Method of fabricating a solar heating unit

Claim 1

A process of fabricating a solar heating unit for heating fluids comprising the steps of a. placing a thin, soft, annealed sheet having a good thermal conductivity characteristic in an abutting relation to a grooved surface of a self-supporting, thermally conductive planar plate, the sheet being between one-eight hard and fully annealed, b. assembling a plurality of cylindrical elongated hard drawn tubular elements in a spaced apart planar relation, the spacing between said elements equal to the spacing between said grooves, and the contour of said grooves substantially conforming to an attachment portion of the contour of said cylindrical elements, c. connecting headers in a fluid-tight connection to the assembled elements to provide fluid flow paths between said headers and through said elements, d. applying a thermally conductive paste adhesive along said attachment portion of the elements, e. positioning said assembled elements in an aligned relation to the grooves in said plate with said attachment portion abutting said thin sheet, and f. pressing said elements against said sheet with sufficient pressure and temperature to creep form said sheet around said attachment portion of said elements, and to simultaneously melt said paste adhesive to thereby provide a good thermally conductive metallurgical bond between the elements and the sheet.