While buying a fridge you come across many options to select. It becomes increasingly painful task to select the best for you. One of such option is direct cool fridge and frost free fridge.
Here today we will discuss some interesting facts about direct cool fridge in details. First we will discuss about background of technology and its mechanism to give you clear idea about it.
We will discuss about direct cool fridge under broad headings say:
- How does a fridge works?
- How the food is cooled in the fridge?
- What does direct cool fridge mean?
- What are benefits of direct cool fridge?
- What are disadvantages of direct cool fridge?
How does a fridge works?
Obviously everyone of knows fridge cools the the items kept inside. It is so simple. Let us see how does this magic happens.
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.
How the food is cooled in the fridge
As in above discussion we saw fridge with its compressor mechanism transfers the heat energy from the inside to outside.
This heat energy flow reduces temperature inside. The objects kept inside the fridge still have high heat energy so high temperature than there surrounding.
Here the heat energy flows from high temperature to lower temperature in the inside environment of the fridge. Thus the temperature of the items kept inside the fridge is lowered and they become cold.
Thus this step is dependent on step one.
What does direct cool fridge mean?
As shown in above image there is a cooling plate inside the fridge. This plate becomes cold first by above mechanism.
Next the important law is cooler the air becomes heavier it becomes. The heavy weight cool air goes to bottom of the fridge replacing the hot air below. Hot air coming in contact with cooling plate again becomes cool and heavy and goes to bottom.
Thus this cycle of cooling inside of fridge occurs by law of heat energy. This is called as direct cool mechanism as no specific effort taken to spread coolness inside the fridge.
Thus in direct cool fridge the convection current is created inside the fridge to lower the temperature inside the fridge.
With air getting cooled at cooling plate it condenses moisture at that place. This moisture is turned into the water and then ice on cooling plate. Thus ice accumulates on and around cooling plate in the direct cool fridge. When fridge is opened again new moisture enters along with fresh air and thus the accumulation of ice continues to occur as the fridge continues to work.
What are benefits of direct cool fridge?
Direct cool fridges are in use since a century and still continue to work with same mechanism with few modifications. Let us see how it survived such a long time still to be used. Here we will discuss benefits of direct cool fridge.
- Direct cool fridges consume less energy: Yeah you read it right. Though older technology it may sound they do consume less energy than frost free fridge. This is because the convection currents are used rather than fans to operate inside the fridge.
- Direct cool fridges are cheaper to make and operate: Direct cool fridge is cheaper to make as it uses the simple technology with comparatively few components inside. As there are no fans and convestion current is used to make inside cold they consume comparatively less energy and and so less electricity bills. So they are cheaper to operate too.
- Direct cool fridges are available in many sizes from small 50 litres to large 250 litres. Wide range of sizes are indeed available.
- If any technical fault occurs any mechanic with basic knowledge of fridges can fix it as direct cool fridges operate on simple mechanism.
- Direct cool fridges are durable in long run with good maintenance and care. They can last for 20-25 years too.
- Direct cool fridges need minimum maintenance cost too no frequent out of work condition.
- Direct cool fridges usually come with long warranty of 5-10 years for the compressors. So here they come with such a long warranty that is good for the buyers. The buyers just need to go through the terms of warranty before buying.
- Direct cool fridges are produced by many old, good and trusted brands who have experience of more than 50 years of producing such machines.
- The cooling is faster.
What are disadvantages of direct cool fridge?
As we know frost free fridges were invented later there were some disadvantages of direct cool fridges so there was need to invent further.
Let us here see what are disadvantages of direct cool fridges?
- Frost and ice accumulation: As we saw above in mechanism of cooling the air is cooled at cooling plate in direct cool fridges and humidity condenses there which form ice. The ice is accumulated on the cooling plate. This ice is needed to be removed with manual defrost after every few days.
- Cooling effect: The cooling effects which is dependent heavily on the convection currents the cooling is slow to occur and non uniform. It cools more at cooling plate in freezer but less at the bottom. The cooling is faster but it is inefficient in direct cool fridges.
- Ice accumulation: Ice accumulation on cooling plate can hamper the cooling effect. The ice is heat resistant and it forms insulation and cooling plate. Thicker they layer of the ice less the efficacy of the cooling plate is less in the direct cool fridges.
- Usually available only in single door fridge form. So all the disadvantages of single door fridge are applicable to this fridge.
- Usually direct cool fridges are available up to size 250 litres. If the need is bigger than this size then direct cool technology does not work. So limitation of size is there above 250 litres.
- The water can spill on items stored inside while defrosting the fridge. This can ruin some items which are to be kept moisture free.
- During manual defrosting in direct cool fridges as temperature rises drastically some items can not be stored for long.
- Direct cool fridges fridges can not store items for long some items can get ruined rapidly in direct cool fridges.
- Some form of mold can grow in the ice. So again ice accumulation goes against the favor of direct cool fridges as very few people would like to see molds in there freezers.
- The air inside direct cool fridges is not moving rapidly and so some items if stinking other all items may start sinking with that odor.
- As freezer also exposed to room air every time fridge is opened the temperature in freezer can increase to undesirable level.
- Freezer can not be opened without opening the entire large door of the fridge.
- Even if cheaper price direct cool fridges too cost money with few bucks more you can buy better frost free fridges.
- Being older technology and cheaper cost direct cool fridges may not look very attractive to young generation who co-relates technology and high price with status symbol.