Abstract: Heat absorbing sheet sections with corrugated surfaces terminate in part cylindrical flanges. The flanges are pressed between spaced heat collection tubes and held in place by spring action. The combined structure forms a heat absorbing surface and is secured within a pan having integral bottom and upraised sides. A seal molding is secured on the upraised sides of the pan and mounts two glass panels over the heat absorbing surface. A peripheral slot is formed in the seal molding. A key is pressed fit into the peripheral slot to hold the glass panels and molding in position.