How does a refrigerator work

If you’re like other people, you don’t worry that much about your refrigerator’s inner working mechanism until it breaks down, or it’s time to fix it.

However, it can be helpful to know exactly how it keeps your food cold and get the most out of this indispensable appliance — we at Tech Insider 360 ° are here to guide.

This article intends to help you learn what you need to know about how does a refrigerator work and how it helps keep your foodstuffs cold.

The refrigeration process helps freeze water, produce ice cream, and delicious frozen yogurt. It helps preserve your fruits, vegetables, and other types of food.

The edible products get destroyed at an atmospheric temperature as under these conditions bacteria can easily survive. Bacteria cease to exist at temperatures below 4 degrees Celsius, and therefore the products remain healthy and fresh.

What are the main components?




The compressor acts both as a motor and a pump that pushes the coolant through the machine. When the temperature rises above the set point, the sensors signal the compressor to start.

No cooler is completely airtight; cold air escapes out, and warmer air gets in, allowing the temperature to rise above its set point.

Condenser coils


In a refrigeration system’s cooling process, the vapor refrigerant absorbs the heat, followed by the compressor compressing the refrigerant.

The vapor refrigerant’s high pressure and the high-temperature then converts it back into a liquid. It helps to condense the compressed refrigerant vapor efficiently.

There are essentially three types of the condensing device depending on how the condensing medium, which is usually water, gas, or both, extracts the heat that the refrigerant absorbs.

Air-Cooled condenser

Typically these are used in the application for residential and small offices. They are used in systems with a limited capacity of under 20 tons.

Air-cooled condensers’ benefits include not needing to do water piping, not requiring a water disposal system, saving in water costs, and not having much scaling problems caused by the water’s mineral content. Installation is also faster and has lower initial costs.

Water-cooled condenser

Three forms are widely used. They all are shell and tube, coil and pipe, and double tube. The shell and tube type are the most commonly used and are generally available from two tons up to a few hundred tons.

This design has lower power demands per ton of cooling, and compressors will last longer than the air-cooled form.

Evaporative condenser

The transfer of heat in evaporative condensers is similar to that of air-cooled condensers, with the exception of the difficulty of mass transfer due to evaporation on the tube ‘s surface.


It is in the evaporators where the real cooling effect in the refrigeration and AC systems occurs. The evaporator is a crucial component, and they view other parts as less critical.

Expansion Device

The expansion device aims to reduce the refrigerant pressure during the refrigeration period quickly. This allows the fast cooling of the refrigerant before entering the evaporator. There are three types of expansion devices:

1. capillary tube

2. thermal expansion valve (TXV)

3. electronic expansion valve.


Usually, thermostats are located inside the fridge and have a knob that allows users to change their temperature.

If a consumer sets the desired temperature, the weather is controlled by the thermostat by regulating the electricity flow to the compressor.

If the thermostat is the brain, the center of the process is the compressor, which pumps the refrigerant through the coils.

The thermostat ceases electricity to flow to the compressor when the refrigerator’s interior is at the desired temperature. This allows electricity to flow when the thermostat feels too much heat, triggering the compressor.


Refrigerant R600a

It’s the liquid refrigerant that keeps the refrigeration cycle running, often widely referred to as the coolant. It is a specially formulated chemical which can vary between being a hot gas and a cold liquid.

Fluorocarbons, particularly CFCs, were a popular option as a refrigerant in the 20th century. However, they are replaced by more environmentally friendly refrigerants like ammonia, R-290, R-600A, etc.

The Defrost System

The defrost system helps to remove the excess ice from the evaporator floor. The thermostat button may manually control the defrost mechanism, or an automated system consisting of the electric heater and the timer.

These were some of the domestic refrigerator’s internal components; now let us see the outer parts.

Freezer compartment

The freezer compartment stores the foodstuffs at freezing temperatures. The temperature here is below zero degree centigrade. Water including many other fluids usually gets frozen at this temperature.

They must be kept in the freezer compartment if you want to make ice cream, ice, freeze the food, etc.

Thermostat control

The thermostat control consists of a round knob with a temperature scale that allows us to set the appropriate temperature.

It is essential for keeping the correct refrigeration cycle. Proper thermostat setting, as per the requirements, will help save loads of energy bills for refrigerators.


