Best Practice Guide

Commercial Office Buildings

Planning an Energy Program

Energy Audits

An energy audit first identifies how energy is used in a facility, and then recommends ways to improve energy efficiency and reduce energy costs. In practice, there is wide variance among the different levels of energy audits available. Or, as Albert Thumann writes in the Handbook of Energy Audits, "There is a direct relationship to the cost of the audit (amount of data collected and analyzed) and the number of energy conservation opportunities to be found."

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) identifies three levels of energy audits:

  • Walk-through Assessment: energy bills are analyzed and, possibly, a brief visual survey of the facility is conducted. The subsequent report identifies no-cost and low-cost opportunities. This is the least costly of the three levels.
  • Energy Survey and Analysis: a more detailed analysis is conducted, including a breakdown of how energy is used within the building. Recommendations consider an owner's operations and maintenance, constraints, and economic criteria. Potential capital-intensive opportunities are identified in the final report for further research and analysis. This is the typical level of audit.
  • Detailed Analysis of Capital-Intensive Modifications (Investment-grade Audit): this analysis focuses on capital-intensive opportunities and provides a higher degree of monitoring, data collection, and engineering analysis. The report includes detailed cost and savings information with a high-level of confidence sufficient for major capital investment decisions, and may include a reasonable timeline for implementation of each recommendation.

Local utilities are valuable partners for energy audits. The utilities can arrange for one of their engineers to assist with an energy audit or can recommend third-party providers in your area. The utilities also have testing equipment, such as portable meters and diagnostic software, that in-house facility staff can use to conduct an energy audit. Check with the local water agency, too, to see if they provide water audits - integrating energy-related and water-related upgrades into one action plan provides additional cost savings with the least amount of disruption to workers and building occupants.

Remember that certain problems only occur during a particular time or season. Time energy audits accordingly. For example, if you decide to upgrade chiller equipment that underperforms in warm weather, be sure to schedule the energy audit during summer months so that engineers can test it in the appropriate conditions.

Business Examples

Cypress Semiconductor in San Jose undertook an investment-grade energy audit, focusing primarily on the HVAC system. Ferreira Service Inc. (FSI), a heating, ventilation, and air conditioning (HVAC) engineering specialist, conducted the audit by monitoring and analyzing real-time operations for two-and-a-half months. The trend- and data-logging resulted in more than 70 recommendations to improve energy efficiency, none of which required major equipment investment. Facility staff at Cypress evaluated the recommendations based on Cypress' internal investment criteria, then worked with FSI to implement those strategies that made financial sense. The results were astounding. First-year energy savings were 881,552 kWh (55 percent reduction) and 73,590 therms (85 percent reduction), saving Cypress about $150,000. Payback on investment in the energy audit was less than one year.

Glenborough Realty Trust recognizes that one of its most important responsibilities is recruiting reliable, trustworthy, and competent partners. In particular, Glenborough seeks experienced contractors to conduct detailed energy audits and then report on their findings in a way that is simple and easy to understand. One such partner, Servidyne Systems, Inc., customizes ENERGY STAR commercial building tools specifically to suit Glenborough's needs.


Resources

Flex Your Power information on Audits, Classes, and Services

U.S. Department of Energy, Energy Efficiency and Renewable Energy, Energy Audits: Reading List

Thuman, A., PE, CEM and Younger, W.J., CEM. Handbook of Energy Audits, Sixth Edition. Fairmont Press, 2003.

Pacific Gas and Electric, Energy Audit by Experts.

Pacific Gas and Electric, Pacific Energy Center, Tool Lending Library has thousands of measurement tools available for short-term energy projects like in-house energy audits.

Southern California Edison, Online Energy Survey