In previous post we have discussed about direct cool fridge. We have seen in disadvantages that accumulation of frost is a major drawback in those direct cool fridges. The disadvantages lead to invention of Frost free fridge
Are you tired of manual defrosting of fridge? You have large family and many family members so need a large fridge? You want to keep the fresh food items for longer period?
If the answers to above all question is loud ‘YES!’ then definitely you need a frost free fridge. With the benefits these frost fridge too have some disadvantages too.
Let us see how these frost free fridges work, there benefits and disadvantages in details, so that all your queries are solved with ease.
- What is frost free fridge?
- How does a Fridge works?
- Mechanism used in frost free fridge.
- Benefits of frost fridge.
- Disadvantages of frost free fridge.
- Should you buy a frost free fridge?
What is frost free fridge?
As its name suggest when this fridge works the frost and ice does not accumulate on cooling plate like a traditional direct cool fridge.
These are also called as no frost fridge or auto frost fridge as frost does not accumulate in it.
They are available in many sizes from large to small and many types like single door or multiple doors.
How does a fridge work?
In the previous post we have seen how does a Fridge works.
Let us quickly revise how does this magic happens.
Obviously everyone of knows fridge cools the the items kept inside. It is so simple.
As we know cool necessarily means less temperature. Temperature is indicator of heat energy. More the temperature more the heat energy. Less temperature is indicator of less heat energy in the object. By the simple laws heat energy flows from high energy to low energy that is from high temperature to low temperature.
To make energy flow from inside of the fridge which is cooler than environment or simply to flow it even if it is same as environmental temperature so that it can be lowered inside there should be a mechanism that does this work.
Here this mechanism, a compressor is fit with the fridge. When gases expand they do absorb energry from environment to do work of expansion like any other object does while expanding. To expand them they should be compressed at first place. This work of compression is done by the compressor. The gas is compressed in the tubes which are outside the fridge. Then this gas is released in the tubes which are inside the fridge. The gas while expanding there absorbs energy inside the fridge to lower the temperature. Again this gas is sucked and compressed in the tubes outside to release this energy in to the environment.
Thus when this procedure works in continuation a flow of heat energy is created from inside to outside of the fridge in a simple language.
Every fridge has thick insulation that helps to reduce the flow of energy from its wall thus maintaining temperature gradient across the walls.
Mechanism used in frost free fridge.
The above basic mechanism is common to all fridges. Let us see, what is different in case of frost free fridges?
As we discussed in previous post after cooling the cooling plate which contains the evaporator tubes the air coming in contact with the cooling plates cools and goes to bottom of fridge, replacing the hot air below. The convection current of air sets in. The air is cooled and humidity is condensed at the cooling plate causing accumulation of the frost and ice.
In frost free fridge the mechanism is present which prevents the accumulation of this ice. It is done with the use of:
- Heat producing mechanism.
- Fans inside the fridge.
Heat producing mechanism
Heat producing mechanism periodically produces heat with heater which is inbuilt. This heating process occurs intermittently and quickly at set frequency.
This heating melts the ice and also prevents the condensation of humidity occurring at the cooling plate.
During this heat process obviously the temperature of cooling plate can rise for a short period of time. The items inside the fridge which have large mass do not get heated as they will need more energy to do so.
Thus they are spared from getting soiled as there temperature does not rise or rise minimally during this process.
Fans inside the fridge
As we discussed above that the convection current cooling process used in direct cool fridge leads to frost and ice accumulation at the cooling plate.
The frost free fridges come with fans which are operational inside the fridge. So instead of using convection currents of air to cool the items inside the artificial current of air is produced by the fans.
Because of these different air currents inside the fridge the frost does not accumulate in the fridge. The items inside the fridge are cooled in a more uniform way in all the compartments of the frost free fridge.
Benefits of Frost Free Fridge:
With above basic knowledge of basic mechanism used in frost free fridge it will become easy for us to know the benefits of the frost free fridge.
- Auto defrost: As we discussed above like its name indicates these are frost free. No accumulation of ice, so no need of manual defrost.
- Size: Frost Free Fridges can be from small single door to large size even 650 litres size. You can read more about size of fridge by clicking here.
- Many forms: Frost Free Fridge are available in many forms like single door, double door, multiple door forms, side by side door.
- Large families: Frost Free Fridge are suitable for large families too.
- Uniform cooling: The cooling process is uniform in the Frost Free Fridge so items kept near bottoms are also well preserved.
- Fresh for long: The items kept inside frost free fridge stays fresh for long period of time compared to direct cool fridge.
- Less odor: As air is continuously circulating the items kept inside Frost Free Fridge don’t stink like in direct cool fridge.
- Separate doors: In case of multi-door fridge you can open freezer compartment separately without opening the entire fridge. This protects the fridge from large temperature fluctuations and also help to reduce the electricity bill.
- Durability: Frost Free Fridges are durable too.
- Warranty: Frost Free Fridges also come with long term 5-10 years of compressor warranty. The buyers should go through what are terms of warranty before buying the fridge.
- Brands: Many old, trusted, quality proven brands produce frost free fridges now a days.
- Status symbol: Being a new technology and slightly higher cost They may act as status symbol for some families.
Disadvantages of frost free fridge.
Like any other machines, though frost free fridges are preferred as latest technology it does have its own disadvantages too. Let us which are cons or disadvantages of frost free fridge:
- Cost: Producing and operating frost free fridge is costly. As from above discussion we know a sophisticated and equally complicated mechanism is used in these frost free fridges, they cost more money to produce and operate.
- Energy use: Unlike direct cool fridge the frost free fridges loaded with heat producing mechanism and also fans running continuously cause more energy consumption and more is the electricity bill.
- Fridge burn: This process occurs when there is fluctuation in temperature of the freezer compartment and because of that the items kept inside get spoiled. As we discussed above that there is a heat producing mechanism which prevents accumulation of frost in the fridge. During this heat producing process temperature may rise if the mass of the object inside the freezer is less. It may get spoiled.
- Difficult fix: As we know these frost free fridges use sophisticated technology and more mechanical components the fix if needed is done by expert mechanic. Ordinary mechanics may find it difficult to do this job and for the customer it become costly heavy on pocket.
- Failure: As these frost free fridges use more complicated machinery it is more likely to fail than simple direct cool fridge.
- Labs and medicines: These frost free should not be used in the labs and for medicines as the sensitive chemicals may be spoiled with fridge burn.
- Heat: These frost free fridge may heat from outside.
- Water condensation: Water condensation may occur on outside surface of the fridge during the hot humid season.