The South window wall (details at left) is the piece of architecture that feeds the solar system, both the passive (immediate) and the active (stored). The storage medium is a concrete sub-slab labyrinth (to be discussed later.) The window wall has an outer layer of insulating glass and an inner layer of single glass. On the bottom 2 windows, on each side, the inner layer is replaced by an insulated collector plate. Air is drawn from the sides of the center top window into this cavity (right and left) through a dust filter, down through a back draft damper into the storage labyrinth. The fan is located at the other end of the labyrinth on the north side of the room; this de stratifies the air temperature in the space, both vertically and horizontally .
All the windows have a layer of black anodized aluminum screen on the outer edge of the cavity to absorb a portion of the sunlight; so that the air becomes progressively hotter as it moves downward, and is boosted at the end of the run by the collector plates. An expected air temperature of 120 degrees F is adequate for this system. The strategy is that in winter some of the light passes through and heats the space directly, and some is removed and stored for nighttime or overcast weather. The choice of screens for mini-absorber plates in the windows was based on the common experience that people have of looking through screens and mentally "reading them out".
The collector plates at the bottom are made of punched aluminum sheets,with a selective surface paint, canted to force the air to pass through them, the turbulence transferring heat from the aluminum into the airstream.
The masonry in the interior space between the glass layers is painted a dark magenta to absorb any intercepted light. While black would be optimal, the chosen color has a greater visual sense of "heat". Also each layer has color differentiation to emphasize its existence. The window becomes something to look at, as well as to look through.

Additional light and heat is introduced by a south-facing monitor centered on the N/S axis extending the full width of the building. Light entering south-facing glass at low angles in winter is reflected off a canted mirror downward through a horizontal layer of glass. In summer the sun angle is too high, and only a thin sliver of direct sunlight can enter, although sky-dome light helps to even the visible light at the center of the space. This feature is highly articulated, and has proven to be an intriguing object for visitors.

The sub-slab mass bed is constructed with concrete bricks as walls covered with 18 inch square by 2 inch thick recycled concrete pavers. These pieces were assembled with landscape adhesive (some no VOC types are now available, but challenging to find off the shelf.) A thin topping coat was used to level and connect the pavers. Air is drawn down the south wall and on each side runs down to the north, returns to the south, then back to the north where it vents back into the room. Some of the heat is transferred to the bed and some to the north end of the space at the floor level. This destratifies the heat both vertically and laterally in the space, while storing a majority of the heat for nighttime when it slowly radiates upward through the slab. In summer the fan can be run at night with the four windows open to use the mass as a cooling battery for the space. An adjustable thermostatic sensor operates the fan, that also contains a rheostat for further adjustment.