Smaller chilled water plants can be the most challenging for retrofit design, from both an architectural and an engineering standpoint.
The site was compact with limited space for expansion. The masonry walls supporting the cooling towers were failing, and the site lacked adequate security to ward off vagrants and vandals. The service entrance switchboard feeding the plant was outdated and mixed with feeders serving adjacent buildings. All chilled water system components had to be replaced during the peak of Phoenix summer, with no long-term power downtime for adjacent buildings and central plant cooling infrastructure. The site also required a new service entrance.
GLHN worked closely with ADOA project management and facilities personnel to plan a sequence to limit downtime in power and cooling capacity to only an hour during non-business hours. We planned the demolition of the existing masonry cooling towers and designed a new cooling tower yard. Two new state of the art cooling towers are placed on steel piers for easy access and serviceability. A new, aesthetically-appealing fence provides security, while masking the plant infrastructure and blending with the context of the site and neighboring buildings. The demolition of the masonry towers created a new pathway for the installation of a parallel set of feeders from the main transformer secondary to feed the new switchboard, while keeping the existing switchboard energized as long as possible prior to switchover.