Indicator showing saturation of filter in extractor hoods - operates without maintenance, manual control but according to pressure differentials

摘要

The extractor hood contains an underpressure chamber (3) located behind the fat filter (2) and a ventilator (6) which feeds the air from this chamber to an excess pressure chamber (4). Here, the pressure arising in the underpressure chamber between the non-saturated and saturated filter serves as the value for actuating the sound indicator mechanism (7) which shows when the filter is saturated. This indicator is immediately ready for use once the filter is changed and requires no maintenance. It preferably has a channel housing connected with the excess pressure chamber.