Earth Tubes | Page 3 | Construction and DIY projects | Forums

Can you double up on the earth tubes? Not two single pass units but cut a wide enough trench for a U? That might save on trenching costs. provided that the two tubes aren't so close that they affect one another. You could also paint the inlet black and set it up under a canopy so that in the summer it was shaded and in the winter it would be hit by direct sunlight. This may or may not be of assistance. I was just thinking that in winter it would essentially be a solar collector if you made it long enough. Don't forget your T at the inlet for the drain. This allows you to avoid taking it downhill. I drew it upside down so don't pay attention to that detail.

Also, this is the basic schematic that I came up with a while back to be used for my house. It assumes that the earth tube calculations might be a little bit off so you've got an auxiliary system for backup. I would probably revise it to include an HRV for the outgoing air but this was assuming that my house would not be sufficiently airtight as Speed mentioned.

Gravel, are you doing septic? Theoretically you could piggy back and run your earth tubes in the same trenches as your leech field. The soil would be more moist and therefore more thermally conductive. You'd just want to make sure that your tube is well sealed.