The largest part of the refrigerator is the compartment. All food products that are to be held at a temperature above zero degrees Celsius but in a cooled state are stored here.

The fridge compartment can be divided into various smaller shelves, such as a meat keeper, and others as needed.

The heating and cooling cycle


When gas is compressed into liquid, heat is released. When liquids expand to become gases, heat is absorbed. This physical mechanism is used to eject heat from the inside of the refrigerator to the outside.

This is achieved inside the refrigerator by always heating, evaporating, and condensing a closed system’s fixed refrigerant supply.

Evaporation occurs at low temperatures and low pressure, and high temperature and high-pressure condensation occur.

Thus, heat may be moved from a quiet temperature area ( i.e., within the refrigerator cabinet) to a high-temperature location ( i.e., kitchen room), thats how a refrigerator works. The refrigeration cycle is maintained this way.

Why does it take longer to cool inside the fridge?

The foodstuffs contains plenty of water, made of very lightweight molecules. Even a small quantity of water-based liquid (or solid) contains many molecules, each of which takes energy to heat or cool off.

This is why boiling even a cup or two of water takes a few minutes: there are many more molecules to heat than if you’re trying to heat anything like a cup of molten iron or lead pipe.

The same applies to cooling: removing heat from watery liquids such as fruit juice or solid requires energy and time. That is why it takes time to freeze or cool down. This is to help you understand how does a refrigerator work.

Tips to maintain your refrigerator

  • While you may not see the coils, keeping them free from dust, debris, and pet hair allows the refrigerator to run better and more effectively. The coils are typically located at the bottom or in the back of the unit.
  • Frequently check the temperature in both your unit’s refrigerator and freezer parts. This is important for the protection of foodstuffs as well as for making the fridge work effectively.
  • The refrigerator’s compartment should be about 37 to 40 degrees Fahrenheit, and the portion of the freezer should be set at zero degrees Fahrenheit.
  • If your gasket doesn’t seal well, cold air inside will escape, making the device work harder and taking more energy to hold the temperature right. For signs of wear and tear, check the gasket regularly.
  • Many people may not know; that refrigerator ice makers and water dispensers typically have changing filters. For detailed suggestions and replacement information for your model, review your manufacturer’s instructions.
  • Your mother was right as it turns out-keeping the fridge door closed is one of the best ways to ensure proper care of the refrigerator. This is because when the door is opened, the fridge needs to work harder to maintain the right temperatures.
  • The device’s temperature and contents will be increased by putting hot, steaming foodstuffs in your fridge, making the refrigerator more challenging to stabilize.
  • Although food safety is crucial, before putting them in your refrigerator, take a few minutes to let hot products cool down.
  • To remove condensation, most refrigerators rely on a drain hole and a drip tray. Remove any food debris and mineral deposits from the drain hole as guided in the owner’s manual. Then scrub the pan for drain.


  1. If the temperature goes over the setpoint sensors inside the refrigerator, the compressor is alerted to activate, and the cooling cycle begins.
  2. The unit draws, pressures, condenses it in the cold liquid refrigerant, and increases temperature, converting it into a gas.
  3. On the outside of the refrigerator, the compressor moves the hot gas into the condenser coils, where it comes into contact with the lower air temperature in the room and returns to a liquid state.
  4. The cooled liquid continues on its path to the evaporator, passing through the refrigerator compartment’s inside coils and the freezer.
  5. The coolant absorbs the hot air from inside the refrigerator, reducing the temperature to the desired set point.
  6. The refrigerant evaporates, converts back into a gas, and returns to the compressor to continue the cycle.

Fun facts

  • Around 10 percent of the total energy in a popular household is spent in the refrigerator.
  • A refridgerator is more effective when it has more items in it.
  • 15th November is the Annual “Clean Your Refrigerator” Day in the United States. Whirlpool Home Appliances was invented as an advertising product.
  • Back in 1911, General Motors produced the first commercial household refrigerator. Kelvinator was their first successful line, and this model held close to 80 percent of the market by 1923.
  • By 1956, 80 percent of U.S. households had a fridge. That number rose to 99.5 percent by 2005. About 15 percent of American families have two fridges.

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