~~~~~Introduction~~~~~

I have an ancient, 20-plus year old fridge freezer that is not showing any signs of its age, except perhaps in its outward appearance. I would love a new one, but old faithful is such a trooper I have not the heart to retire it.

The trouble is it does require defrosting every now and again, typically when I have foodstuffs in it, which really should remain cool at all times, like milk or cream, which would go off at the drop of a hat given half a chance.

It was during the summer that I experienced most difficulty in keeping foods fresh whilst defrosting the fridge. A cool box was one solution to the problem, which I had used until, in 2005, I discovered the Mini Fridge.
Since then, I have managed to keep perishables fresh whilst old faithful defrosts.

I had seen these little fridges in Woolworth when they first arrived, designed to cool small cans of coke or lager; my 2litre milk bottles were far too big to fit into them.

Then one day on one of the shopping channels, I saw a larger capacity mini fridge and purchased it for around £28. I have since seen them on Amazon reduced from £69 to £49 and on eBay for £10.

~~~~~My Mini Fridge~~~~~

The outer casing of the mini fridge is white plastic, pretending to be enamel, with its power switches and cable sockets on the back. On the top of the unit is a carry handle, which folds neatly into a recess when not in use.
Two power cables were supplied, one for use with a 12V battery and the other to power from the 220 -240V mains.
Its power consumption is 48 watts.
Maximum obtainable temperature is around 65 degrees Celsius
Minimum obtainable temperature is around 7 degrees Celsius

Dimensions:
The capacity of this little fridge is 15 litres; it weighs 9 lbs, which is a little over 4 kg.
The external height is 42cm, depth, 33cm and width, 27cm.

This fridge can be used to keep foodstuffs warm or cool. - clever eh?

Inside the fridge is a shelf, which can be removed to make more room for tall bottles. On the door is a shallow shelf to hold small loose items such as eggs or butter.

As any who has read my reviews will know, my inquisitiveness knows no bounds, so it will be of no surprise then that I wanted to know what the difference was between the mechanisms cooling a regular fridge and that of the mini fridge. I wondered why, since the outcry about using HFCS and their apparent detrimental effects on the ozone layer in regular fridges, that the alternative mechanisms used in mini fridges had not replaced the original.

Here follows a brief summary of my discovery, for all whose curiosity matches mine - you lose nothing by skipping to the "opinion," if you could not care a tinker's cuss how they work, as long as they work.

~~~~~How a standard fridge is cooled~~~~

A standard fridge is cooled using a refrigerant - usually HFCS which are hydroflurocarbons. The principle being, that heat flows from hot to cold. The temperature of the refrigerant is lowered by turning some of it from liquid to cold vapour via an expansion device. As it passes through the inside of the fridge, heat is transferred from the cabin to the vapour mix, which then passes to the outside of the cabin where it is compressed to raise its temperature again so that the heat will flow from the heated refrigerant to the cooler air - the cycle then begins again.

~~~~How a mini-fridge is cooled or heated ~~~~~

The mini fridge is cooled by using what is known as a "Peltier" device - named after its inventor. In principle, it is a very simple device whereby heat is transferred from one side of a sandwich-like device to the other when an electrical current is passed through it. I was intrigued enough to investigated further, not having ever heard of it before.

It can be demonstrated by connecting two strands of copper to the two poles of a battery and the other ends, one each side of a bismuth/iron plate. At the junction where the current flows from copper to bismuth, it gets hot, but at the junction where the current flows from bismuth to copper it gets cold. One junction is situated outside the fridge cabin, the other inside. An external fan dissipates the transferred heat .
When the polarity is reversed, the cabin will be heated rather than cooled. A switch on the outside will reverse the polarity if required, making this a duo-functional item.

There are two main reasons why the Peltier system of cooling is not used in standard fridges, the first is that the fridge would be using power constantly; the fans would be operating 24/7, making it a tad noisy in comparison. The second reason is that the minimum temperature that can be achieved is around 7 degrees Centigrade, whereas normally a fridge is kept at around 4 degrees.

~~~~~My experience and opinion~~~~~

When 'Old faithful' needs defrosting, I place some of the ice packs inside the mini-fridge cabin just to start the cooling process and switch off my old fridge. Once the mini is switched on and the cool option selected, it takes a few minutes for the cabin to cool down to a reasonable temperature. I then transfer my perishables to the mini and allow Old faithful to defrost naturally.

The capacity of the mini is 15 Litres, and will hold, when the tray is removed, two 2 litre bottles of milk, eggs and butter with room for one or two other small items if need be. I have only needed to keep my dairy products and an open tray of dog food cool for the duration.

The defrosting process usually takes several hours, so the little mini whirrs away keeping my food from deteriorating before the main fridge is ready for use again.

I believe that it was probably designed for campers or picnickers, for it can be powered by connecting to a car cigarette lighter socket. I just use it as a spare fridge and have never used it to keep anything warm, although I can imagine it would be very useful in the winter when travelling to keep pre-heated snacks warm. I certainly could have used it as such when driving up to Scotland decades ago, but they hadn't been invented then. Since purchasing a new fridge freezer with the old one still humming away, my mini fridge is having a rest, but it will still have its uses in the future, I'm sure.