Return on Recommissioning

The recommissioning study results in recommendations that can range from no-cost fixes to solutions requiring engineering or capital expenditures. A common no-cost adjustment is to set the controls to dial down or turn off the HVAC system at night, when the building is unoccupied, instead of running it 24 hours a day.

Gene Sieve, a project manager for mechanical and electrical engineering firm Dunham Associates in Minneapolis, offers a hypothetical example. Suppose the client has a 50,000-square-foot building (toward the low end of sizes for which recommissioning is cost effective) that is 50 years old. The building’s office configurations and the way it is used have changed significantly over time. Now it has high energy costs and wild temperature swings in certain areas.

“First,” Sieve says, “we would evaluate the documentation of the HVAC system. What was the original intent? Then we’d look at how the building is responding to inputs like thermostats telling [machinery] to go off and on.” He also would check the “performance characteristics” of the boilers or chillers. He might “reconcile the layout with how the building is now being used,” and recommend better locations for thermostats. And he might suggest that the system be set to shut off at 6:00 p.m. instead of at midnight.

The energy savings achieved, the cost of gaining them, and the payback period depend on how far out of whack the system is and the nature of the fixes required. “We prioritize options with paybacks of, say, six months to two years,” Sieve says. Most building owners balk at recommendations with payback periods of more than seven or eight years.

That helps to explain why recommissioning is far more common in the public sector than in private commercial buildings, suggests Dale Holland, Dunham Associates’ chief technical officer. “The incentives relate to how long the owner will own the building,” Holland says. “An office retail developer might expect to own a building for five years. For a school district, it might be 50 years.”

Public schools are a prime market for recommissioning projects, experts say, partly because they are subject to stringent air-quality regulations. Elsewhere in the local public sector, sources say that Hennepin County has recommissioned a number of buildings, as has the University of Minnesota.

Experts agree that commercial building owners have shown increasing interest in recommissioning for the past five years or so. They cite reasons including the rising price of natural gas and greater concern about energy conservation and environmental issues. Hewett says that Xcel’s rebate program  has sparked interest in more ways than one. It isn’t just the money, but the endorsement of the process that matters, she says. Recommissioning can sound suspect to building owners “because you’re buying consulting expertise, not a new boiler. So it’s helpful for a trusted entity like Xcel to tell people, ‘Yes, you can save a lot of energy by doing this.’”

Still, private owners usually must be in greater pain than public ones to pay for a recommissioning project. Two years ago, Cook performed a study for the Bremer Bank building in South St. Paul. The systems were so far out of whack that most of the offices had to use electric heaters in winter “and they were running the boilers and refrigeration units at the same time.” After the bank implemented the study’s recommendations, Cook says, natural gas use dropped by an eye-popping 90 percent in the summer and more than 30 percent in the winter.