Unfortunately, it often happens that the ventilation in our homes does not work properly, which may be indicated by the so-called reverse thrust. Air blowing forcefully into the house through the grille can irritate many home owners who associate it with the fact that their windows steam up significantly and growing spots of fungus form under the settling moisture. Very often, they end up making a wrong diagnosis by sealing the ventilation grille so that less air is blown into the room.