All cold rooms have one thing in common: the energy used by refrigeration and cooling technology is the largest cost in your operation. The trend of energy costs in recent years shows that prices are increasing year after year. There isn’t much opportunity for improvement in the cost of electricity given the existing energy supply situation in Europe.
Figure 1. Development of energy prices in Germany.
This leads to operators of stores with large refrigeration requirements currently looking for ways to reduce their energy costs. Approximately 70% of the operating costs of a frozen food store are due to refrigeration. In addition to high energy costs, increasing environmental impacts are also the consequence of inefficiently operated refrigeration. We have outlined several measures that can assist operators in minimizing their costs in to avoid the consequences mentioned above.
LED lighting with motion detector and door monitoring
Temperature-controlled logistics centres, food producers and distributors operate without a night’s rest. Large cold room facilities that operate 24/7 notice the extent of their facility’s lighting costs. Outdated light sources (e.g. lightbulbs) can dramatically increase the cooling requirements of cold rooms by emitting a lot of heat. On the contrary, modern LED lighting systems, which are also available with integrated motion detectors, allow savings of up to 80%.
Figure 2: Door monitoring with door detector and signal light.
Motion detectors are also a useful addition to optimize doors and gates. Open doors can be considered as gaps in the insulation of a cold storage facility. Thermal insulation is one of the most critical features of a cold storage facility, as cooling efficiency is highly dependent on how well or poorly the walls and roofs are insulated. Automating doors minimizes the time when warm, moist air can enter the cold room from the outside. This also reduces the energy the refrigeration systems use to keep the temperature of the cold room constant.
Setting the temperature correctly and monitoring
Setting the temperature correctly is also critical in keeping energy costs down. Different products have different temperature requirements. For example, egg products need to be stored at a maximum of +4°C frozen foods need to be stored at no more than -18°C traded. The temperature should only be set as low as is necessary to reduce the power required by the refrigeration equipment. For example, a cold room temperature of -24°C instead of the required -18°C already results in 30% more energy consumption. Adjustments in cold room temperature should be made whenever the products in the warehouse change. As a supplemental measure, temperature monitoring is also useful, since fluctuations in temperature should be avoided at all costs. Unnecessary temperature fluctuations endanger products and overload compressors. To avoid sudden temperature changes, it is recommended to reduce door movements, cool the products before storage and optimize defrosting processes.
Optimized control of defrosting periods
Refrigeration systems and cooling processes operate below freezing point and tend to build up ice – just like in our refrigerator at home. To keep the evaporator in cold rooms free of frost, defrosting processes are often initiated on a timer. Unfortunately, each defrost brings heat into a space that needs to be cooled. To avoid this, defrosting periods should be optimized.
Figure 3: Improving temperature fluctuations with Coldsense solution.
Our intelligent defrosting system allows us to find the optimal defrosting strategy for our partners. Using artificial intelligence, we combine our self-developed ice sensors with environmental conditions, logistic operations and applicable energy prices to accurately determine the best timing for evaporator defrosting. The energy consumption of the refrigeration system is thus reduced by up to 20% with the help of our solution.
Creating a general energy efficiency concept with a Coldsense system solution as an intelligent core part
Rising energy costs are currently urging many companies particularly to make their systems more efficient. Companies should have a holistic approach to energy issues instead of implementing isolated measures that do not exploit hidden savings potential. Intelligent defrosting can be combined with various energy optimization measures:
- If there is a PV system with a surplus available, the defrosting can be set to use only green energy (from the PV) for this.
- If the surplus from the PV system is high, the cold rooms can be used as energy storage and the defrosting can be adjusted accordingly.
- If there are energy storage possibilities, then the intelligent defrosting system takes into account the charge state of the storage to use the energy optimally.
Figure 4: Percentage of defrosting with green electricity in October at FDBS.
The energy management concept also includes the control of energy flows, considering different generators, storages, energy sources and consumers. Our system solution is also able to analyze and optimize these flows.
A summary of the different measures to save energy in cold rooms can be found in the following table:
| Measure | Potential energy savings |
| LED lighting with motion detector | Up to 80%of energy costs for lighting |
| Door monitoring* | Helps to reduce temperature fluctuations |
| Properly setting the temperature | Cooling to -24°C (if only -18°C is necessary) results in 30% more energy consumption. |
| Temperature monitoring* | Helps to detect and reduce temperature fluctuations |
| Optimized defrosting* | Up to 80% reduction in defrosting time and 20% lower energy costs by improving heat transfer. Contributes to the reduction of temperature fluctuations. |
| Reduction of temperature fluctuations* | Up to 12% of the energy costs. |
| Measures marked with * are included in the Coldsense system solution for cold rooms. | |
Contact us if you want to learn more about savings in refrigeration.
