At times, we might wonder how a refrigerator works? A refrigerator works by using a process called refrigeration to transfer heat from the inside of the fridge to the outside, thereby keeping the interior cool. It uses a cycle of compression, condensation, expansion, and evaporation to achieve this. Let’s break down how this process works step by step:
1. Refrigerant
The core of the refrigeration process involves a refrigerant, a fluid with a low boiling point that easily transitions between liquid and gas. Modern refrigerators often use eco-friendly refrigerants like R-600a or R-134a. The refrigerant flows through a closed system within the fridge and is responsible for absorbing heat from inside the unit and releasing it outside.
2. Compressor
The process begins with the compressor, which is typically located at the back or bottom of the refrigerator. The compressor squeezes the refrigerant gas, increasing its pressure and temperature. This high-pressure, hot gas then moves to the next stage of the cycle.
3. Condenser Coils
After leaving the compressor, the hot refrigerant gas passes through the condenser coils, usually found at the back or underneath the fridge. As the refrigerant moves through the coils, it releases its heat into the surrounding air, thanks to the metal coils that dissipate heat efficiently. Consequently, the refrigerant cools down and turns into a high-pressure liquid.
4. Expansion Valve
The next stage involves the expansion valve (also called a capillary tube or throttling device). The liquid refrigerant passes through this valve, which reduces its pressure dramatically. As a result, the refrigerant cools down even further and enters the next phase as a cold, low-pressure liquid.
5. Evaporator Coils
Once the refrigerant is in its low-pressure liquid state, it flows through the evaporator coils located inside the fridge, typically behind the freezer compartment. As the cold refrigerant moves through these coils, it absorbs heat from the air inside the fridge. This causes the refrigerant to evaporate and turn back into a gas. At this stage, the inside of the refrigerator becomes cooler because the heat has been transferred from the interior to the refrigerant.
6. Cycle Repeats
Finally, the now gaseous refrigerant returns to the compressor, and the entire cycle begins again. This continuous loop of compressing, condensing, expanding, and evaporating keeps the inside of the refrigerator cool, while the heat is constantly pushed outside.
Other Key Components
- Thermostat: The thermostat controls the refrigerator’s temperature by regulating when the compressor turns on or off. If the interior temperature rises above a set point, the thermostat activates the compressor to start the cooling cycle.
- Fans: Refrigerators often include fans to circulate cold air throughout the interior compartments, ensuring uniform cooling.
- Defrost System: In frost-free refrigerators, the defrost system prevents ice buildup on the evaporator coils. It periodically melts ice using a heating element, and the resulting water is drained out of the unit.
How a Refrigerator works- Summary of the Process:
- The compressor compresses the refrigerant, turning it into a high-pressure, hot gas.
- The gas moves through the condenser coils, releasing heat and turning into a high-pressure liquid.
- The liquid passes through the expansion valve, where its pressure and temperature drop.
- The cold liquid refrigerant flows through the evaporator coils, absorbing heat from inside the fridge and cooling the interior.
- The refrigerant evaporates into a gas and returns to the compressor to repeat the cycle.
This continuous heat transfer process is what keeps the interior of a refrigerator cool, preserving food and beverages.