Benefits of Retro Commissioning

by Charles Hutchinson, Irvine, Commissioning Agent

In the fall of 2007, Glumac was selected to participate in the retro commissioning process for the First American Corporation Campus located in Santa Ana, California, for the PECI Retro Commissioning Program.  The focus of this program was to look for low cost improvements with short paybacks.  The tasks included equipment assessment through visual inspection, analysis of system data through the building management system and portable data loggers, compilation of all findings, implementation of selected measures, verification of implemented measures, submission of a final report and training for the Owner.  This process took almost two years to complete.  The benefits included improved building performance, reduced energy usage and carbon emissions reduction. 

The campus consists of five multi-story office buildings, each of which operates independently of one another.  There is a campus-wide building management system that controls and tracks equipment usage for all buildings.  Three of the buildings have packaged rooftop air conditioning units, and the other two buildings have air handlers with chilled water coils served by individual chiller plants in each building.  Hot water is circulated through coils at perimeter variable air volume terminal boxes for heating.  Each building has its own hot water boiler and circulating pump.

The initial assessment included a visual inspection of the equipment and operating conditions of the buildings, interviews with building operating staff and functionally testing some of the systems.  Trends were set-up to monitor different building attributes.  After analyzing the trend data along with the site inspection, a total of 48 issues (or findings) were documented that would improve the operating efficiency of the campus.  After numerous reviews by PECI, the Owner and a third party firm, 15 of the findings satisfied the payback period requirements.  Other findings such as broken dampers, defective sensors, etc. could be corrected under a separate scope of work, and correction of these items could improve the buildings' efficiency.

The findings that were discovered were similar throughout the five buildings and included issues such as lower than required supply air set points, simultaneous heating and cooling allowing chiller and boiler operation at the same time, a high boiler lockout temperature which had the boiler and pump operating even when it was 85 degrees F outside and after hours equipment operating when the buildings were not occupied.

Each finding was documented to PECI and the Owner in our report.  Associated implementation costs and payback periods were provided for each finding, and the average payback period was calculated at less than one year.

The Owner then moved forward with the implementation phase.  Glumac provided a scope of work document to the Owner who then had contractors bid on the scope of work.  A controls contractor, familiar with the building, was selected to implement the improvements and worked closely with Glumac.  The Owner now has the controls contractor under a service contract to provide monthly maintenance and system upgrades, ensuring that the implemented measures remain long term.

Once all measures were implemented, Glumac reviewed the buildings' operation again to verify that all items were corrected.  Savings calculations were also reviewed and updated based on trend data.  A final report was submitted and approved by PECI and its third party reviewer, and Glumac provided a training and information session for First American Campus personnel based on the report.

The results of the program were a reduction of approximately 470 kilowatt hours of annual electricity and 6,200 therms of annual natural gas consumption.  This translates into increased equipment life, improved building performance and a carbon footprint reduction of 230 tons for the First American Corporation Campus.