Department of General Services State of California, Central Utility Plant Central Utility Plants

Central Utility Plant Project is a replacement project for an existing central plant. The plant is connected to twenty-three (23) state owned buildings, including the State Capital Building, and will serve over 5.5 million square feet of existing space, with added capacity for future expansion. The project was constructed on the downtown site of the existing plant, and is surrounded by both commercial and residential properties.

The mechanical systems were designed using a collaborative process of the mechanical engineer and Lawson Mechanical Contractors (LMC). LMC did a complete 3D-modeling of the mechanical pipe systems, coordinating with the other mechanical, electrical, and GC trades.  LMC’s mechanical Scope of Work included the fabrication and installation of the chilled water, condenser water and hot water pipe, the fuel oil pipe, installation of the contractor purchased HVAC equipment, and the on-site field erected composite cooling tower (under seperate contract with tower supplies).

The following are the mechanical system capacities of the central plant:

Cooling Capacity:

• Seven (7) Water Cooled Chillers 16,300 Tons Cooling (Total)
• Seven (7) Primary Chiller Water Pumps 3260 GPM; 60 HP ea.
• Six (6) Primary Chiller Water Pumps 3520 GPM; 200 HP ea.
• Seven (7) Condenser Water Pumps 6520 GPM; 200 HP ea.
• One (1) Eight Cell Composite Cooling Tower 19000 Tons Heat Rejection
• One (1) Chilled Water Storage Tank (by others) 4,000,000 Gallons

Heating Capacity:

• Four (4) Steam Boilers 221,000 LBS/HR @ 250 PSIG
• Two (2) Condensate Transfer Pumps 150 GPM; 10 HP ea.
• Two (2) Condensate Transfer Pumps 400 GPM; 25 HP ea.
• Two (2) Boiler Feed Water Pumps 200 GPM; 75 HP ea.
• Two (2) Boiler Feed Water Pumps 75 GPM; 40 HP ea.
• Two (2)Heating Hot Water Pumps 650 GPM; 7.5 HP ea.

Miscellaneous:

• One (1) Steam Turbine Genrater 43,000 LBS/HR; 3625 KVA

The Central Utility Plant had many complex conditions that created chanllenges during the design and
construction. These issues included the following:

• Design new plant on existing downtown site and address the issues associated to property line sound
  levels.
• Cooling Tower Plume Impact
• Existing Distribution Pipe Tie-in’s