Supermarket display cabinets for frozen foods have to operate at -18 degrees. That keeps the food fresh, germfree and tasty, but also makes shoppers shiver. It’s cold in the aisles of the frozen foods department. That’s unpleasant for customers and bad for business. So Marks & Spencer, one of the largest retailers in Great Britain, uses heaters in the frozen foods departments in its supermarkets and department stores. Every freezer cabinet has a heater that blows warm air onto the customers’ feet, keeping them warm while they shop. Each heater has a heating coil through which warm water is pumped. Two fans blow across the coil, heating air that is then transported to the floor of the supermarket.
First heating upgrade in the frozen food department
The systems had previously used AC fans. To improve its energy use, Marks & Spencer commissioned ebm-papst with a retrofit for the fans in January 2016. The order called for new EC fans to be installed in 138 supermarkets and departments stores throughout Great Britain. The two companies had already worked together in the preceding year on the replacement of fans installed on condensers for refrigeration systems. “But this was our first-ever upgrade for heaters in the frozen foods department,” says Tony Wright, Division Director for the upgrade market at ebm-papst. That meant some tests with service provider AB Group would need to be performed before the retrofit at Marks & Spencer’s test center in Birmingham, where the company tests everything related to refrigeration.
After four weeks of measurements, it was clear that Marks & Spencer could reduce energy consumption by 29 percent with the retrofit. Management gave the go-ahead. The technicians had to reach high to do the job. “We could only get to the heaters on top of the freezer cabinets from platforms,” says Wright. “So we could only work at night when the stores were closed.” AB Group still managed to upgrade 1,300 heaters for the frozen foods departments to the state of the art in only ten weeks. In all, they installed 2,500 new EC fans, network and control cables, mounting brackets, and 1,300 RMEC-d controllers from ebm-papst.
Shopping experience more pleasant than ever thanks to EC fans
The results were much better than expected. Since the retrofit, Marks & Spencer is saving 58 percent on electricity. Since the fans only have to run at 80 percent of their rated output, the company can save twice as much as originally forecast. On top of that, the new fans are also quieter.
“We’ve optimized the air flow,” explains Wright. “Now drafts that are too hot or too strong around the feet are a thing of the past.” The shopping experience is more pleasant than ever now, something Marks & Spencer benefits from as well. “If the customers feel comfortable in the frozen foods department, they’ll spend more time there,” says Wright. “Instead of just rushing through and grabbing what they need, they look around, get new ideas, and maybe take this or that other product with them.” Now pizza, yogurt or frozen peas can also find their way into the shopping cart thanks to warm feet.