Everyone knows that food left in the heat spoils faster than the one left in the cold. Under low temperature conditions, bacteria slow down their activity, and chilled foods persist longer than at room temperature. Even in ancient times, people noticed that the products left in the shade persist longer than those that stand in the sun. Also, people saw that in the cold season the shelf life of products is many times increased. Therefore, they began to look for ways to solve the problem of preserving products with low temperatures.
Some dug cellars, because the temperature under the ground is much lower, others obkladyvali products with ice or snow. Even with the hot climate of the desert, people at night cooled the water in which they stored food for the day. All these methods were much inferior to the preservation of products of the modern refrigerator, which appeared many years later.
The oldest ancestor of the modern refrigerator was released on August 17, 1816, but was still of little use for home use. Serial production of refrigerators began in the US in 1925, and in the USSR this subject of household appliances became available to people only since the 1960s. Soviet refrigerators were bulky and little functional, but reliable and easy to maintain.
Since that time, the refrigerator has changed many times. Constantly improved design and technical qualities. To date, their choice is so great that most people often wonder which one to purchase. Now it is possible to choose a refrigerator for every taste, suitable for the interior of the kitchen in color or size, as well as in the class of energy-saving and type of freezing. Modern refrigerators come in two types, drip and dry freezing. The first ones are ordinary refrigerators that require regular defrosting, others do not require such a procedure.
The system of dry frost appeared relatively recently. People often hear the popular word "know frost", which everyone associates with the term dry frost. Although in English this phrase sounds - there is no frost. In these refrigerators, the evaporator is hidden behind the back wall or above the freezer and one or more fans are always present to ensure a constant circulation of cold air, which enters the chambers through special channels. When the refrigerator works, moisture appears, which does not settle on the wall of the chamber with a layer of frost, but covers the coldest part of the evaporator. The compressor is periodically turned off and the hoarfrost, by which time it is covered, is defrosted by a preheated small heater, and the formed moisture evaporates.
There are a lot of rumors about the benefits and dangers of dry frost. But the fact that such a system is already used by the whole of Europe speaks for itself. Such a refrigerator should not be thawed, but many people who use it, and the manufacturers themselves recommend at least once a year, the refrigerator still defrost to ensure that it lasts longer. The products in such refrigerators are cooled quickly and evenly, they also freeze, which ensures the preservation of their kind, taste, useful vitamins and minerals in them. All kinds of berries, greens, fish and meat, many vegetables are suitable for dry frost. The main thing is not to freeze the food again, after defrosting. This way of preserving the products is much more convenient and useful than canning, as it preserves the products without adding harmful preservatives such as vinegar, for example, whose harmful influence on the human body does not need proof.
Many say that refrigerators with the system "know frost" are too noisy through the work of fans. This statement does not apply to all models. Some manufacturers use fans that work very quietly, however, these models are slightly more expensive. Another problem with refrigerators with dry frost is that they drastically dry food to avoid this, you need to carefully wrap the frozen products in a plastic film. Refrigerators with dry freeze consume a bit more energy than refrigerators with a drop system.
Perhaps, these are all known shortcomings of dry freezing. But you will always have the opportunity to surprise guests under the new year with a fresh strawberries collected with their own garden in their garden.