Reducing costs for cooling, heat and indoor air

Customers are supposed to feel comfortable in a store. Retail does a lot to make this happen, but some things are not noticed immediately. Heating is expensive, but cooling is even more expensive. Costs can also be reduced for normal indoor air. We take a look at cooling shelves and freezers on the one hand, while we also take a glance into the warm world of bakeries.

In a 2011 survey, the EHI Retail Institute found out that non-food retailing spends about 32 Euros per square meter of sales area annually on energy. According to the study, at 57 percent lighting is the largest energy hog in non-food retailing. More than 55 Euros per square meter of sales area annually are spent on energy in food retail, of which cooling at a share of 45 percent accounts for the largest electricity consumption. According to the EHI, retail has invested a lot in measures to optimize energy use over the past years. Recently, the readiness for this only increased clearly in the lighting sector.

The EHI gives the “Energy Management Award” for particularly innovative or successful concepts in energy conservation. The award goes to commercial enterprises, which implemented current, successful concepts in energy conservation in their shops. The next awards ceremony takes place on October 16, 2012 within the context of the Energy Management in Retailing Conference.

Saving energy in cooling systems

It is not so easy to determine individual electricity hogs at the supermarket. Only few markets collect individual consumption data for each cooling device. Manufacturers can help with average values for refrigeration systems, but you can also assess your own values by measuring. More and more supermarkets utilize the waste heat of cooling devices for hot water heating or for preheating incoming air. These measures are expensive, but they can save more than a third of heat energy.

A feast for the eyes: service counters often need cooling. Modern cooling units save energy.

”The cooling chain is to become more eco-friendly“, EuroShop.de reported two years ago. Retail can cut costs by protecting the environment and do a lot for its public image. CO2 made news as an alternative coolant. Aldi put the first cooling truck with this new technology on the road; chain stores tested new freezers and cooling shelves. Apparently, expectations were greater than early results. Individual manufacturers of refrigeration units pursue different methods. While some promote CO2 cooling, others look for alternatives. Arneg, a manufacturer from northern Italy relies on brine, salt water, as a coolant solution. New coolants enter the units, requiring less cold than was necessary in the past.

Retail needs to decide between freestanding solutions and cooling units that are connected to a cooling circuit. EuroShop exhibitor AHT promotes plug-in based solutions. They are considerably more affordable to purchase, planning effort for complex installations is not necessary and you can gradually convert to new, energy-saving technology. That said, waste heat remains unutilized in the market and warms up the sales floor, which in turn may require costly air conditioning. In addition, the units have to regularly be cleared out manually and defrosted.

New cooling units or upgrading existing inventory

Modern cooling units need considerably less electricity; however, previous products are used for up to 15 years – due to extensive wear and tear, it is a few years less for discounters. Yet it is quite easy to retrofit with nightshades, glass doors for cooling shelves and glass covers for open freezers. Most cooling shelves in Germany are glazed at this point, says Peter Ebbing from special-purpose glass manufacturer REMIS in a EuroShop interview. Due to heavy customer traffic, discounters still have reservations; frequent door opening reduces energy savings and customers could hinder each other.

Energy saving with the cooling shelf: customers are getting used to the glass doors.

Light emitting diodes are becoming more and more important for refrigeration units, but they are still quite expensive. LEDs give off less heat than previous light fixtures. What’s more, manufacturers try to save energy for cooling through improvements in airflow. The problem is the flow profiles developed by engineers only work if retail stocks shelves, counters and freezers as intended. In everyday life however, stacking heights are oftentimes exceeded and vent openings or intake ports obstructed with merchandise. Experts estimate that you could save around 15 percent in energy just by improving the restocking process, servicing and maintenance of cooling units.

Heat and cooling energy for bakers

Hot and cold are close neighbors in bakeries. Many costs can be reduced with energetic optimization. In our second EuroShop Interview on this focal topic, Eike Zuckschwerdt explains what is important. He works for MIWE, a traditional manufacturer of ovens for bakeries, which has long since also equipped the food trade and gas station convenience stores with baking stations. Retail gives traditional bakers a run for their money with its in-store made breads and rolls.

Baking is often still a craft for small companies. Personnel expenditures are high and right now, costs for flour and other raw materials are strongly increasing. However, bakers can tackle their energy costs. MIWE and other suppliers are not just offering more efficient ovens, but also energy consulting. Eike Zuckschwerdt says, combined heat and power generation is definitely interesting for bakers. The waste heat that is generated by the bakery’s refrigeration system can be used to cool fermenting dough or the indoor air. This waste heat comes from the refrigerated display cases in the store and the refrigerators that house raw materials and supplies.

Ventilation and air conditioning help sales

Customers linger longer and buy more if they feel comfortable in the store. Modern ventilation and air conditioning helps. The equipment needs to be correctly dimensioned. Engineers have to consider the so-called ”interior burdens”, meaning the waste heat from lighting, the impact of refrigeration units, the often very long opening hours and the sometimes strongly fluctuating number of visitors. Operating costs of ventilation and air conditioning equipment exceeds acquisition costs after just a few short years. That is why additional investments in more efficient measures usually amortize in less than three years. One important component for this is waste heat recovery. Everyone should conserve energy – supermarkets, discounters, non-food retailing and bakeries.

René Schellbach, EuroShop.de

01.10.2012

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