Ventilation is the process of removing contaminated air from the living quarters and delivering fresh air in its place. Gravity ventilation (also called natural) operates using the temperature difference, and thus the pressure between the room and the atmosphere. Ventilation is needed because the air in all rooms constantly becomes contaminated. The air passing through the ventilation grille will be let out through chimneys into the atmosphere.
The need is huge, because now days natural ventilation is unstable. The instability means excessive air ventilation and the return of the air from the ventilation duct (i.e. reverse draft - when it blows from the grille). Reasons for this include:
The effects of this instability are energy losses - financial and health, as well as some inconvenience in the comforts of living.
Insulated building: losses account for 57.1% of all possible losses and it is - 28.108 MJ.
Not insulated building: losses account for 35.1% of all possible losses - 33.816 MJ.
On average, we need 7828 kWh to warm the cold air from the ventilation, and this is from 1400 to 1700 kg coal during the heating season.
Energy losses arise from the fact that the new air flowing in must be constantly heated up. There are also returns of cold air from the ventilation duct (reverse draft), which further cools our rooms. It all gives higher heating costs.
Sealing the ventilation grille with tapes or closing the so-called blinds in winter, to eliminate reverse draft and prevent excessive air extraction is very common, but dangerous to the health of residents. Polluted air - CO2, moisture, vapors, gases must be continuously let out from the room.
The air returning from the duct also carries other surprises, for example smoke, smells, additional moisture and above all mold and fungi spores that can contribute to the deterioration of our health. About million different types of molds and fungi are located in the ventilation ducts. It is hard to argue with the statistics, especially in houses or blocks where they were cleaned a long time ago.
The invisible symptoms include:
frequent headaches, fatigue
irritated mucous membranes
We believe that what is in accordance with nature, is better for a man. It does not need electricity, which is part of our vision of energy saving. It is cheap, and therefore more accessible to people. We believe that natural ventilation has the potential and its discovery became one of our missions, even more so because it is commonly used in Poland and in the world.
Auto-active grille is a natural ventilation system support through its stabilization. The patented design by - physicist Janusz Bielski - supports the discharge of polluted air into the atmosphere. Auto-active grille uses Bernoulli's equation of gas flow, which was also used, for example for power systems for internal combustion engines or fountains. The grille holes are constructed conical. This means that the surface of the hole input is at least 10 times greater than the output. The air will be discharged into the air duct more optimal and evenly.
In short, Bernoulli Law is based on the two main assumptions. The principle of mass conservation (the amount of gas entering the funnel must be equal to the amount of gas coming out of the funnel, regardless of its diameter), as well as the law of conservation of energy (the sum of the potential and kinetic energies must be constant).
In the room (e.g. bathroom) is pressure P1, and the in duct is lower pressure P2. The gas flows from higher pressure to lower, so the air will flow into the auto-active grille at speed V1, and will depart at speed V2. In accordance with the principle of conservation of mass, for the amount of air entering to be equal to the amount of air coming out, the speed V2 will increase (V2> V1)
This principle can be understood by imagining people walking in the tunnel. Where the tunnel is wide they can go slowly next to each other, because they have more space. When the tunnel begins to narrow, they will have to move faster and faster, so that the amount of entering is equal to the amount of leaving.
Let's examine the reverse situation. Pressure in the duct is higher than in the bathroom, so we can say "it blows out of the grille," or it is phenomenon of reverse draft. The diameter of the hole on the side of the air duct is small, so small amount of air passes through it, and additionally, with its enlarging the air slows down. We should also note that the core of the auto-active grille is made of insulating material, which is the value of the system because it does not transmit the low temperature to the interior of and does not cause condensation of water vapor on the surface. This is very helpful in maintaining proper humidity.
The only indicator of the usefulness of a ventilation grille is the quality of air that it holds. Our research shows that by using the auto-active grille, the air quality improves. We have considered three factors, and the investigation room was the bathroom:
After applying the auto-active grille:
the room temperature rose
humidity decreased and remained at an appropriate level - the optimal level is 40 - 60%
the content of carbon dioxide (CO2) decreased to normal level (800 - 1600 ppm - clean air)
Of course, remember to provide a source of fresh air to your room. In the absence of a supplying unit we recommend the use of micro-ventilation in the windows. We also suggest a short but intense airing.