It’s probably baffled many curious minds out there, but why is it that the refrigerator’s freezer area is cooler than the fridge? Why is it that the freezer frosts and forms ice crystals while the rest just stays cool?
To effectively answer this question, we need to deep dive into a refrigerator’s inner mechanisms, how it works, and why it works.
How does a refrigerator work?
The fridge and the freezer are not separated from each other. They are continuous components that are connected by pipes and vents.
This is why when you slam the fridge door, the freezer door partially opens. Some air gets to the pipes and flows upwards to the vents, causing the freezer door to open.
The main principle that the whole refrigerator unit operates on is removing hot air to cool the system. This is done through a process called the refrigeration cycle. Five main components make this possible.
- Expansion device
- Evaporator coils
- Condenser coils
- Compressor coils
These are the steps to the refrigeration cycle.
- The refrigerant enters the expansion device. Because of the high pressure, it expands, cools down, and turns into a gas.
- The evaporator coils then evaporate and circulate the liquid refrigerant as gas to absorb all the refrigeration unit heat.
- After absorbing the heat, the refrigerant is then compressed in the compressor. This raises the temperature and pressure.
- The refrigerant finally reaches the condenser coils at the back of the refrigerator. This is where the heat that is absorbed inside of the system is released. This explains why the back of your refrigerator is hot.
Why is the freezer colder than the rest of the refrigerator?
The whole refrigeration process mainly takes place in the freezer. To put it simply, the cold air “originates” in the freezer. It is the leading site of heat absorption, which causes it to cool down.
The evaporator fan then blows this cold air upwards to the freezer’s back and the whole unit’s top. This air reaches the unit’s refrigerator part via the ducts and vents that connect the two compartments.
In specific, three vents connect the two components. The two vents circulate back the air to the freezer, and only one goes directly to the fridge.
A damper is also in charge of directing and controlling the air that reaches the refrigerator.
In essence, the freezer is colder than the rest of the refrigerator because the cold air originates in the freezer, and only a fraction of the air reaches the fridge.
Air is expanded more in the freezer, which causes it to cool, and this process doesn’t take place in the fridge, but more so, the fridge only shares a part of the air that comes from the fridge.