GeoThermoMass

For years I have wanted to experiment with an idea of using the earth’s thermo mass capabilities as a means to reduce the heating and cooling demand of your home. So on Memorial Day weekend I decided I would dig up my back yard to experiment with the idea. Went to the hardware store and bought a bunch of pipe and tubing to put in the ground and some grounding rods to work as temperature conduits. I rented a mini excavator to dig a trench. My plan was to dig down about 9 ft deep (the temperature stays mostly constant below 12ft) and then sink grounding rods another 8. I was going to dig a 20 ft ditch and install 15 grounding rods. I estimated this would give me approximately one ton of cooling capacity.

So I put together a manifold of pipes and tubes (see picture). The manifold was to allow me different ways to test my theory. I rented a mini excavator and started digging. First problem, I hit caliche (dirt as hard as rock) at 4 feet and couldn’t go any deeper. The excavator would just scrape the dirt. I decided I had already made the manifold so I may as well put it in at 4 ft. Next I tried to pound the grounding rods with a 25 lb jack hammer. I could only get them about 2 ft into the soil. So I got an auger hooked it to a drill and could get down about two feet that way. So in all I was only able to sink the grounding rods about 4 feet. It was frustrating,

So I made a mess of my back yard. Spent a lot of money and couldn’t get it deep enough. I may still be able to get some information from it. I will have to see if it ends up saving me any money on my cooling bill. At least I tried to do one of my new year’s regulations.