A gas flow unit includes a gas flow inlet, a gas flow outlet and a gas flow chamber configured to convey a gas flow from the inlet to the outlet, wherein the gas flow inlet is configured to convey the gas flow in a first direction into the gas flow chamber and wherein the gas flow outlet is configured to convey the gas flow in a second direction from the gas flow chamber, wherein the second direction is angular in relation to the first direction, and wherein the gas flow inlet is an inlet into the gas flow chamber and the gas flow outlet is an outlet from the gas flow chamber. In the first gas flow direction, the gas flow chamber extends beyond a projection of an outer periphery of the gas flow outlet and defines a prolongation configured for conveying a first part of the gas flow such that it enters the gas flow outlet from a different direction than a second part of the gas flow entering the gas flow outlet without passing through the prolongation.