Traditional Chimneys with Casette filter has a Disadvantage---Filter obstructs the suction & frequency of cleaning the filter is more in these chimneys and Service required is also more frequent.As it obstructs the flow, suction reduces by 150-200m3/hr.For example, a chimney with casette filter of 1000 suction, actual efficiency would be only 800. Baffle filter Chimneys are Litte better than casette filter chimneys, As it reduces the frequency of service and cleaning is reduced to an extent.But Efficiency is certainly reduced. Baffle filter with Autolean are recent Advancements, But still have filters, which needs to be cleaned. Advanced chimneys are Filterless Autoclean-1st gen autoclean, 2nd gen autoclean and 3rd Generation Autoclean. 3rd Generation autoclean chimneys are without filter and Has a use of german technology, has a chamber collects oil and Efficeincy is More as No filters are there and No hassles of Cleaning filter.Just PUSH OF A BUTTON, Oil gets collected ...