Abstract: A heat transfer profile has coaxial cylindrical inner and outer peripheries. A cylindrical first space is formed inside the inner periphery. The cylindrical outer periphery has a shape cut on at least one side. Blade-like heat transfer flanges extend between and contact both the inner periphery and the outer periphery. A second space is provided inside the cut part of the outer periphery, defined in part by a section of the inner periphery and two heat transfer flanges. The second space is open at least from the cut side of the outer periphery to the exterior of the outer periphery.