A heat pump heat exchanger includes a first manifold, a second manifold spaced from the first manifold, a plurality of refrigerant tubes hydraulically connecting the manifolds, and a distribution tube disposed in the first manifold. The distribution tube includes an inlet end, a distal end opposite the inlet end, a plurality of orifices between the inlet end and the distal end. The distribution tube also includes a terminal aperture immediately adjacent the distal end, wherein the terminal aperture includes an open aperture area greater than any one of the open orifice area. The open aperture area is large enough to provide a uniform refrigerant collection with acceptable minimal pressure drop in evaporative mode, but small enough to prevent vapor overflow to an area of the manifold adjacent to the distal end in condenser mode. The length of the distribution tube is less than 3/4 the length of the first manifold.