Retrofitting, retro-commissioning (RCx), and recommissioning commercial buildings to cut energy are on the rise, and for good reason.
Building, as it turns out, is bad for the planet.
Commissioning? Retro-Commissioning (RCx)? Recommissioning? A Glossary of Terms
Building commissioning: When a new building is initially commissioned it undergoes an intensive quality assurance process that begins during design and continues through construction, occupancy, and operations. Commissioning ensures that the new building operates initially as the owner intended and that building staff is prepared to operate and maintain its systems and equipment.
Retro-Commissioning (RCx) is the application of the commissioning process to existing buildings. It is a process that seeks to improve how building equipment and systems function together. Depending on the age of the building, retro-commissioning can often resolve problems that occurred during design or construction, or address problems that have developed throughout the building’s life. In all, retro-commissioning improves a building’s operations and maintenance (O&M) procedures to enhance overall building performance.
Recommissioning is another type of commissioning that occurs when a building that has already been commissioned undergoes another commissioning process. The decision to recommission may be triggered by a change in building use or ownership, the onset of operational problems, or some other need. Ideally, a plan for recommissioning is established as part of a new building’s original commissioning process or an existing building’s retro-commissioning process.
The commissioning of a new building isn’t mandatory in every state, and in those where it is, it’s a relatively new development. For example, California’s 2019 Energy Code now mandates commissioning for buildings over 10,000 square feet. U.S. Federal agencies started earlier, requiring “Total Building Commissioning practices” of their buildings’ systems, regardless of state, since 2006. But even buildings that have been previously commissioned were not always designed for energy efficiency.
Many municipalities offer rebates for retro-commissioning, which makes it even more attractive. Building owners get paid for the kilowatt hours they save. Rebate amounts and qualification criteria vary. Rebates make retro-commissioning a “no-brainer,” according to energy efficiency experts.
Jim Schafer, Project Services Energy Director for PRIDE Industries, notes, “The original building design, prior to the 2000s, typically wasn’t energy efficient, as most architects weren’t focused on energy efficiency then. It wasn’t their area of expertise or focus, so many didn’t fully understand energy-efficient design.”
When to Recommission or Retro-Commission?
The U.S. Department of Energy recommends that buildings are recommissioned at “about the 3-5 year point since the previous commissioning.” In instances where a building has never been commissioned, initial retro-commissioning can take place at any time—the sooner after initial construction, the better.
What Does Recommissioning/Retro-Commissioning Take into Account?
These assessments and processes delve into HVAC, building automation, building enclosures, water, lighting, control strategies, and operations sequencing—separately and as these systems work together in varied conditions.
“To get a better, more in-depth understanding of how the different systems respond to different conditions,” says Shafer, “a good RCx will use functional testing, trend logging of HVAC systems, and data logging of the electrical system.”
A recommissioning/retro-commissioning team will also be informed about rebates and incentives offered through state and county agencies.
What’s the Process?
For both recommissioning and retro-commissioning (RCx), the process typically involves four steps:
- Planning – Objectives are set. A building’s operational requirements are identified and documented. A walk-through is performed. Trouble spots are discerned. A written plan is created. A team is assembled.
- Investigation – Building/facility documentation is reviewed. Intended purposes and functions for building’s systems are identified. A list of findings is created. Diagnostics and testing are performed. Operational improvements are prioritized. Recommendations are made. Simple repairs are made.
- Implementation – An implementation plan is developed. Identified operational improvements are implemented, including repairs, replacements, and building revisions. Results are verified and documented.
- Handoff – A final report, a systems manual, and a recommissioning or retro-commissioning plan is developed. Training is provided to operations and maintenance personnel. The building is formally returned to service through a close-out meeting.
What’s the Payoff?
- Cost Savings
- Increased ROI
- Improved System Efficiency
- Improved Energy Efficiency
- Improved Reliability
- Decreased Waste
- Greater Comfort for Building Inhabitants
- Smaller Carbon Footprint
- Qualification for Rebates and Incentives
A study by Lawrence Berkeley National Laboratory (LBNL) underscores these benefits. The lab studied 643 commercial buildings, finding that the retro-commissioning (RCx) process was “compelling” when it came to energy and cost savings. RCx resulted in a 16 percent median whole-building energy savings for existing buildings with a payback time of 1.1 years. Further discovered cost benefits included cash-on-cash returns of 91 percent—all while helping the planet.
Retro-commissioning’s benefits are so compelling, in fact, that our nation’s Capitol has gotten on board. RCx has contributed to a 48 percent building-related drop in greenhouse gas on the Capitol campus.
In general, facilities managers are always looking to do more with less, and even more so when inflation and energy prices are on the rise. Retro-commissioning is a cost-effective, high reward step managers can take to improve energy efficiency.
“I’ve been doing RCx and Performance Contracting for over 30 years,” says Schafer, “with many projects guaranteeing savings. Understanding the cost benefits to energy savings ratio is key to a positive ROI—especially given the current economy.”