In The Trenches

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So when we drew up the site plans for this house we sketched out a 150 foot line around the property for the geothermal trench. On the computer screen it's this nice tidy straight dashed line that pretty much just goes around the perimeter. Well - as it turns out - trenching 150 feet of dirt 5' wide by 5' deep is a substantially more, uh, brutal process than previously acknowledged on this side of the keyboard.
There is dirt everywhere- or at least, there was dirt everywhere. It's all back in the trenches now. Here's the process:
1. Dig this hole.
2. Lay tubing.
3. Fill hole.
Marty and his crew from Deltatemp did a great job explaining the process (in much more detail than I) and science behind geothermal heating/cooling. Everyone on the crew was ready to help explain, and after a little while I could see why: people driving, walking, biking by all seemed to have a specific curiosity about the geothermal system. Sure, they see the house, it looks neat, and they come in for a closer view, but what they really want to know about is this sign in the front yard that says "this house is cooled by the earth". Even our framer has been fielding geothermal questions for a week or so now. Again, it really speaks to this issue of the common building lexicon: most people don't question a condenser in the back yard, because that's just the way it is. Well, geothermal turns the back yard into a big condenser I guess.

Essentially, during the summer a heatpump absorbs the heat from your house and expels it to the outside air outside through a heatsink (generally a fan blowing through some metal fins). Just like this friendly DINOSAUR:

This is pretty inefficient, mainly because the outside air is already hot, otherwise you wouldn't have the air conditioning on. Also, note that dinosaurs died of bad design.

A geothermal heatpump absorbs the heat from your house and transfers it into the ground via a water loop running about 5' below the surface. The ground temperature at this level is fairly steady between 50-60 degrees. Waterfurnace has some diagrams here. NONE of these diagrams have dinosaurs.

I tried to get some shots of the process of laying and splicing all of the geothermal tubing, check them out in the gallery. We also had some more filming going down- I'll give more details on this when there's more to tell. And someone found a shirt sleeve. And a road.

Actually, I'll go ahead and talk about that a little, because I always hear about these ancient cities found beneath other cities, and my response is typically "did they not notice the other city there or something? How is this possible? Gigantic dirtblizzards?" But right here in the not sooo ancient Near West End of Richmond, Virginia, the big yellow machine is just cold digging up yard, and a couple of feet down hits... a road? The old roads are already a couple feet down.... I guess the term for this would be palimpsest. Now that's a real $0.20 word.

Update: The Augusta Project: The Blog! is in the Richmond Green Drinks newsletter this week! Per the google group site:

"Green Drinks is a simple and unstructured event where people interested in sustainability can get together to network, talk shop, learn something new, share something innovative or maybe even find a job! It's a great time to chat with folks you know or to meet new ones."
The next meeting is August 20th at The Camel, and is a great resource for Richmond. Mark your calendars.

Have a great weekend everyone!

Thanks for reading. We'd love to hear comments, questions or suggestions either in the comments section or you can email us at

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