An air distribution conduit (1) for use in a greenhouse defined by an elongated lower end (2) of an elongated cultivation gutter (3) and by an elongated flexible sheet (4) having two elongated side ends (5,6) which elongated side ends (5,6) are connected to the elongated cultivation gutter (3) and wherein the conduit (1) is provided with multiple openings (12,19) along its length fluidly connecting the interior (13) of the conduit (1) with the exterior (14) of the conduit (1).