Provided is a highly efficient heating and cooling system. The heating and cooling system is provided with a cooling-purpose heat exchange section that, during cooling, subcools refrigerant, which is discharged from a compressor and liquefied by a heat source side heat exchanger, with an acceleration phenomenon of the refrigerant by rotating the refrigerant helically before the refrigerant reaches a pressure reducing device, and a heating-purpose heat exchange section that, during heating, partially vaporizes refrigerant, which is discharged from the compressor and liquefied by a use side heat exchanger, with an acceleration phenomenon of the refrigerant by rotating the refrigerant helically after the refrigerant has passed through the pressure reducing device and before the refrigerant reaches the heat source side heat exchanger, in which a heating-purpose coiled narrow tube of the heating-purpose heat exchange section has a flow passage that is formed to be wider than that of a cooling-purpose coiled narrow tube of the cooling-purpose heat exchange section.