Commissioning (Cx) is a systematic process to ensure that new building systems perform according to design intent and operational needs. As such, recommissioning (Rx) is the process of reviewing existing equipment and systems to meet these same objectives, and it can be a highly effective way to meet facility performance goals by reducing operation and maintenance costs and cutting energy consumption.
Despite these benefits, most buildings have never undergone recommissioning. Often, this is because upper management does not fully understand the advantages of this process.
Recommissioning was first created to ensure that HVAC systems were installed and operated correctly within the original design specifications. Today it often extends to other systems, such as lighting, plumbing, electrical, or the building envelope.
Facility managers can make a strong business case for recommissioning based on evidence that it is a highly cost-effective way to achieve financial and building operating performance outcomes. A December 2004 study of 224 recommissioned buildings, conducted by the Lawrence Berkeley National Laboratory (LBNL)—“The Cost-Effectiveness of Commercial-Buildings Commissioning: A meta-analysis of Energy and Non-Energy Impacts in Existing Buildings in the United States”—found that recommissioning achieves a median of 15% energy savings, with potential payback periods of less than a year. Many buildings realize even greater cost savings.
Recommissioning also achieves other important outcomes, such as improved indoor comfort and air quality, lower operation and maintenance costs, greater occupant satisfaction, extended equipment lifetime, safety benefits, and better overall operating performance.
Even armed with research data to make a strong business case for a recommissioning investment, a facility manager may find it difficult to approach the topic with higher-ups, especially if such a project might put a focus on inefficiencies caused by deferred or improper maintenance. However, it is important to realize that even well maintained buildings can fall out of specification, since routine maintenance only addresses individual pieces of equipment. Recommissioning focuses on keeping a building’s total system operation at the design specification levels required to meet building performance goals.
Emphasize cost benefits. When proposing recommissioning for a facility, the facility manager can point out that, although spending may be reduced in the short-term through deferred maintenance, this can be extremely costly in the long run. A commissioning engineer will quantify the costs and risks of deferred maintenance and the cost benefits of system improvements.
All buildings can benefit from recommissioning, but the more energy intensive the facility the greater savings it will achieve. The LBNL study found that the outcomes with the highest returns on investment occurred in facilities with large energy demands, such as hospitals and laboratories.
Point out productivity gains. In addition to energy savings, recommissioning leads to financial returns in increased occupant comfort and productivity. Ergonomics studies, such as 2004 research by Professor Alan Hedge, Ph.D., CPE of Cornell University in Ithaca, NY—“Linking Environmental Conditions to Productivity”—show that better indoor environment conditions, including sound, lighting, air quality, and temperature, lead to higher worker productivity. Recommissioning can lead to improvements in all of these areas, thereby improving occupant performance and financial outcomes.
Funding options. Facilities that do not have capital to invest can consider performance contracting, which develops solutions to package “fast payback” improvement initiatives with building infrastructure projects that may have a longer payback period. For example, K-12 schools, which often have limited budgets, coupled with a substantial need for system improvements, typically achieve excellent results through performance contracting.
When embarking on the recommissioning process, there are several steps the facilities management staff should follow:
Choose a project leader who understands the facility. It is essential to find the right person to conduct the recommissioning project for the facility. If the expertise does not exist on the facility staff, an independent commissioning agent or qualified HVAC service provider should be hired.
The recommissioning engineer must not only have the right technical expertise, but also must understand the objectives of the facility and make a commitment to help reach those goals. Communication throughout the process is critical to ensure that recommissioning actions remain in line with management expectations.
Assess original design and current operations. A recommissioning project will begin with the assembling of all available information from the original building and systems design and commissioning, including plans, specifications, drawings, and equipment manuals.
Next, the commissioning engineer conducts a complete survey of the building systems’ conditions and operations.
The initial assessment also involves analysis of the building’s current operational needs. Depending on the facility’s size and complexity, this may take weeks to several months to complete.
Conduct a gap analysis. Once design intent and current conditions are assessed, the commissioning engineer conducts a gap analysis to identify problems, inefficiencies, and potential improvements. The results of the evaluation are compared to the original design intent of the building and the current demands. The project might identify an array of issues, ranging from high utility costs, energy inefficiency, and occupant complaints to system failures and health and safety risks.
Prioritize actions. The commissioning engineer should then work with the facility manager to prioritize the issues, conduct a cost analysis, and decide on which improvements to make. Recommendations might include small adjustments that can achieve significant savings or retrofitting projects. Investment decisions are based on the best and most cost-effective ways to reach the objectives.
Train staff. Recommissioning often provides rapid payback, but long-term savings require staff training in order to uphold the benefits of systems improvements. A preventive or predictive maintenance program should be put in place to ensure the best results for many years to come.
Implement continuous commissioning. Once the systems have been recommissioned, facility managers will want to sustain the benefits through an ongoing process of reviewing the operation of systems and equipment to assure that they continue to operate at maximum efficiency.
Ultimately, by proposing recommissioning, a facility manager can demonstrate interest in achieving better financial results and performance outcomes for the building.
Vorwald is measurement and verification manager, Americas and Services Contracting (ASC), for Trane. He has more than 20 years of experience as a mechanical/project engineer in the building automation systems and energy conservation fields. He has been certified by the Association of Energy Engineers and holds a bachelor’s degree in Mechanical Engineering Technology from Purdue University, and a Master of Arts in Organizational Management from the University of Phoenix.