Earth Sheltered Passive Solar house - AGS design concept

 Hi
I am on the way to put together a workable design for earth sheltered
passive solar house - location ~ E23/N43. (slight south slope)
Considerin the AGS concept of Don Stephens - anybody to share
experience building and maintaining similar home with Annualized Geo-
Solar? Will be greatly appreciated.

Particulary not sure how to predict the air flow of the earth- coupled
heating / heat storage/solar chimney system.

Thanks in Advance !
PEACE!

Martin