Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, heat exchangers, and multichannel tubes are provided which include internal configurations designed to promote mixing. The multichannel tubes include interior walls which form flow channels. The interior walls are interrupted at locations along the multichannel tube in order to provide open spaces between the flow channels where mixing may occur. The mixing that occurs promotes a more homogenous distribution of refrigerant within the multichannel tubes.