from Ekopedia
This solar air conditioner can be made with low cost materials and a little labor. It has no moving parts. The sunnier the day, the better the efficiency.
The principle
A black painted, 150 mm diameter metal tube stands out of the roof, 6 to 8 meters high; the air inside gets hot and rises creating an airflow which draws cool air into the building, possibly through an Evaporative cooler W.
Making it
In order to have the air swirling the right direction, you also need a slotted cylinder 200-300 mm in diameter, welded to the bottom of the black tube. The slots must be vertical and have their rims bent inwards the right direction, i.e. counterclockwise in the northern hemisphere.
Alternative design idea
In the Hexayurt, the aspiration device could be used alone, with a wet cloth fitted on an air inlet near the ground, using the evaporation to cool and moisten the incoming air.
External link
The original article from Ekopedia, in French language but with the drawings [1]