A recent study from Rensselaer’s Lighting Research Center (LRC) found that shoppers overwhelmingly prefer light-emitting diode (LED) to fluorescent light inside supermarket freezer cases. LED lighting – known for its bright, even quality — increased frozen merchandise appeal for consumers when placed in grocer’s freezers, according to the researchers.

Following a study in 2002, LRC researchers concluded that white LEDs would make ideal light sources for freezer and refrigerator displays. To further validate their findings, the scientists conducted a two-year field study — sponsored by the New York State Energy Research and Development Authority (NYSERDA) — to evaluate a prototype freezer case outfitted with one-watt, high-power white LEDs installed at a local supermarket.

Over the course of the study, the LRC investigated shoppers’ preferences for an LED-lighted freezer case compared to a matching freezer lit with conventional fluorescent lighting. Approximately 300 shoppers were asked their opinions about the lighting of the two test freezers, and more than 86 percent of consumers selected the LED-lit freezer as the one they liked the most, saying that the products were more appealing, and the lighting was more even and comfortable to look at.

“Even though the average illuminance level of the fluorescent-lighted freezer was slightly higher, the uneven light distribution led to areas at the center of each glass door that had roughly half of the average LED light level,” said Nadarajah Narendran, director of research at the LRC. “This likely led to the perception that the LED case was brighter.”

LEDs can not only save energy, but they also last much longer than fluorescent lamps in freezer environments, providing a much lower lifecycle cost for owners, according to Narendran.

Several manufacturers now offer commercial LED systems for lighting freezers and refrigerated display cases.

Published March 19, 2007