Most daylight harvesting schemes fall short of performance goals, says study

Analysis of daylighting control systems in 20 office and public spaces in Minnesota and Wisconsin shows that while the automatic daylight harvesting schemes are helping to reduce lighting energy in the buildings, most are not achieving optimal performance, according to a new study by the Energy Center of Wisconsin (ECW).

According to ECW, the median daylighting control system studied was saving 23% of lighting energy, including impacts on heating and cooling. This translated to 915 kWh saved for every kW of lighting controlled. But the average effectiveness (the energy saved versus energy saved with ideal control) of the controls was only 51%. This meant that almost half of the potential savings from these controls was not captured due to imperfect controls operation. Even worse, four of the 20 spaces studied had zero savings.

The low level of effectiveness, says ECW, is evidence of a lack of controls execution. The findings show that successful implementation of automatic daylighting control requires a significant commissioning effort to reach full energy-savings potential.

Read the full daylighting commissioning report from the Energy Center of Wisconsin.

As part of the report, ECW developed a tip sheet on commissioning and calibration and function testing of lighting controls. Recommendations include assigning a single person of the construction team to be responsible for verifying completion of all steps in the daylighting commissioning process, and proper training of the building owner/operator on the controls equipment and systems. Download the tip sheet (PDF)

(http://www.ecw.org/project.php?workid=1&resultid=494)

Boyd R. Zoccola is Chair and Chief Elected Officer of BOMA International. A BOMA member since 1994, he has served on the Executive, Finance, Investment, and Medical/Healthcare Facilities Committees. An Indiana Real Estate Principal Broker and a board member of the Real Estate Round Table, he is Executive Vice President of Hokanson Companies, Inc., of Indianapolis, and has been involved in the development of $600 million worth of real estate. On a volunteer basis, Zoccola was president of Horizon House and a board member of Girls, Inc. He holds a BA in biology from Indiana University.