Refrigerator is a piece of household equipment which helps to keep the food cold and fresh for a longer period of time. The fundamental reason for having a refrigerator is to slow down the activity of bacteria that spoils the food. The most common methods of food preservation used today are refrigeration and freezing.

The basic parts of any refrigerator are the compressor, heat-exchanging pipes inside and outside the units, i.e. coiled or serpentine set of pipes, expansion valve and the refrigerant, i.e. liquid evaporating inside the refrigerator and creating the cold temperature.

What is the "weeping" refrigerator defrost mode? "Weeping" refrigerator defrost mode is applied to a high number of refrigerator models, however it should be noted that this mode is applied only to the refrigerator unit and not the cooler. Refrigerators of this mode type contain a vaporizer that vapors the freeze integrated at the back wall of a refrigerator and a run down tray at the bottom. The temperature in a refrigerator unit is always set up to a plus temperature, therefore, when the compressor gets working, the back wall is being frosted. In a certain amount of time the compressor terminates its operation and the settled frost starts melting, the water drops run down to a tray subsequently getting its way to a lid placed on the compressor. Once the compressor starts its operation again, this moisture is being evaporated.

Any refrigerator defrost mode has a few disadvantages. First of all, this defrost mode can be used only for the refrigerator unit, whereas the cooler is to be defrosted manually (you need to switch it off, wait till it defrosts, to carry water). Another disadvantage is the run down tray, which gets blocked after a certain amount of time or is being covered with delivered products, thus, the water gets to the products which can have effect on its spoil.

Currently, refrigerators are manufactured with either electronic or mechanic control. When it comes to mechanic control, it should be noted that it is not only the easiest one but also the most popular version. The basis is a simple thermostat that we scroll but do not have a possibility to set a certain temperature. Instead we choose the freezing levels, for example, 1, 2, 3, 4, 5. There is no tight connection between a certain level and the set freezing temperature. Contrary to mechanic control, electronic control gives a chance to set up a precise temperature (in degrees) for your refrigerator and cooler. Control of this type is normally available at the front of your refrigerator in the control panel. The advantage of electronic control is that in most cases you will be able to set one temperature in your refrigerator and other temperature in the cooler. If the control is integral, the temperature mode is selected at the same time which means that if you change the temperature of your refrigerator, the temperature in the cooler also changes. For this reason, it is handier to have separate modes for your refrigerator and cooler.

So what happens to the products when they get refrigerated or frozen? Refrigerator has two main characteristics: temperature and moisture. These factors have a different effect on a variety of products. Most products are made of water, therefore, when they get frozen, the ice crystals damage its structure and lots of vital materials get lost when the products are being defrosted, whereas the product activity required for the long product preservation is being stopped. A similar situation happens when your refrigerator temperature does not drop below zero degrees Celsius. The difference at this stage is that the vital activity of the product is not completely stopped, whereas the use time of the product gets shorter without loosing the vital nutritive materials.

Modern technologies offer four main product storage methods. The standard temperature in the cooler is from twelve to twenty four degrees below Celsius. The temperature in the unit of a refrigerator is around six degrees above Celsius. The zero mode is when the temperature is set to zero degrees Celsius. Quick freezing happens when the temperature drops to thirty six degrees below Celsius in just more than ten minutes.

So how does the refrigerator control work? The principle of refrigerator control is the cooling agent (the operating refrigerator material with a boiling temperature from fifteen to thirty degrees below Celsius) which means that it circulates in a closed system, gets boiled in the presence of low pressure and takes the heat from the cooling product as it evaporates. The main cooling agent is chlorofluorocarbon which has the lowest boiling temperature of minus one hundred and fifty degrees above Celsius. Some time ago, there has been discussions taking place that chlorofluorocarbon makes harm to the ozone layer due to its constituent parts such as chlorine but now it has an integrated CFC Free Technology which eliminates the harmful components.