Abstract: A ventilation unit for a low temperature chamber with a tube-shaped base body, having a heating element, an inlet side end with an inlet opening and an outlet side end with an outlet opening, wherein the base body has a tapered form such that the inlet opening has a greater area than the outlet opening. The inlet opening can be located in a first front side plane and the outlet opening can be located in a second front side plane, wherein the first front side plane and the second front side plane are substantially parallel offset with respect to one another, and wherein at perpendicular projection of the first front side plane onto the second front side plane, the inlet opening and the outlet opening are disposed offset with respect to one another. The base body can have a mechanical valve configured to open under pressure induction.