Bring Your Buildings Back With Retro Commissioning

12/28/2022

Buildings are complex machines. When they’re shiny and new and everything is running great, facility managers feel like the kings or queens of the world. But it doesn’t take long for that luster to wear off. 

Things start falling out of spec. A damper is stuck open. An engineer overrode a setpoint and didn’t tell anyone. An occupant props a window open. A BAS module crashes and doesn’t reset. And these are just the tips of the icebergs. Yes, buildings are complex machines and lots can go wrong. 

This is why it’s crucial to periodically review a building’s energy-using systems to ensure, first, that they’re running as intended, and secondly, that they’re optimized for maximum energy efficiency and occupant comfort. This is what’s known as a retro commissioning process. 

The Environmental Protection Agency reports retro commissioning can save up to 15 percent on energy and with a payback of less than a year. As one prominent example, an ongoing project at the Capitol campus in Washington, D.C., with a stated goal of reducing energy use by 50 percent by 2025, saved “conservatively between 5 and 10 percent” in real-world energy use with a recent retro commissioning project.  

To start a retro commissioning project in your building, the first step is to identify the major energy-using equipment. It’s often helpful to bring on board a commissioning expert to ensure the most savings. We recently talked to once such expert, Rock Ridolfi, director of project operations for consulting firm Rivion, about commissioning, its importance, and the potential savings. 

FacilitiesNet.com: For facility managers, why is retro commissioning such a crucial strategy for re-harmonizing a building and saving energy? What savings are possible? 

Ridolfi: EPA recently published a report highlighting the major drivers of high energy performance and it shouldn’t be a surprise that the majority of the impact is driven by operations and maintenance (69 percent). Building teams must better understand what, where, and how to make their buildings perform better if they have any realistic opportunity to achieve their specific carbon, energy, water, waste/recycling reduction goals, or even carbon neutrality. If building energy performance is really 69 percent driven by O&M procedures, it makes the most sense to examine specifically which systems are consuming the most, when they are operating, and why. Retro commissioning is a great first step in how teams can go about correcting the most basic of O&M concerns. 

FN: Can you describe monitor-based commissioning? Why is this also an important part of an energy saving strategy? 

Ridolfi: I feel the main goal for monitor-based commissioning (MBCx) is simply creating a formal action plan to maintain better oversight and performance tracking on a more frequent basis. Implementing MBCx plan enables teams to react faster to variations in building performance. When teams can react faster or allow a software to identify anomalies, they may enact solutions which may reduce or eliminate consumption outside of standard usage patterns. Deploying fixes relatively immediately, not just waiting for the next utility bill to highlight a past concern. 

From LEED v4.1, the requirements to achieve the credit include: 

Develop monitoring-based procedures and identify points to be measured and evaluated to assess performance of energy- and water-consuming systems. Include the procedures and measurement points in the commissioning plan. Address the following: 

• Roles and responsibilities; 
• Measurement requirements (meters, points, metering systems, data access); 
• The points to be tracked, with frequency and duration for trend monitoring; 
• The limits of acceptable values for tracked points and metered values (where appropriate, predictive algorithms may be used to compare ideal values with actual values); 
• The elements used to evaluate performance, including conflict between systems, out-of-sequence operation of systems components, and energy and water usage profiles; 
• An action plan for identifying and correcting operational errors and deficiencies; 
• Training to prevent errors; 
• Planning for repairs needed to maintain performance; and 
• The frequency of analyses in the first year of occupancy (at least quarterly). 

FN: How have improvements in building technology - specifically the wider availability of IoT devices - enhanced the capabilities of facility managers to do monitor-based commissioning effectively? 

Ridolfi: Many systems can connect to smart phones. This keeps facility managers fully engaged with their building without the need for being onsite 24/7. This further amplifies the benefits of a MBCx system. Nearly 50 percent of commercial office buildings are still limited to monthly or quarterly utility data for energy and water. They significantly delayed in responses to unknown building operation, which may not be fully highlighted through a legacy BAS with no IoT connected devices. 

Greg Zimmerman is senior contributor editor for the facility group, which including FacilitiesNet.com and Building Operating Management magazine. He has more than 18 years’ experience writing about facility issues.