How Does a Fridge (Refrigerator) Work ?

Last updated: October 20th, 2022

Want to know how does a fridge work? Before we get into the working mechanism of the refrigerators lets know what a refrigerator is !

So what is a refrigerator?

Refrigerator is a device that cools an particular area, typically for storage of food, drinks or vegetables. Electricity, propane, gas or kerosene can be used to power a refrigerator (or refrigerator). Refrigerators lowers the temperature, so refrigerators can even be considered as evaporative coolers. Most refrigerators also have a freezer and are often labeled “fridge / freezers”.

A fridge (colloquially refrigerator) consists of a thermally insulated compartment and a heat pump (mechanical, electrical or chemical) that moves energy from the inside of the refrigerator to its external environment so that the inside of the refrigerator is cooled under the room temperature. For developed countries, refrigeration is an essential food storage technique. The lower temperature decreases the bacteria’s reproduction rate, thereby decreasing the spoilage rate of the stored products.

A refrigerator holds a temperature a few degrees above the water freezing point. The optimal temperature range for perishable food is around 3 to 5 ° C (37 to 41 ° F).There is Another device known as a freezer which maintains a temperature below the freezing point. Icebox has been replaced by the fridges which has been a common household appliance for century & half.

Ice was used as the first cooling systems for food. In the mid-1750s, artificial cooling started and expanded in the early 1800s. The first working vapor-compression cooling system was built in 1834. In 1854 was invented the first practical ice-making machine. Refrigerators were invented for home use in 1913. The first self-contained unit was introduced by Frigidaire in 1923. In the 1920s, Freon’s invention widened the refrigerator market in the 1930s. In 1940, home freezers were introduced as separate compartments (larger than required for ice cubes only). Frozen foods have become commonplace which was considered a luxury item previously!

For homes and in industry and commerce, freezer systems are used. Commercial refrigerator and freezer systems have been in use for nearly 40 years before the common home models. Since the 1940s, the freezer-on-top-and-refrigerator-on-bottom style had been the common model until the pattern was broken by modern refrigerators. Most household refrigerators, refrigerators–freezers, and freezers use a vapor compression cycle. New refrigerator models  include automatic defrosting, cold water, and ice.

Domestic refrigerators and food storage freezers are manufactured in a variety of sizes. One of the smallest refrigerators of the Peltier type is designed to cool beverages. A large domestic refrigerator is as tall as an person and with a capacity of 600 L can be about 1 m long. Refrigerators and freezers can be standing freely or installed in a kitchen. The fridge makes it possible for the modern household to keep food fresh for longer than before. Freezers allow people to buy and consume food in bulk at leisure, and purchases in bulk saves money.

Lets go into some detail about the parts which help in refrigeration process:

Expansion valves:

An expansion valve, also known as the flow control system, controls the flow of the liquid refrigerant (also known as the coolant) into the evaporator. It is in fact a very small device that is sensitive to changes in the temperature of the coolant.


The compressor consists of a motor from the evaporator that ‘ sucks in ‘ the refrigerant and compresses it into a cylinder to create a cold, high-pressured gas.


This is the part that cools the stuff that was stored inside a fridge. It consists of finned tubes (made of high thermal conductivity metals to maximize the transfer of heat) that absorb heat blown by a fan through a coil. The evaporator absorbs heat from the material kept inside, and the liquid refrigerant becomes vapor as a result of this heat.


The condenser is made up of a coiled sets of external fins tubes and is positioned at the rear of the Fridge. It helps in the gaseous refrigerant’s liquefaction by absorbing its heat and then expelling it to the surroundings.

As the refrigerant’s heat is removed, its temperature drops to the temperature of condensation and changes its state from vapor to liquid.


It’s the water that holds the refrigeration cycle going, often commonly referred to as the coolant. Yes, it is a specially designed chemical that can vary between being a hot gas and a cold liquid.

Fluorocarbons, especially CFCs, were a common choice as a refrigerant in the 20th century. Nonetheless, more environment friendly refrigerants such as ammonia,R-290, R-600A etc are replacing them.

How Does a refrigerator (fridge) work?

There are five basic components in the cooling cycle: liquid refrigerant; a compressor which regulates coolant flow; the condenser coils (on the outside of the refrigerator); the evaporator coils (on the inside of the refrigerator); and something called an expansion machine. Here is how they cool your food:

1) The compressor constricts the coolant vapor, increases its pressure, and drives it into the coils on the outside of the cooler.

2) Hot gas becomes liquid as soon as it comes in contact with the chilled kitchen  air temperature

3) The refrigerant now cools down at high pressure in liquid form as it flows into the coils inside the refrigerator and the fridge.

4) In the fridge, the refrigerant absorbs the heat, cooling down the air.

5) Finally, the refrigerant evaporates into a steam, then flows back to the compressor, where the whole cycle begins.

So i guys i hope i have answered you question about how does a fridge work. Please donot forget to share & comment below 🙂


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