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Within the food and drink industry, refrigeration is vital throughout different steps of the manufacturing process to ensure that food is kept fresh and the highest standards are achieved. But how does refrigeration work? Fridges are a common everyday appliance, but do you actually know how they work?

Without refrigeration, food doesn’t last as long and doesn’t stay fresh. Plus, if food isn’t stored correctly, you run the risk of cross-contamination and bacteria spreading throughout your products. With that comes a whole world of problems – hefty fines, ill consumers, poor reputation and potential closure. Doesn’t sound great, does it? 

This blog will outline exactly how refrigeration works, the importance of refrigeration within the food and drink industry, the different methods of refrigeration and much more. It’s your all-in-one guide for food refrigeration – you needn’t look anywhere else.

We’ll cover: 

  • The Working Principle of Refrigeration
  • The Different Components of a Refrigerator
  • How Does Refrigeration Work?
  • The Different Methods of Refrigeration in the Food and Drink Industry

The Working Principle of Refrigeration

Refrigerators are an everyday appliance – there’s not a day that goes by where people don’t use them. Whether it’s grabbing the milk for your morning cereal, using a refrigerator at work for your food business or even looking in the fridge in the evening through boredom – yes, we’ve all been there – we all rely on them day in, day out. But how does refrigeration work? 

On a very basic level, there are three steps in the process of how refrigeration works. These are: 

  • To keep items inside the fridge nice and cool, a cold refrigerant is passed around.
  • This refrigerant absorbs all heat from the products and food items inside. 
  • The refrigerant then takes this heat and transfers it into the cooler surroundings. 

And that’s basically how items stay cold in your fridge – our explanation doesn’t end there, of course. We’re going to delve further into the science and the different components that make chilling food products this easy. 

What did we do before refrigerators were invented? Having to store food underground or use running water must’ve been so inconvenient – not to mention a health risk too. Since the invention of the refrigerator, keeping things cool is as simple as opening and closing a door! Refrigerators help businesses stay hygienic, efficient and operate at a top-level. 

The Different Components of a Refrigerator

Expansion Valve

The expansion valve is the key component that controls the distribution of the refrigerant coolant. It works closely with the evaporator to ensure that items are kept cool and temperature controlled. It’s a small, sensitive component that manages the temperature inside the fridge and ensures that it’s always at that point. 

Without the right distribution of coolant, you could expect different parts of the fridge to be different temperatures. Obviously, this isn’t ideal as you need to ensure that all food is refrigerated at the same temperature to follow food hygiene best practices. Storing food at the wrong temperature could lead to it going off and being unsuitable for consumption a lot quicker. 


The evaporator is the part of your fridge that actually keeps your items cool. It’s made up of metal finned tubes that are designed to maximise heat transfer. That way, your evaporator can absorb the heat from the items in the fridge and start cooling it down immediately. Heat is absorbed and turned into a liquid refrigerant vapour inside the fridge. 

One of the evaporators main functions is keeping the internal temperature low. A fan blows over the evaporator cool at a very low temperature, which is then circulated into the load space of the fridge. Refrigerant is low-pressure, low temperature at this point and returns to the compressor. 


A refrigerator’s compressor sucks in the refrigerant from the evaporator and converts it into a hot, high-pressure gas. The compressor is the heart of the system – without it, the refrigeration cycle would only run once. This component pumps out the gas to start the refrigeration cycle all over again and keep items cool constantly – not just for a small period of time. 

A compressor will work closely with the condenser. Once it’s pumped out high-pressure hot gas, it forces the condenser to get to work and start the refrigeration process once again. You might be thinking, “what place does hot gas have in a refrigerator?” – well there you have it!

How Does Refrigeration Work?

To start with, the refrigerant (or coolant as it’s popularly known) is in a liquid form. From here, it passes through the expansion valve and due to a sudden drop in temperature, it’s transformed into a cool gas. 

As the cool gas is now distributed throughout the refrigerator, it absorbs heat from the products that are placed directly inside the unit. The coolant, which is now in gas-form, flows inside the compressor. Inside the compressor, the gas is turned into a high-pressure, hot gas – due to all the molecules being pressed together tightly. 

After leaving the compressor, the hot gas is transported to the condenser at the back of the refrigerator. The coils that are specially designed in the condenser react with the gas and change its temperature while offloading the heat elsewhere. These pipes feel hot to touch.

Within the condenser, now that the heat is gone from the gas, it’s cool enough to turn it back to a liquid. Once back in liquid form, the refrigerant will travel back to the expansion valve and start the process all over again. Due to the pressure dropping when being transported, the coolant will arrive as a cool gas. 

And that’s how your fridge and the items inside stay cool and best stored!

The Different Methods of Refrigeration in the Food and Drink Industry

Industrial Refrigerators

If you’re preparing, serving or selling food dishes and products, you’re going to need industrial refrigerators or portable refrigerators as standard. You need to ensure that your preparation is spot on. If you don’t store your food properly, you run the risk of threatening somebody else’s overall health and wellbeing. Keeping food at the correct temperature ensures that your products are always fresh and in the best condition possible. 

For food and drink establishments, your hygiene record is everything. If you achieve the top score possible, it shows that you take it seriously and care about what you do. Plus, it’s a lot more attractive for customers and gives them the peace of mind that you’re taking all the necessary steps to keep them safe. 

Refrigerated Vehicles

Like any other industry, the food and drink industry relies heavily on suppliers. But how can you transport food safely so that it arrives in perfect condition? Well, refrigerated vehicles are the answer! From fresh meat to fruit and vegetables, refrigerated vehicles are necessary to keep food products in their prime condition. 

Can you imagine the condition of meat having been sat in a van all day that’s not refrigerated? We wouldn’t want you to! That’s certainly not a safe way to handle food and definitely won’t be fit for human consumption. Luckily, refrigerated vehicles come in all different shapes and sizes – from small vans to lorries. Therefore, there’s no excuse for any supplier to be using unrefrigerated vans – it’s not safe practice – it’s as simple as that. 

Refrigerated vehicles operate very similarly to normal refrigerators. However, their main purpose isn’t to cool items down, it’s to ensure that food products arrive at their designated destination in the condition that they were originally sent in – temperature recording can help to maintain this. Plus, they’re not powered by a mains source like typical refrigerators are – they can be powered on a direct drive or additional compressor basis. 

Find Out More About Refrigerated Vehicles

As we’ve just mentioned, refrigerated vehicles are necessary for the safe transportation of your food products. With that in mind, it’s important that your business chooses the right one to meet your individual needs and requirements. From size, load weight and power source, there are many factors that need to be considered when choosing the right refrigerated van for your company. 

It’s a big decision to make – so you shouldn’t rush into it at all! You need to make sure that you’re as educated as possible, so that you can choose the right vehicle for your business to run efficiently and smoothly. With that in mind, we’ve prepared a free guide that shows the fleet of vans that we stock at CoolKit. 

From the van specifications to how they can benefit your business logistics, it’s all included in the guide for you to benefit from! However, it’s not quite ready yet… it just needs the finishing touches. So, with that in mind, please feel free to get in touch and see how we can help your business find the perfect solution.