager