How does a refrigerator work? We explain!

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Updated on 20 Jul 2023
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Just like about most of our household appliances, we don’t think about how a refrigerator actually works. Thoughtlessly, you put your products in the refrigerator, close the door and trust that -until their expiration date has passed- they will remain in the desired condition. But what system is behind it? Contrary to what most people think, a refrigerator performs its function not by cooling, but by dissipating heat. How that works? We’ll explain it to you below.

The compressor as the core of the refrigerator

What a refrigerator actually does is remove heat from the food and dissipate it to the environment. So it extracts heat from your products. For this reason, the back of your refrigerator is also always hot and the advice is to keep enough space between the refrigerator and the wall so that the appliance can get rid of its heat. A refrigerator needs a compressor, condenser, evaporator, refrigerant gas and a valve to perform its cooling function.

At the core is the compressor, which is also called a heat pump. This motor circulates the refrigerant through the tubes you often see on the rear exterior of your refrigerator. However, many of the tubes are also inside the unit itself. The function of the compressor is to compress gas into liquid.

How is temperature drop triggered? An equation

A refrigerator extracts heat from the food you put in it. The unit cleverly uses that heat to vaporize the liquid refrigerant. This causes the temperature to drop. Compare this to water on your skin. If you don’t dry yourself immediately after a shower, the water draws heat from your skin to evaporate. This produces a cold feeling even when the temperature in your bathroom is more than pleasant.

Refrigerant: liquid and gaseous

The first step of the refrigeration process involves compressing the refrigerant gas and letting it condense into a liquid. The compressor circulates this and pressurizes it. The refrigerant gas heats up considerably as a result of this process. After all, pressure increase leads to temperature rise. The resulting heat must be dissipated into the environment to cool the refrigerant to room temperature. The coolant comes into contact with the ambient temperature on the outside of the refrigerator.

If this cools it down sufficiently, it then cools the inside of the refrigerator. The liquid enters a larger-diameter tube through a finer tube. This leads to pressure drop and thus temperature drop. The refrigerant thus returns to the compressor. And once it does, it can be reused again for this same process.

A suitable ambient temperature as a prerequisite for the cooling process

The cooling process described above applies to all electric refrigerators, including the increasingly popular American refrigerator in our country today. Are you looking for a new refrigerator? If so, it’s important that you can provide the right environment for the appliance to do its job properly. The climate class of each refrigerator indicates the ambient temperatures in which it can operate. The classes used here are N, SN, ST, T and SN-ST. There are minimum and maximum temperature values associated with each category.

Is the ambient temperature below the minimum value? Then the refrigerator cannot evaporate its refrigerant properly. Is the ambient temperature above the maximum value? Then the refrigerator cannot properly dissipate its heat. Both situations lead to reduced appliance operation and increased energy consumption.

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