Central Energy Facility

This plant was established to develop a district cooling system to serve downtown Houston.

The plant was designed and constructed on an accelerated fast track basis.  Shah Smith & Associates Inc. quickly programmed the plant requirements and design parameters, then issued proposal requests for all major equipment while the plant schematic design was being prepared.  Using novation agreements, the equipment contracts were assigned to a General Contractor at a later date.  Partial design releases of civil and foundations prior to completion of the full plant design allowed further acceleration of the project.  The project was designed, constructed, and placed into operation in 18 months, cutting almost a year off the normal design-bid-construct process.

SSA designed the plant to serve a peak load of 33000 tons, using five 2000 ton centrifugal chillers, five 2500 ton screw chillers, and ice water from an 88,000-ton hour ice storage system. The plant has numerous creative concepts to increase efficiency and reduce the cost of the delivered chilled water.

Evaporative condensers were used with the screw chillers to minimize condensing pressure and increase efficiency.  Dual evaporators were provided, one for chilled water and one for glycol, to allow the screw chillers to provide double-duty for greater efficiency and productivity.  Water chillers are operated in series with the ice storage to produce chilled water at 34˚F, allowing the load to be served with significantly less flow.  This reduces the size of distribution piping and pump energy consumed.

Dual 35 KV feeders provide redundant power to assure reliable service.  The plant has an industrial control system, designed to monitor and control all equipment and systems in the plant.  The control system was designed to connect to the additional chiller plants which will be constructed in the future, allowing all facilities to be operated from one location.

SSA was honored for the opportunity to design of one of the largest, most efficient central plant projects constructed in the Houston area in 1999.