Retrocommissioning takes a relatively modest upfront investment. According to a study by Lawrence Berkeley National Laboratory (LBNL), the average cost for retrocommissioning is $.30 per square foot. But the return on that investment comes quickly: The median payback time is a little more than a year. That’s not surprising considering that the median energy savings is 16 percent. And those savings last, says LBNL: “Energy savings tend to persist well over at least a 3-to-5 year timeframe.” Savings may last longer than that, but the study didn’t have data for longer periods.
“Energy savings is a substantial and important byproduct of retrocommissioning,” Moser says. “But it’s not the only benefit.” Indoor environmental quality is another big gainer. With controls functioning better, for example, occupants may have the benefit of more stable temperatures, which could cut hot and cold complaints. And the system is more likely to bring in the right amount of outside air.
Longer equipment life is another significant benefit, says Moser. That’s especially true of valves and dampers controlled by an actuator, which suffer excess wear and tear if they are being opened and closed more often than necessary.
Increasingly, another factor is likely to point to retrocommissioning: greenhouse gas emissions reduction. LBNL says that commissioning of all sorts, including retrocommissioning, can provide large reductions in carbon emissions. Commissioning, it says, is “arguably the single-most cost-effective strategy” for cutting greenhouse-gas emissions from buildings.
A final reason to consider retrocommissioning may come from the local utility. In some states – notably California — utility incentives have been available to help cover the cost of commissioning. Other states that have offered utility incentives include Colorado, Minnesota, New York and Texas, says Moser. For utilities the benefit is very simple: By reducing the amount of energy used by a facility, retrocommissioning offers a very cost-effective way to cut the demand on the utility infrastructure.
Although utility incentive programs may make it easier to affordretrocommissioning, those programs often have one drawback, says Moser:a schedule that is too aggressive to get the full benefit fromretrocommissioning. That’s especially true for large, complexfacilities.
“It’s tough to jump in and then jump out two months later” to meet a utility program timeline, says Moser.
But utility programs are a great way to try out retrocommissioning. Andfacility executives who are happy with the results ofretrocommmissioning may choose to continue the effort outside of theutility program. He says that retrocommissioning of a 200,000 to300,000 square foot office building might take 9 months — perhaps ayear if you want to see how the building performs in all four seasons.In a large complex, retrocommissioning may take 18 months, Moser says,though the retrocommissioning agent would not be working full time forthat entire period.
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