Abstract: A structural building component having an elongated trough like shell with side walls of adjacent components held together by a clamping means that prevents leakage between the panels and hold the panels against endwise movement relative to each other. The panels include solar radiation absorbing means and heat transfer means in the form of tubes which extend completely through the panel so that adjacent tubes in the same panel or in adjacent panels are connected together exterior of the panels with a gutter arrangement to conceal the exterior connections and to accumulate moisture or condensation and leakage, if any, from the connections.