Commissioning for beginners: This lesser-known aspect of construction is worth learning about, because it can save building owners big bucks
When you’re an executive holding the blueprints to your new factory, and you’re out inspecting your building site in the middle of a North Dakota prairie, you’re probably not thinking about the U.S. Navy.
Maybe you should be. Because the Navy has a practice that – well, let’s put it this way: If two buildings are built side by side, and they’re identical in every respect except that one underwent this Navy-inspired practice, that latter building likely will feature higher morale among employees, fewer frustrations and, for the building’s owners, thousands of dollars in energy savings a year.
The practice is commissioning. No Navy ship gets put into service without it; and as the evidence will show, no large commercial or institutional building should, either.
Commissioning is the process of making sure that all of the systems in a structure or vessel work as designed. The testing and inspecting make a difference: “We feel comfortable telling building owners that commissioning will deliver roughly a 15 percent gain in energy efficiency,” said Bob Linder, performance group director for Karges-Faulconbridge, Inc., a St. Paul-based engineering firm with offices in Fargo, Bismarck and elsewhere.
“As an organization, we went back to look at some of our larger projects, and we tried to calculate the cost of commissioning against the energy savings. We found that the projects we commissioned had a payback, on average, of just 2½ years. And that’s conservative.”
The easiest way to explain commissioning is to draw out the Navy example. After its christening – the ceremony in which a VIP breaks a bottle of champagne on the ship’s bow – a Navy ship undergoes months or even years of shakedown cruises, a period known as “sea trials.”
The name fits: The vessel gets suddenly accelerated, emergency stopped and otherwise tested and tried, with the goal of making sure that all systems are go.
Then and only then is the vessel commissioned, or put into active Navy service.
On land, the testing itself is called commissioning. It’s a lot less vigorous than the Navy version, but the goal is the same: to make sure all systems work as designed.
Before commissioning, many systems don’t. Nothing against the architects, contractors or engineers, but all of them are people; and in any project as complicated as building a school, office or factory, people make mistakes.
During commissioning, “we find valves installed backwards,” said Andy Cooper, director of operations and commissioning agent for Commissioning Solutions, Inc., in Fargo.
“We find thermostats controlling systems in wrong rooms. We find equipment crammed into spaces that make it impossible to change filters. Things like that.”
Some finds are huge. For example, airflow problems in one building had a university preparing to spend money on a major redesign, said Linder of KFI. But when commissioning agents inspected a hard-to-access duct, they found a return-air filter that simply was caked with dirt.
“And that’s what was restricting the airflow,” Linder said.
“So, we saved them maybe a $100,000 redesign just by changing a filter.”
Most discoveries are minor, but even those add up. Here’s one that had cost the Bemidji School District money for years: schedules drift on air handlers.
Schedules what? Look, you may not have recognized the term, but commissioning agents smiled knowingly upon reading it. That’s because they understand two things: first, that air handlers keep air circulating. And second, that the handlers don’t have to keep air circulating when spaces are unoccupied.
But often, they do keep air circulating. In schools, for example, the handlers sometimes pump air all night long, typically because the machines’ timers didn’t get reset after a concert or other evening event.
That’s “schedules drift on air handlers.” And when it’s corrected, it’s money in the building owner’s bank.
“We just got done at the Bemidji High School, and because that building had never been commissioned, we think we found savings for them of between $110,000 and $130,000 a year,” said Jim Stocke, commissioning agent and senior mechanical designer for the Grand Forks, N.D.-based EAPC Architects Engineers.
There are several kinds of commissioning. There’s retro-commissioning, which is what happens when commissioning agents check out a building (such as Bemidji High) that never was commissioned before.
There’s recommissioning, which is a recheck of a commissioned building to inspect for wear and tear.
There’s continuous commissioning, in which the commissioning firm electronically monitors the building’s energy-use over time.
And then there’s the commissioning Wayne Gerszewski’s doing during construction of Grand Forks’ new water treatment plant. It started during the design phase, and it’ll last throughout construction – in other words, for years.
As with many large construction projects these days, commissioning at the water-plant’s site happens just about every day, said Gerszewski, project manager for AE2S, or Advanced Engineering and Environmental Services in Grand Forks.
That’s because it’s a lot easier to catch and correct problems early – say, when a heater’s being installed – rather than waiting until the unit has been walled off and the building’s occupants are starting to shiver, contractors and building owners agree.
Putting a water-treatment plant into operation is a real challenge, Gerszewski said. “There are lots of filling of basins and testing of systems to consider, because you can’t just open a valve and say, ‘OK, we’re ready to treat water.’
“You have to verify that every system operates, that the water quality meets all of the required standards. You have to prove that all of those functions work properly over time.”
And all of that involves commissioning. Of course, so does this:
“We had a case at another plant,” he said.
A pump was testing as sluggish, and the commissioning agent wondered why. “Turns out it was spinning backwards,” Gerszewski said.
“We repositioned three wires, and zip, everything’s working perfectly. That’s what commissioning does: It discovers those little things that aren’t quite right.”