ZooT got that one right. Many of the early rock bed thermal storage things got mold/fungus infested and were removed. In all of the projects I have planned, I planed on designing where any cooling tubes would have clean-outs and one would be able to clean the tubes if necessary. They would also need to drain any condensation to a sump where it could be dealt with.
One should remember it takes probably 20F 'Delta' before any effective cooling can take place. 40F+ Delta is what AC folks want for effective cooling and humidity control.
The ground temperature at any reasonable depth will be the average temperature for the area. Here, in North Central Texas, it is in the low 70F range at 20' or so. Seldom would it be useful for cooling. Heat is not a problem in a sunny climate.
A clay pipe system here would be a giant petri dish.
Ron
Adventure is just bad planning." -- Roald Amundsen
