Final results of a four-year landmark building lighting study by the National Association of Lighting Management Companies (NALMCO) provides a roadmap for achieving potential savings of 10 percent of the lighting costs or more––or from $2.7 billion to $3.6 billion in savings annually––for many building owners everywhere in the United States over the life of their buildings by simply cleaning fixtures on a regular maintenance schedule.

Known as the Luminaire Dirt Depreciation (LDD) study, the federally funded project involved taking scientific measurements of available light over four years throughout the test group sampling to determine the benefits––in terms of both improved lighting and reduced costs––of periodic cleaning of the lighting fixtures themselves, with a goal of installing fewer fixtures in the first place.

U.S. Environmental Protection Agency figures show the electricity to run commercial and industrial buildings costs $90 billion per year, with lighting accounting for 30 to 40 percent of electricity use in commercial buildings. “That translates to $27 to $36 billion spent on lighting annually,” NALMCO said. “Based on the study prediction of 10 percent savings using maintenance procedures, EPA calculations indicate an annual savings of 10 percent of total commercial and industrial lighting costs nationwide, or $2.7 to $3.6 billion each year.”

The study targeted office buildings, schools, health facilities, and retail stores. NALMCO says preliminary results were released two years ago as the study was nearing completion, but that the final results “were significantly more definitive.”