What is ventilation? Why ventilation is needed?

To understand why ventilation is needed, imagine for a moment the situation when a person is put in a tight transparent cube of a certain volume and observe what will happen. Obviously, after a certain amount of time, more or less, the person will become hot, stuffy, and then generally get poor breath and she will beg to be released from the outside.

If our dwellings or any other premises were similar to this cube, then they would have become completely unsuitable for living in them or evena short stay there. For man, as well as all living things on earth, created by God, air is the most important element in his physical life. People, all kinds of animals inhale it, plants are absorbed through their tissues, and even underwater inhabitants in one way or another absorb the air dissolved in water. Undeniable is the fact that without air the person can live on the orders of less time than without light, food or water. An important role for human life is played not only by the presence of air, its quantity, but also its qualitative composition, with certain proportions of oxygen, nitrogen and other elements of water vapor.

So why still need ventilation?

A person, in the process of his life, breathes air by absorbing oxygen and other elements through the lungs and exhaling it with another composition, where carbon dioxide is prevailing. In addition, the human organism can allocate heat and moisture to a certain amount, and other products of gas, steam, dust, smoke and various aerosols and odors may also be products of various types of its activities.
With relative airtightness of the room, the concentration in the air of all the above-mentioned secretions increases and can reach values ​​that are harmful or even dangerous to the health of people in it.
In addition, the increased concentration of vapor in the air, that is, its relative humidity leads to the loss of condensation on windows, slopes and even walls and, consequently, to the development of various harmful bacteria and fungi.
To dissolve harmful substances and moisture in the air to allowable concentration and require ventilation, - inflow into the room of fresh air to replace the removed contaminated. Actually, speaking popularly, ventilation of the premises is the process of replacing the exhaust air in it fresh, from the street.

From ancient times and until recently, ventilation was provided mainly by natural way, the inflow of fresh air - due to looseness in windows, doors, gaps, and hoods - through channels in the walls and in the mines. In recent decades, when as a result of the rising cost of heat-carriers the premises are densely sealed and sealed to reduce heat losses, the natural inflow of fresh air is minimized, and in the absence of it, the natural extract can not actually work.
Therefore, in such a situation, the most appropriate is ventilation with mechanical induction, ie ventilation using such equipment as fans. There can be various combinations of the equipment of this equipment - for example, the inflow and extractor are carried out by fans, or fans are installed only on the extractor, and fresh air is sucked through various devices on windows, doors or through air vents in the walls, and so on. By the way, even exhaust fans, if they are, without a natural influx of fresh air due to the high airtightness of the room, will work in a dark, idle state.
To provide a normal microclimate in the room, the inflow of air, which is served by a forced method, is to be cleaned and heated, which also includes special components. And if it is necessary to carry out the distribution or air in various areas of the premises or in different premises, air ducts and grates are used.