Two Union Square – Chiller Plant Retrofit
Seattle, Wa
Two Union Square was completed in 1981, and with today’s need for efficiency, Washington Holdings requested a plan for a new chiller plant.The main objectives were to design a highly efficient plant with redundancy and the ability to add chilled water plant tonnage in the future. MacDonald-Miller designed a plan using common headered piping on both the condenser and chilled-water systems; the idea is that any pump can be used with any chiller or cooling tower. Additionally, the headered piping and pumps were upsized with the ends of the headers capped for a future additional 350-ton chiller, if heat loads increase in the future. Research determined that (3) 533-ton York YMC2 magnetic bearing chillers met the energy efficiency, sustainability and dependability parameters. The next step was to determine how to install chillers on the 57th story without external lifting devices. The answer was to break down the chillers into pieces and hoist them to the 57th story using the building’s freight car.