Heating, lighting and ventilation systems

A device for controlling the amount of incoming solar radiation entering an enclosed structure and for reducing the amount of interior heat radiation loss from said structure, said device comprising, in combination:

• a first plurality of substantially flat members each substantially reflective to said solar radiation;
• a second plurality of substantially flat members, each substantially transmissive to said solar radiation;
• means for securing said first and second plurality of substantially flat members to one another and to said enclosed structure so that said members of said first plurality are oriented in substantially horizontal parallel planes between adjacent members of said second plurality and members of said second plurality are oriented in substantially vertical parallel planes between adjacent members of said first plurality so as to form a staircase-like construction, and so that said construction is inclined from the top of said construction to the bottom of said construction toward the equator and so that said incoming solar radiation, the direction of which varies according to the altitude and azimuth of the sun, is transmitted at least in part directly through said members of said second plurality when the sun is at average winter altitudes and substantially reflected from said members of said first plurality away from said enclosed structure when the sun is at average summer altitudes;
• and
• a pair of panel assemblies mountable on said enclosed structure so as to be spaced and disposed parallel to one another on the interior and exterior sides of said first and second plurality of said members.