The 21,000-sq-ft central utility plant (CUP) is the first phase of a major overhaul to an aging county hospital campus that primarily serves underprivileged and uninsured patients in Maricopa County. Completed in September 2020, the CUP was built inside a functioning 40,000-sq-ft data warehouse by incorporating a steel-skeleton superstructure designed to allow construction within existing facilities.

Just getting the plant’s massive equipment into the warehouse was challenging. Crews cut into the side of the building to deliver three 2.5-MW generators as well as the 30-in. condenser main that links the cooling tower and the chillers. They also built a new roll-up door for the plant’s five 1,500-ton chillers. The plant includes two 20,000-gallon diesel fuel tanks and five boilers, each with an output of about 5.4 million BTUs. Also included are 10 gas-fired boilers, emergency generators, a 40,000-gallon fuel-oil tank system and 600-amp medium-voltage generators.

The steel superstructure is designed to accommodate another chiller, generator and two more boilers, enough equipment to power a second hospital tower, if needed.

To avoid disrupting hospital operations, traffic patterns were changed, and the utility shutdown plan was modified to be carried out at night. The team brought in generators to provide power during the brief shutdowns.