Involves the adaptation of air change in apartments to current needs. Relative humidity prevalent in the apartments is the factor in decisive for the rate of air supplied and exhausted. The level of humidity in the apartment is directly related to the number of users and everyday works, as a result of which water vapour is emitted (washing, boiling, bathing).
Owing to hygro-controlled grilles, the system allows supplying outside air and ensures the control of the rate of air exhausted - this is the area of responsibility of hygro-controlled exhaust or extraction grilles. Under the influence of the changing humidity, the polyamide tape length becomes longer or shorter, at the same time changing the capacity of the grille. As a result, the air rate that may flow through the element also changes.

REGEL-air� Mouth grille comprises two single elements with width 125 mm each. The ventilation hatchs are equipped with various types of counterweights, through which individual grilles react respectively on the pressure of wind in the order of 20-30 Pa. The REGEL-air� mouth grille is devised such that the area used up is supplied in a controlled way.
In combination with the building ventilation system REGEL-air� operates as the unit supplying the air. The fresh air from outside is supplied to the space between the leaf and the window frame where, initially heated, lifts up and penetrates into the interior of the room through the grille. The phenomenon of air drought is not present as the air from the outside is directed through the grille and the upper rebate to the area under the ceiling where it mixes with the hotter air in the room. The REGEL-air� grille is simple in assembly and doesn�t require any special drillings and milling works. The installation may also be performed in the window already installed.