This detention facility, located in the California High Desert area, undergoes substantial temperature extremes, from a measured high of 122°F to a measured low of 13°F.  When ROI was retained to act as the owners Mechanical Systems Architect, the mechanical design was already completed.  The owner reviewed the design, and determined that they wanted a system that could substantially reduce the expected operating cost of the facility.

Working as a part of the Team, we were able to educate the Architects design team on the benefits of thermal energy storage, and on the Large Temperature Differential (LTD) design strategies that  we had employed on other projects.

There was approximately one mile of piping on the project, and the conversion of a system using a 12°F temperature differential to a system using a 30°F temperature differential dramatically reduced the size of the piping, pumps, variable speed drives and other appurtenances associated with the chilled water distribution system. 

In addition to the TES system benefits of using an LTD approach, the high return water temperatures during the summer (70°F to 73°F) allowed the cost effective use of a cooling tower and plate and frame heat exchanger system as a “hydronic economizer” to pre-cool the warm return water prior to entering the chiller system.  For most of the year, the cooling tower and plate and frame HX can act as a 1,000 ton chiller, operating at approximately 0.10 kW per ton.

The use of the hydronic economizer and TES system allowed us to eliminate the need for maintenance prone airside economizer systems on each of the 50+ AHUs on the site.

The cost savings from the smaller piping infrastructure and the elimination of the economizers and controls from the AHU’s, coupled with the utility incentive, combined to completely eliminate the first cost impact of the TES system.

This project won an award in the Southern California Edison Design For Excellence energy efficiency competition, as well as an award from ASHRAE, Southern California Chapter.

This TES system uses 30% less energy than a typical central plant facility, making it the most energy efficient TES system on the Southern California Edison utility grid.

Challenger Memorial Youth Center | 400/600 Corporate Point
Jamboree Center | McArther Court