Retro-commissioning, or RCx, focuses on finding operational and maintenance improvements that can be made to boost an existing building’s performance. Oftentimes, changes are low-cost and easy to make, said Dan Bulley, senior vice president of the Mechanical Contractors Association of Chicago.
“And they can lead to significant cost-savings,” said Bulley, whose organization represents contractors who are often called upon to provide the expertise and the equipment necessary for projects suggested by a retro-commissioning study.
The foundation is commissioning, according to the Smart Energy Design Assistance Center, or SEDAC.
Commissioning is the process for new buildings of ensuring systems are designed, installed, tested, and deemed capable of being operated and maintained according to the building’s needs.
Re-commissioning is when the process is applied to a building that has previously been commissioned, usually done every three to five years to maintain optimal operations and performance.
Retro-commissioning, or “RCX,” uses the same process, but is applied to existing buildings that have never been commissioned. It also is more intensive than an energy audit, SEDAC officials say.
“RCX offers many benefits to those who follow through with the recommendations,” according to SEDAC. “By increasing the operational efficiency of the building, facilities that complete the process receive lower energy bills, and often require fewer service and maintenance calls.
“Further, increased efficiency extends equipment service life, increases property value and usually creates a more productive and comfortable facility.”
Jessica Commins, SEDAC program manager, said the public entities seeking assistance from SEDAC usually see payback within six to eight months. The minimal investment SEDAC requires for the free analysis the agency offers for public buildings in Illinois is $10,000.
“Retro-commissioning helps building owners make some simple tweaks to save some tremendous money,” she said.
LEED-ing the wayRetro-commissioning is becoming more and more popular, especially with more building owners working to obtain Leadership in Energy and Environmental Design for Existing Buildings, or LEED-EB, said Chris Toman, commissioning and start-up manager with Hill Mechanical Services in Franklin Park, Ill. The contractor offers commissioning, re-commissioning and retro-commissioning services.
The LEED-EB certification process, administered by the U.S. Green Building Council, rewards buildings that undergo an existing building commissioning. The points fall under the energy and atmosphere category of the certification. Other categories include sustainable sites, water efficiency, materials and resources, indoor environmental quality and innovation in operations.
While all ages of existing buildings can be retro-commissioned, the most common are those that are 25 to 40 years old, Toman said.
For a retro-commissioning, experienced personnel analyze the building, devise a list of projects and provide an estimate of cost savings.
“The payback,” Toman said, “is usually very good. It’s usually one- to three-years, an inexpensive way to get to low-hanging fruit of energy savings.”
One of the most common projects – a project that also comes with a sizeable payback – is a duct static reset, which saves energy by adjusting air flow inside of HVAC ducts, Toman said.
According to the Lawrence Berkeley National Laboratory, commissioning the stock of U.S. non-residential buildings would create a yearly energy-savings potential of $30 billion by the year 2030. It also would decrease annual greenhouse gas emissions by about 340 megatons of carbon dioxide each year.
The laboratory boasts the largest pool of research regarding commissioning. Its Hall of Shame showcases real-world examples of problems found in buildings: an exhaust fan hardwired always-on, rust as a symptom of poor anti-condensation heating control setpoints in a supermarket, air leakage in an underfloor air-distribution system and a hot water valve motion impeded by piping, among others.
With the economy often eliminating the option of building new for companies, retro-commissioning provides a chance for building owners to cut costs and bring new life to an older building.
“We are looking forward to seeing significant growth in the number of building owners pursuing retro-commissioning,” Bulley said. “The benefits are just simply unmistakable on many levels.”
(This article was supplied by Mechanical Contractors Association of Chicago.)