How to store food - and save energy

How cold should it be in a refrigerator? How do I know which products can withstand what temperature? And am I wasting energy? Here are the rules you need to know – and some valuable tips for better temperature control.
  • Viktor Bardun




How to store food – and save energy
Photo by Smederevac / Getty Images
If a product is marked with a "use by" date, you know it is perishable. Fruit and vegetables prefer a slightly higher temperature, between 4 and 7 °C.

Temperature control is mostly about ensuring food safety, and we have strict requirements for fridges and freezers in Europe. The main rules are that

  1. perishable foodstuffs must be stored at 4 °C or lower
  2. the cold chain must be uninterrupted
  3. the temperature of freezers should be -18 °C or lower

But even in the good fight against microorganisms, it's foolish to use more energy than necessary. So it's worth looking closely at the product: What is the specified storage method? If you have several products that can withstand temperatures higher than 4 °C, you can store them together in a separate cabinet. It's a waste of energy to keep them at a lower temperature than necessary.

How cold is too cold for your refrigeration units?

Stacking items too high in the freezer often leads to excessive energy consumption. Never pack items over the packing line, as you risk restricting the air supply. The freezer then has to compensate for this and uses more power.

Of course, when it comes to your freezer, it's not like -36 °C is twice as good as -18 °C. Anything below 22 °C is, in practice, the equivalent of throwing energy right out of the window. So it's best to keep the temperature in the freezer within this 4-degree range. The temperature will fluctuate, but if you have IWMAC monitoring, you'll get reports with temperature logs every 24 hours. That way, you can quickly check if products are in danger – or if there is energy to be saved.

Cool facts about temperatures

At Kiona, we often visit new customers at supermarkets to supply training. Once accurate temperature monitoring is in place, many have a real lightbulb moment. Here are the most common experiences, summarised in three practical temperature tips.

1. Close the door to the freezer or refrigerated room when restocking

Heat exchange happens faster than you think. Ensure that the refrigerated/freezer room door does not leak, and never leave it open while restocking items. Otherwise, warm air and moisture can sneak in, and ice forms.

2. Don't let the ventilation work against you

Fridges and freezers are seriously affected by the temperature and air humidity elsewhere in the store. When summer finally arrives, this is especially important to look at and address. If it's 20 °C in the store with 40% humidity – as it is in winter – you'll have around a 55% load on the refrigerated counter and freezer. However, if it is 20 °C with 60% humidity, the load will quickly become 75%. And that's something you need to keep in mind.

I have even seen ventilation systems blowing 27 °C warm and humid summer air into the store. Then we're talking a load of over 100 percent. It's a complete waste when two systems are fighting against each other.

Viktor Bardun, Sales Coordinator, Kiona

3. Don't leave the door of the store open

And last but by no means least: We understand that it can be tempting to leave the store's door open in the summer. Many people do, but it's not good for your refrigeration and freezer system. Better to have the store a little cold and close the door. This gives your food a safer environment and reduces your fridge's freeze burden – and your electricity bill.

Make sure your produce always stays fresh