Above-roof ventilator has pipe connection on which all-round collar is formed, cover closing top of pipe connection and ventilating apertures distributed on periphery

摘要

The above-roof ventilator has a pipe connection (1) on which is formed an all-round collar (2). A cover (3) closes the top of the pipe connection and on the periphery are distributed a number of ventilating apertures (10), formed as slots. The bottom (11) and the top (12) of the slots are outwardly inclined and on the bottom a heightened step (13) is formed. The step is in the inner area of the slot. The bottom and possibly the top of the slot is inclined outwards by approximately 15 degrees to the horizontal. The wall of the pipe connection is thickened in the area of the slot.