PURPOSE: To permit to carry the heat exchanger through a small opening by a method wherein collapsible support bodies are provided in parallel with intervals and the heat exchanger of resin, provided with a flexibility, is attached to the support bodies in spread condition so as to show a scrool shape or meandering shape.

CONSTITUTION: The resin pipe 1, capable of being straightened from continuous coil of several ten or several hundred meters and of being bent with a curvature determined in accordance with a requirement, is worked into a scrool type and is fixed to a plurality of supporting rods 2 through pipe fixing fitments 3 at several places so that the curvatures and positions of curved sections are stabilized. The supporting rod 2 is jointed at several places on the way thereof with hinges 4 or the like whereat the rod 2 can be floded. According to this method, the width of the heat exchanger may be narrowed by folding it into two or three folds or the like and, accordingly, the folded heat exchanger may be carried into a tank through a manhole having a diameter smaller than the width of the heat exchanger.