By Matthew Tunnard
April 8, 2010
There is an inarguable spotlight on sustainability right now with an emphasis on the flashier items such as solar power or wind turbines. Consequently, building owners often do not realize that the greenest solution is right under their nose. Existing building commissioning (EBCx) has a proven track record to reduce energy costs for facilities with a relatively short payback.
The importance of EBCx has increased due to the slowdown of new construction and the practice of reinvesting capital into current assets to make the space high-performing, comfortable, robust and cost-efficient. As money is tight, owners are focusing more on consumption and ways to decrease their building’s hunger for energy. Further, making adjustments to spaces (e.g., open air office, rather than cubicles) can create a more soothing environment that fosters occupant satisfaction and retention.
Currently in the United States, approximately 5 percent of existing buildings have been commissioned. Based on a 2009 study of 643 buildings by Evan Mills of the Lawrence Berkeley National Laboratory (LBNL) commissioning resulted in an average energy savings of 16 percent. These energy savings are rarely found with one or two major issues, rather a whole series of issues that together amount to significant savings. The highest energy wasters are items such as proper scheduling of HVAC and lighting systems, air balancing, dampers and valves operating properly and not leaking, and controls systems. An EBCx program will check all of these systems and put them back in proper operating condition.
Case studies conducted in-house have found the same results:
-¢ Commissioning services saved over a quarter million dollars in utility costs within the first year at Allen Park Public Schools in Michigan.
-¢ EBCx at four schools in Michigan saved an estimated $52,000 per year for a $0.26 per square foot energy savings.
What is an EBCx program? According to the Building Commissioning Association, “EBCx is a systematic process for investigating, analyzing, and optimizing the performance of building systems through the identification and implementation of low/no cost and capital intensive Facility Improvement Measures (FIM) and ensuring their continued performance.”
EBCx has become a popular tool to identify potential problems and rectify ongoing problems within buildings. Other purposes of EB-Cx include:
-Improve building performance to save on energy costs,
-Reduce complaints and increase tenant comfort and satisfaction,
-Minimize operational risk and increase asset value,
-Extend equipment life,
-Reduce liability associated with poor environmental quality.
EBCx is accomplished through five main phases.
Planning Phase
The owner and EBCx provider review the current facility requirements, which include changes to the building from original design. Together, they develop operating requirements such as temperature, humidity, operating hours, and any specialty needs the space may have.
Investigation Phase
The provider will physically check the building systems. They will interview facility staff, review utility bills, check control systems, and perform some trending analysis to evaluate the building condition.
Implementation Phase
During this phase, the provider analyzes and prioritizes the FIM for implementation. The FIM will show a project return on investment, implementation cost, and simple payback. After the FIM have been implemented the team will evaluate the systems by retesting to ensure successful completion of the FIM. Measurement and verification of utility savings may also be executed at this time.
Turnover Phase
Operation and maintenance manuals are updated and systems manuals are developed showing the updated sequences of operations. Training of staff is provided so they understand the changes. Final reports are created and delivered along with plans for the building owner to maintain the systems.
Persistence Phase
The final phase is for the building owner to maintain the improved efficiencies through routine testing, tracking energy use and key building parameters.
For commissioning to be successful, all stakeholders must be active participants, including senior management, engineering, O&M staff, contractors, vendors and occupants. The objective, third-party CxA coordinates the process and provides technical expertise necessary to ensure a successful and thorough project. Commissioning by a credible independent CxA can provide owners with peace of mind that deficiencies were uncovered and corrected in the most cost-efficient manner.
With industry organizations working to standardize the process and coin an easily understood name, clarity has improved. Looking at these systems with eyes wide open can help resolve a multitude of issues and reduce green house gas emissions and pollution more so than any other means available. Overall, EBCx has the ability to save $30 billion in energy savings alone, by 2030. This equates to approximately 340 megatons of CO2.
Existing building commissioning is truly a sustainable building practice and is a strong solution for owners who desire to secure the best ROI and performance for their buildings, while helping our nation reach its ever growing green goals.
References: Building Commissioning: A Golden Opportunity for Reducing Energy Costs and Greenhouse Gas Emissions, Evan Mills, Ph.D., Lawrence Berkeley National Laboratory, July 21, 2009, http://cx.lbl.gov/documents/2009-assessment/LBNL-Cx-Cost-Benefit.pdf
The Building Commissioning Association, Best Practices in Commissioning Existing Buildings, August 18, 2008 http://www.bcxa.org/downloads/bca-ebcx-best-practices.pdf
Matthew Tunnard, PE, CCP, LEED AP is with the Houston office of Horizon Engineering Associates and has over 15 years of experience in the leadership and performance of commissioning, design, and operational consulting services for both new construction and renovation of facilities.
