Abstract: An assembly of a slot(35) in a bottom wall (21) of a flue (10) in immediate conjunction with a compartment (25) in which a stack of layers (33) of fibrous material is deposited or stacked for absorbing grease (13) from a passageway of a venting housing (13). The vented air (14) and grease (13) flow to flue (10) by an independent force for generating such flow. As the vented air (14) and grease (15) reach flue (10) the air continues to flow through flue (10) to discharge through the latter's escape opening (19) while grease (15) drops through slot (35) onto the top one of a stack of layers (33) of fibrous material in compartment (25), thereby removing the problem of an accumulation of grease (15) on a roof or base (40) over which compartment (25) is located, thereby averting the need for repair of or installation of a new roof or base.