City of Chula Vista, CA: South Library Retrofit


The South Branch of the Chula Vista Library system was originally built in 1995. The single story structure was designed by Mexican architect Ricardo Legorretta as a mix of modern and 1950s traditional architecture, and features a stucco exterior. The property is typically open 50 hours per week, and in addition to normal library functions it provides child literacy programs, tutoring services, passport information, and serves as a County of San Diego Cool Zone for the community.



The following energy conservation measures were implemented:

  • Chiller replacement
  • Air handler upgrade and coil installation, including installation of two variable frequency drive (VFD) controllers for supply fans
  • Buildings automation controls replacement

While the new equipment is 40% to 50% more efficient than equipment replaced, the library's hours of operation increased from previous years, reducing some of the expected savings.


The project replaced an existing 100-ton TSI semi-hermetic, R-22 condensing unit with a 100-ton Trane CGAM air-cooled water chiller with factory mounted pumping package, chilled water coils and all associated piping, valves, and control components. Additionally, four direct expansion (DX) refrigerant air-handler coils and the dampers and control actuators were replaced due to the condition of the outside air (OSA) dampers and to facilitate access to and replacement of the coils. The 60-horsepower (HP) supply fan variable frequency drive (VFD) that controlled two, 30-HP supply fan motors had recently failed.  This VFD was replaced.

The interior flooring of the PACE air-handler’s mixed air plenum section was refinished and painted, and the insulation on the inside walls within the mixed air section was replaced. 

The existing Siemens System 600 Remote Building Controller (RBC) along with all Terminal Equipment Controllers (TEC’s) were replaced with a fully automated Trane Tracer SC Building Automation System.



The new control system allows for building schedule optimization, improving occupant comfort while reducing energy use. The upgrades have also reduced maintenance and repair costs. 


Annual Energy Use

(Source EUI)
Baseline (2012)
178 kBtu/Sq. Ft.
Actual (2014)
132 kBtu/Sq. Ft.

Energy Savings:


Annual Energy Cost

Baseline (2012)
Actual (2014)

Cost Savings:


Sector Type

Local Government


Chula Vista, California

Project Size

39,000 Square Feet

Financial Overview


South Chula Vista Public Library
South Chula Vista Public Library

Installing New 100-ton Air-Cooled Water Chiller
Installing New 100-ton Air-Cooled Water Chiller

Refurbishing Outside Air Inlet Dampers
Refurbishing Outside Air Inlet Dampers