• 5101 Wisconsin Avenue NW, Suite 400, Washington, DC 20016

Wilbur J. Cohen Building – Cooling Towers

Construction of the Cohen Building was completed in 1939. The building has five stories plus a penthouse and one story below grade. The gross area is 1,047,677 square feet. Seven Carrier Chillers each rated 2,100 kW, seven pumps and fourteen cooling towers, composed the original cooling system. Around 1971 the original cooling towers were replaced with 12 Units. In 1998 the Chillers, chilled water pumps and condensing water pumps were replaced and the system capacity was reduced based on a calculated reduced building load. The towers were not replaced as it was considered at that time that they were in good condition and were oversized to manage the new reduced load.

In this project JVP Engineers, P.C., investigated the existing installation and designed the replacement of the twelve existing cooling towers in the penthouse of the building with new towers sized accordingly with the chillers and pumps and improving current conditions, which include leaks, plume formation and short-circuiting of the discharge air into the air intakes creating health hazards. The new towers are oversized by 20% compared to the chiller capacity to compensate for derating and a load increase in the future. The tight condition of the space where the towers are located (enclosed in the penthouse level) and the historic preservation requirements for the roof of the building were factors that influenced the design. Since the new towers are larger than the ones being replaced and the disadvantage of having enclosed towers which increases dramatically the power requirements, the design was to enlarge the existing discharge openings on the roof to permit the installation of towers in the penthouse level that protrude through the roof thereby reducing the power requirements and modifications to the power system. Electrical Engineering design services included replacing the existing motor controls centers and providing electrical power to the mechanical equipment. The controls for the new cooling towers were integrated to the building central control system.

 

Construction date: 2004
Location: Washington, DC
Project Cost: $2.3 million