KANSAS CITY, Missouri, January 20, 2009 (ENS) – Grocery stores typically spend up to 50 percent of their total energy costs on refrigeration, but they may be able to save energy and money by replacing open display coolers with cases that enclose refrigerated air behind glass doors.
But would customers be as quick to open doors, reach inside and choose products in enclosed cases as they are to select products from open cases?
University of Missouri, Kansas City mechanical engineering professors Brian Fricke and Bryan Becker are trying to answer that question with a detailed study of the amount of energy used by the two different types of supermarket display cases.
Fricke and Becker say many supermarkets are reluctant to use glass door display cases since a common perception is that doors reduce shopper impulse buying. As a result, these cases have had limited success in penetrating the market dominated by open vertical cases.
“It’s important that store owners realize that being sustainable doesn’t necessarily have to hurt profitability,” said Becker. “Thus, the goal of our study will be to prove whether or not door cases in fact have a negative impact on product sales vs. open cases.”
Glass door coolers could be more energy efficient than open coolers. (Photo by HCMN Marketing)
Two Michigan grocery stores, both part of the same national chain, will participate in the study. Both grocery stores will be installing two new refrigerated cases – one open and one enclosed with glass doors.
During the two months of the study, the energy use of each display case will be monitored with HOBO® Energy Logger Pro systems from Onset, a supplier of energy monitoring equipment based in Massachusetts.
The company manufactures data logger and weather station products that are used to measure temperature, humidity, light intensity, voltage, and other indicators used in research, commercial, industrial, and renewable energy applications.
“We’ll be using the Onset monitoring gear to measure air temperatures, discharge temperatures, air return temperatures, as well as electrical consumption of the lights, fans, and anti-sweat heaters on the cases,” explained Fricke.
“Measurements will be taken every minute or so, and we’ll offload the data from both systems on a weekly basis to analyze the energy consumption of both cases,” he said.
Product sales for each display case, as well as total store product sales, also will be tracked with the aid of stock keeping units during the course of the study.
For each day, a variety of data will be obtained from the electronic point-of-sales system at each store, including the barcode of the product, a description of the product, and the quantity and prices of products sold.
The research results will allow supermarket designers to make informed decisions as to which type of display cases to install.
Electric utilities can use this information as a basis for developing new incentive programs to accelerate adoption of more sustainable supermarket designs.
Fricke says the recent adoption of sustainable practices by the world’s largest retailer is having a ripple effect on other retail chains.
“Walmart has taken real sustainable initiative with having doors on refrigerators, solar panels on the roof, and other forward-thinking programs,” he said. “Because of that, other chains are interested in following along in that direction.”
The research is being conducted for the American Society of Heating, Refrigerating and Air-Conditioning Engineers and the Air Conditioning and Refrigeration Technology Institute.


