An internal heat exchanger assembly for an air conditioning system, having a housing defining a cylindrical with opposing ends. The ends are sealed with end caps having inlets/outlets. A helical coil tube is coaxially disposed within the cylindrical cavity, in which the helical coil includes two tube ends extending in opposing directions and exiting the cylindrical cavity through tube ports provided in the end caps. A twisted elongated strip is coaxially disposed within the cylindrical cavity extending from the first end to the second end. The twisted elongated strip includes a plurality of radially extending fingers adapted to engage the helical coil to maintain the helical coil in a predetermined position.