It is advisable to use plastic disk valves for easy installation and right air distribution in a room. They are user-adjustable from inside the ventilated room and can be mounted into a ceiling or a ceiling void, fitted on a plastic adaptor or on an aluminum hose. The valve diameter depends on the diameter of the ducting and on the size of the ventilated room. In most cases the size is DN 125.
Round grilles can be fitted into a wall.
Round plastic duct shall be fitted into a wall and fixed with mortar. Its outer diameter shall correspond to the hose diameter, usually 125 mm. About 3 cm of the rigid duct shall protrude from the wall, enabling the flexible duct be shifted on it and fixed with metal clamps.