Building retrofits boost energy efficiency and sustainability

Whether it’s driven by sustainability goals, regulatory requirements or a simple need to reduce energy costs, a growing number of property owners are looking to improve the energy performance of their buildings.

While financing those projects is a perennial challenge, new approaches to building management and renovation, emerging technologies within the MEP world, and shifting thought leadership about sustainability are providing avenues to meet clients’ needs.

Retro-commissioning

Inefficient and even erratic operations within buildings that were designed to be highly efficient is not a new thing.

When Bala Consulting Engineers assess building performance at a client’s property, they regularly uncover “hand-o-matic” issues with MEP systems, said John Robinson, Director of Commissioning. “A tenant in the building may have complained about the temperature so the facilities staff did an override and that piece of equipment has been running at higher speed for however long, wasting money instead of going back to its automated programming.”

Retro-commissioning can ferret out and correct those misalignments and accomplish much more. It can identify delayed or neglected maintenance that is impacting the performance or efficiency of building systems and shortening the lifespan of equipment. And it can go beyond resetting a building to original performance and efficiency levels to improve on those levels.

“We now have the tools, the data and the analytics to accomplish greater efficiency,” said Michael Westerlund of Johnson Controls Inc. “Analytics are creating feedback loops of data that are timely and continuous so you can be constantly monitoring and adjusting building operations.”

In newer building systems, those analytics can finetune operating sequences to match real-time occupancy levels, flexible work schedules and changing uses. The analytics can also flag minor equipment issues that can diminish efficiency and shorten equipment lifespan.

“This not only helps owners maintain energy and system efficiency, it also helps service technicians very quickly identify root causes of problems. This generates significant operational savings,” Westerlund said.

The addition of AI to the analytics systems, he added, can further increase the benefits. For example, AI-enabled systems can identify and even anticipate maintenance issues and propose scenarios for addressing them. Through continuous learning and adaptation, the AI model can refine its predictions based on real-world outcomes, continuously improving its accuracy and effectiveness over time. This continuous learning loop ensures that the predictive maintenance system remains highly effective even as building conditions and equipment evolve.

More clients are opting to contract companies to do ongoing or continuous commissioning of buildings.

At the same time, retro- and continuous commissioning, with the power of data and analytics, is teac

“Sometimes, the complexity of control systems can become a problem,” said James Gardler, Director of MEP Operations at Bala Consulting Engineers.

Facilities staff may have insufficient knowledge to make needed and effective changes to the systems, and to reverse overrides.

Consequently, engineering companies are both improving their systems for initial and ongoing training of facilities staff and adding functions to systems to make them more operator-friendly, such as a built-in process to automatically restore normal operations.

Portfolio-wide retrofits

To achieve major energy efficiency improvements or sustainability goals, especially in older buildings, some owners are opting for deep energy retrofits and not just on a one-off basis, said Julia Gisewite, Chief Sustainability Officer at Turner Construction Company.

“We have clients who will ask us to look at their entire portfolio of buildings and develop a plan to decarbonize the portfolio rather than looking at one building at a time,” Gisewite said. “That enables everyone to think strategically about procurement, to look across their entire pro forma and how they are spending money, identify priorities, and create a phased plan for decarbonization over multiple years.”

That approach enables companies to achieve some economies of scale in equipment and service purchases. It also helps clients to time retrofits to meet requirements of new Building Energy Performance Standards (BEPS) which are being adopted in many regions.

At James Posey Associates, engineers have recently worked on multi-building energy performance and retrofit analyses on properties ranging from laboratory and manufacturing spaces for life sciences companies to academic campuses.

Those broad studies have helped clients get a sharper understanding of what will be required to meet their own energy efficiency/sustainability goals or upcoming government regulations, said Sean Soboloski, an engineer specializing in energy and sustainability at James Posey.

Analysis of a selection of buildings on one university campus, for example, provided insights on what the client would need to do in the short term and longer term to meet BEPS requirements.

“One of the biggest takeaways from the study is that sub-metering is going to be critically important in dealing with BEPS,” Soboloski said.

Certain uses, such as commercial kitchens, are exempt from BEPS restrictions on greenhouse gas emissions on site. Consequently, installing sub-metering in an academic building that also includes a food hall would be key to lowering and meeting that building’s BEPS requirements, he said.

Other recommended short-term actions, he said, included retro-commissioning campus buildings to better monitor occupancy and adjust HVAC operations accordingly and completing a building envelope commissioning to lower energy loss.

However, Soboloski noted that longer term improvements for that university, like many institutional clients, include replacing HVAC, electrical and back-up power systems, many of which have already exceeded their expected lifespan.

New concepts in efficiency

For clients who are wrestling with the high cost of improving their energy systems, thought leaders in sustainable building are offering some new options.

One is a “partial electrification” solution.

“Partial electrification could be huge and I hope it gets more attention in the engineering practice,” said Colin Schless, Director of Client Decarbonization Strategy at Turner Construction Company.

Schless points to a study by the Berkely Center for the Built Environment which concluded that building MEP systems run at 20 percent of capacity for 80 to 90 percent of the year and only run at higher capacities during high-demand periods.

“So, if you electrify 20 percent of that plant, that’s going to cover 80 to 90 percent of emissions,” Schless said.

Partial electrification would deliver major decarbonization gains while dramatically cutting the cost of installing new equipment, Schless said. Also, “by just electrifying 20 percent, you’re not likely to impact your electrical load so you don’t need to do electrical service upgrades to the building, which are costly.”

Another emerging option is high-lift heat pumps.

The obstacle to installing heat pumps in an existing building is “most buildings have a boiler that uses pretty hot water – 170 to 180 degrees,” Schless said.

Heat pumps typically deliver 120-degree water. Accommodating that temperature water in an existing building “would mean ripping out radiators, ripping coils out of your air handling units and making some architectural improvements. It’s a really intensive project,” he said.

The high-lift heat pump leverages technology typically used in the food and beverage and oil and gas industries to create a solution for buildings. The two-stage heat pump brings water to 120 degrees in the first stage and raises it to 180 to 200 degrees in the second stage, making it compatible with equipment installed in many buildings.