Free solar energy using air convection
as an integral part of building design -
This can be applied to any building - all the extra space is useful and the extra cost, so they say, is less than four percent (4%)! Closing and opening vents is only required once every six months.
Passive Solar Heating - WINTER
Air circulated is NOT part of house air system. The house has regular central heating, fire-places and air conditioning, but use is minimized. Any heating used within house goes finally to the roof - then recycles one or more times. The basement can be crawl space or full size with car-parking etc.. The building itself acts as the heat sink. The roof is of course well insulated and air-tight.
Air flow is slow, so space in greenhouse can be used as living space & for plants. Any windows except those of the greenhouse can be opened in any room without changing overall heat use. The building orientation should be SSW-NNE in Northern hemisphere. The North wall air-flow cavities should be at least 12" wide - 14" better. A similar cavity on the East and West walls also helps, but is not vital. Windows in such walls give a very pleasant feel to the house as the walls appear very think.
Passive Solar Cooling - SUMMER -
The basement can have pebbled areas for sprinklers, using latent heat of evaporation cooling to best effect. All house windows should be double glazed. This system also (of course!) works for multi-floor buildings.
The tunnel can be long and end under trees, clearly, the bigger and longer the better. It can also serve as drainage; the air is cooled during transit.
No fans are needed as the hot air rising creates a Venturi effect which pulls air from under roof. The top roof vent assists in pulling cool air up the North wall.
Action is only required twice per year - once to open greenhouse, roof tower and tunnel doors; once to close them.
As the greenhouse roof is open, rain will enter, so the furniture should be outdoors patio style, and the basement needs to drain back to the air tunnel(s).
This idea is so simple, so effective, so pleasant to experience that it's a wonder it is not designed into every building.