Case study: Energy saving through refrigerated cabinets

A refrigerated shelf running 24/7 is not a minor consumer. Therefore, this case study on energy saving with refrigeration units does not focus on a single energy-saving promise, but on the real-world daily operations of a medium-sized catering business. The crucial question is: What savings can be achieved when outdated, open refrigerated units are replaced with need-based and more energy-efficient technology?

The result in advance: The greatest effects are rarely achieved solely through a better nameplate. The decisive factors are the correct design, clean installation, appropriate temperatures, and an operating concept that does not place unnecessary strain on the cold chain.

Initial situation: Long operating times, unnecessary heat in the sales area

The study examined a restaurant with daily business, takeaway sales, and a small self-service area. Chilled drinks, desserts, pre-packaged salads, and prepared ingredients were stored in several units. The existing equipment included an open impulse shelf for drinks, an older refrigerated counter in the preparation area, and a beverage cooler behind the counter.

The units were generally functional. Nevertheless, typical weaknesses emerged: The open shelf was located near the entrance and was exposed to drafts and direct sunlight. The refrigerated counter was opened frequently, even though parts of the "mise en place" could have been stored in smaller, separate cooling areas. On the beverage cooler, the door seals were visibly worn. In addition, the waste heat from the units increased the room temperature, which in turn placed a burden on air conditioning and the comfort of guests and staff during the summer.

For the evaluation, a consumption of around 12,800 kWh per year was assumed for these three refrigeration units. At a price of 0.34 euros per kWh, this corresponded to annual electricity costs of about 4,350 euros. The consumption was not extraordinarily high – but it could be significantly reduced with manageable measures.

The investment: Not every refrigeration unit saves energy in the same way

The solution was not to replace all units across the board with the largest possible new appliances. First, the actual demand was considered: product range, peak times, frequency of access, location, and required temperature ranges. This resulted in a combination of three measures.

The open beverage shelf was replaced by a closed refrigerated shelf with glass doors and energy-efficient LED lighting. This significantly reduced cold loss. While an open unit is convenient for quick access, especially for impulse items, the constant influx of warm room air places a permanent load on the compressor. Whether doors are sensible, however, depends on the concept: in a very high-traffic self-service area, they can slow down access. At moderate frequencies, the efficiency advantage usually outweighs this.

The old refrigerated counter was replaced with a model featuring a better-insulated body, self-closing doors, and a need-based workspace. The appropriate size was important here. A refrigerated counter that is too large not only costs more to purchase but also cools unused volume every day. A unit that is too small, on the other hand, leads to overcrowding, frequent opening, and overflow storage in other units.

The beverage cooler was exchanged for a modern glass-door refrigerator with optimized airflow. For operation, it was also specified that drinks should be restocked in prepared batches during peak times, instead of opening the door repeatedly for individual bottles.

Case study on energy saving with refrigeration units: The results

After the conversion, the electricity consumption of the three equipment areas was re-evaluated over the course of a year. Seasonal differences, especially higher ambient temperatures in the summer, were taken into account. Consumption was now around 8,450 kWh per year.

This resulted in a saving of about 4,350 kWh. With the continued rate of 0.34 euros per kWh, the annual electricity bill for these refrigeration units was reduced by about 1,480 euros. In percentage terms, this corresponds to approximately 34 percent.

The savings were not distributed evenly. The closed refrigerated shelf provided the largest share. Previously, it had consumed a particularly large amount of energy due to its open front, unfavorable position, and long daily operating hours. In addition to lower consumption, the new refrigerated counter brought more order to the preparation process. Because ingredients were clearly categorized and provided in appropriate quantities, door opening times were shortened.

In addition to the measurable electricity savings, the establishment reported a noticeably lower heat output in the guest area. This is economically relevant, even if it cannot always be exactly attributed to a single device. Less waste heat can reduce the load on adjacent air conditioning and improves comfort in small sales and service zones.

Evaluating cost-effectiveness correctly

Assuming the acquisition and replacement costs for the three new refrigeration units, including minor adjustments, amount to 7,200 euros net. With an annual electricity cost saving of around 1,480 euros, the simple payback period is just under five years. For durable commercial refrigeration technology, this is a plausible value, but it is not the whole calculation.

Because other factors belong in the investment decision: lower risk of failure, better temperature stability, easier-to-clean surfaces, available spare parts, and a more professional product appearance. If an old unit fails unexpectedly, spoiled goods, emergency solutions, and business interruptions can quickly put the supposedly cheap continued use into perspective.

Conversely, a replacement is not always immediately cost-effective. A technically sound refrigeration unit with a new seal, cleaned condenser, and sensible positioning can still be operated efficiently. Especially for units with low operating hours or those in cool storage rooms, an individual assessment is more worthwhile than a blanket replacement plan.

Four levers that determine consumption in everyday life

Even the best refrigeration unit only achieves its planned efficiency under suitable conditions. In daily operation, four points deserve special attention:

• Installation location: Distance from heat sources, direct sun, fryers, ovens, and radiators reduces the load on the compressor. Also, air circulation at the supply and exhaust air openings must not be blocked by cardboard boxes or furniture.
• Temperature setting: Every degree the temperature is set too low increases energy demand. The setting must match the product group and hygiene requirements, not a general sense of security.
• Maintenance: Dust on condensers, damaged seals, and iced-up evaporators permanently cost energy. Regular cleaning and visual inspections belong in the operating plan.
• Usage behavior: Doors should not be left open unnecessarily. A clear order for goods, prepared refill quantities, and short distances reduce access times without additional personnel effort.

What decision-makers should check before buying

For professional refrigeration units, the purchase price is only one metric. For a reliable selection, operators should first define the required temperature range, the usable internal volume, and the daily access frequency. This is followed by design and location: an under-counter refrigerator, refrigerated counter, glass-door refrigerator, or refrigerated shelf each fulfill different requirements.

Also pay attention to insulation, door systems, lighting, automatic defrosting, cleaning access, and the availability of service and spare parts. Especially in kitchens with high utilization, the unit should not only be economical but also resilient and easily serviceable. A cheap unit without the right capacity or without reliable support in the event of a malfunction quickly becomes expensive in commercial everyday life.

For larger projects, an equipment overview including age, performance, operating time, temperature range, and observed problems is recommended. This allows for prioritization: first, replace or optimize the refrigeration units that run for particularly long periods, emit a noticeably large amount of heat, or are already causing recurring malfunctions. ELB Gastro supports commercial businesses with a wide range of products and personal advice on the right cooling technology.

Anyone who wants to save energy should therefore not start with the electricity tariff, but with the actual cooling process: Which goods need to be cooled, when, where, and how accessibly? This answer leads to a cooling concept that reduces costs, improves processes, and functions reliably in daily business.