A significant field of technology today deals with the use of solar energy and energy conservation in general. This applies to building construction and design as well as other fields.
There are many different types of systems that can be employed with a building structure to collect solar energy and transfer the energy within the building for storage and later use. Additionally, there are many structural designs employed today which take advantage of maximum control of the heat loss in the winter and heat gain during the summer months. These varied systems are used with all types of building structures. Examples appear in U.S. Pat. Nos. 2,601,905, 2,625,930; 3,145,707; 3,254,701; 3,270,739; 3,875,925; 3,919,784; 3,935,897; 3,957,109; 3,964,678; 3,965,972; 3,986,491; 3,994,276; 4,029,258; and 4,045,880.
To date most "conventional" thinking concerning collection of solar energy to capture it as heat or to convert it to electricity has been of two kinds when applied to habitable or storage structures; solar collectors typically of the flat-plate type or photo-voltaic arrays applied externally to the weather type building enclosure and additional thereto, or "passive" systems which admit sunlight to the interior of weather-tight structures, used directly as ambient comfort conditioning, or collected and stored as heat by circulation of the air warmed by interior building surfaces heated by the sunlight.
In principal, if a solar system can be integrated into the weather-tight enclosure of a habitable or storage structure, it has a dual function. Externally mounted solar arrays do not do this; they must penetrate the structure with piping, ducting, cables or supports or all of these. It is well established in insurance claims and defects remedial work, that weather-tightness problems are by far the largest class of recurring difficulties confronting architects, structural engineers and builders in current building technology.
Therefore, if a building element such as a roof can be constructed as a weather-tight assembly using proven technology with the solar energy utilization devices integrated inside the weather-tight assembly, the difficulties of solar energy integration into structures are greatly minimized.
In addition, since the arc of the sun's passage dictates the optimum orientation and inclination of solar collection devices, usually at angles between 30.degree. and 60.degree. off the horizontal in the conterminous United States, the collector itself casts a "shadow" and gives rise to the "packing factor" which dictates the spacing of collectors, depending on their vertical rise and inclined dimension. If the "shaded" portion of the projected horizontal plane can be used to useful purpose as for instance to admit reflected and refracted "north light" this constitutes a greater utilization of solar energy, as natural illumination.
By placing solar devices to collect solar heat or light energy and to produce electricity by the photo-voltaic process, inside a weather proof structure it becomes manifestly easier to incorporate mechanisms which produce angular rotation of the solar collection surface as the movement mechanisms are protected from the elements and the solar arrays are protected from wind stresses.
Likewise, since the local conditions of external climate can vary immensely in the United States (and throughout the world) through the annual cycle, sets of conditions of temperture, wind, humidity, snow or ice buildup etc, occur which render the admission of natural light or the gain or loss of heat through a portion of a roof structure inadvisable from the standpoint of interior comfort conditions and building operation economics. If therefore an economical means of controlling the heat loss or gain or the admission of direct or reflected sunlight can be incorporated in connection with a "north light" skylight this would increase its economic usefullness as a building element.
Lastly, if the solar collector assembly and insulating devices and their control devices for rotational or pivotal movement would be inside a weather-tight enclosure not subject to wind stresses their design would be structurally lightened and the strength of actuating devices could be minimized to be of low power input; and therefore capable of automation and or computerized programmed control.
Accordingly, a low cost system which incorporates all of the above objectives in a building structure, that is, collection of solar energy, a stable building structure, control over heat loss and heat gain, and regulation of light transmission is extremely desirable. If all of these features can be incorporated into a structural system, without the necessity of additional structural members, which can then be factory assembled there would be a distinct advantage and significant cost savings. Simplicity and design while achieving the multiple results would certainly be an improvement over existing structures where the above discussed desirable apsects, in regard to heat and light, require the use of additional structural elements, in most cases of a complex nature.