Central Energy Plant
MultiCare Health Systems
Tacoma, WA

Tacoma General Hospital’s 50-year old Central Energy Plant was in need of an upgrade to increase efficiency, meet the demands of the hospital, and accommodate anticipated growth. The existing plant distributed Steam, Condensate Return compressed air and emergency power to 16 buildings throughout the hospital campus.

Wood Harbinger provided mechanical and electrical engineering and construction administration for a sustainable, economical, and efficient stand-alone facility that provides a safe work environment and an improved quality of service to the MultiCare patients and staff. The new central plant was moved from the existing building to a new site to enable room for future expansion.

The new steam plant’s two high-efficiency 40,000 lb/hr boilers and one 20,000 lb/hr boiler operatee with a minimum of 20% greater efficiency compared to the old plant, reducing the fuel cost and fuel demand for the hospital. Three 1.5 MW – 12.47 kV emergency generators are connected to new 15 kV paralleling switchgear integral with a double-ended 15 kV utility service switchgear. This installation serves hot bus backup for both normal and emergency medium voltage campus and hospital distribution.

Together, the new plant delivers cost-effective steam and emergency power to the medical campus, and with space for a future large boiler and a fourth emergency generator, it is designed to accommodate the hospital campus’s needs through the year 2049.

This facility also contains 80,000 gallons of back-up No. 2 fuel oil, a new medical gas tank farm, a 175 psig compressed air system that will be used for both fuel oil atomization and shop air, shop area for the hospital’s maintenance staff, spare parts and hazardous material storage areas, conference room, control room, and supervisor’s office.

The selected location for the new central plant next to the historic Wright Park sparked community concern regarding Exhaust drifting from the boiler exhaust stacks over to the park. Wood Harbinger performed a Computational Fluid Dynamic (CFD) analysis of the boiler exhaust stacks to determine the appropriate height of the stacks to prevent discharge into the adjacent or future planned medical buildings and the trees of the adjacent park.

In addition, the location prevented the reuse of much of the existing distribution system; Wood Harbinger provided design for a Tunnel/Utilidor system that would maintain service to all existing facilities while providing future tie-in locations based on the hospital’s 50 year Master Plan. The routing of the new distribution system, with total length approaching 1,000 feet, relied heavily on utilizing city streets due to lack of open space throughout the campus.