Return on Recommissioning

In some states, including Minnesota, utility companies encourage recommissioning with rebate programs that reduce the up-front costs and speed up the payback. Xcel Energy offers a rebate of up to half the cost of a recommissioning study, with a maximum of $15,000. Additional Xcel rebate programs help defray the costs of implementing various changes recommended by the study.

Xcel rebates contributed more than $32,000 ($15,000 for the study, $18,289 for implementation) to a recent recommissioning project by the Center for Energy and Environment for the Minneapolis headquarters of Thrivent Financial for Lutherans. Built in 1981, the 525,000-square-foot, 17-story building was designed to be “energy conscious,” but was, in fact, plagued for years by high costs and problems with temperature control, according to an Xcel case study. Total cost—for the recommissioning study conducted two years ago and the subsequent implementation of its recommendations—amounted to $185,960, minus the rebates. Annual energy savings (for electricity, chilled water, and steam) are estimated at $190,400, which means that the project paid for itself in less than a year.

At Fairview University Medical Center (nine stories, 585,000 square feet), $45,000 in Xcel rebates reduced the total costs of a recommissioning project from $210,000 to $165,000. Annual energy savings of $180,000 mean the project investment was recouped in just 11 months.

Especially when utility-company rebates are factored in, recommissioning is a “process with no negatives” for building owners, declares Edward Cook, president of engineering-consulting firm Edward H. Cook & Associates, PA, of St. Paul. The process almost always results in energy savings, usually significant and sometimes huge, he says. Air quality and temperature control often improve, as well. After recommissioning, Cook says, “the [HVAC] system doesn’t work as hard. When you use less energy to run it,that means reduced emissions from the plants that make electricity, which means you reduce greenhouse gases. So the owner saves money, the environment wins, and the occupants get a more comfortable building.

What is it, Exactly?

Recommissioning specialist Rebecca Ellis is president of Questions & Solutions Engineering, Inc., of Chaska, and a columnist for the national trade journal Engineered Systems. Here is her formal definition of “conditioning,” as applied to a newly constructed building or a major renovation project:

A systematic process of assuring by verification and documentation, from the design phase to a minimum of one year after construction, that all building facility systems perform interactively in accordance with the design documentation and intent, and in accordance with the owner’s operational needs, including preparation of operation personnel.

Formally, “retro-conditioning” means applying the same assurance process to an existing building that was never commissioned to begin with. “Recommissioning” means coming back and doing it to a building that was previously commissioned or retro-commissioned. But in practice, Ellis says, the term recommissioning is often applied regardless of the building’s history.

Recommissioning is not the same thing as an energy audit, Ellis says, though a study might cover some of the same ground—checking the efficiency of a boiler, for instance. Nor is the goal to repair or replace equipment, although that may be recommended in some cases. The key distinction, she says, is that recommissioning focuses on control systems and how the parts of the HVAC system interact: “Whether it’s a computer-controlled system or an older pneumatic system from 30 years ago, how do the parts work together? You ask whether some components are broken, sure, but it’s more about things being out of calibration or inappropriately scheduled.”

Recommissioning always begins with a study, Ellis says. “Why does the owner think the building is not working? How does the owner want the building to function? Then we evaluate why it isn’t functioning the way the owner wants.”

A building can be “not working” for many reasons, she says. The most common one is that its energy bills are too high, but the owner’s problem also might be that the place is stuffy, or drafty, or hot and cold in the wrong  areas, or that the doors don’t close because too much air is coming out of the building. In museums and libraries, humidity control is a major issue. In office buildings, tenants may be complaining about temperature control or air quality.