Vertical Geothermal Earth Tube (Part 1) - Greenhouse Heating/Cooling

Update (January 26, 2017): I made this video in early 2016. Since then I built a new greenhouse (https://youtu.be/OzTf638Xcu0), added a geothermal system to it (https://youtu.be/Qh3-iTJvVR4), and built a compost-based heating system (https://youtu.be/qFGgZfD3G7c).


Most vertical (well) geothermal systems circulate antifreeze down-hole for heat pumps. The "Earth Tube" system is a much simpler approach - blower circulates cold/hot air from the surface to underground, usually via buried plastic tubing. All the earth tubes that I'd seen previously were "horizontal" systems, meaning buried in trenches dug by a backhoe. Here, I drill small holes by hand with a Seymour post-hole auger. I show how such a system can achieve excellent efficiencies - coefficient of performance exceeding 15. In part 2 (https://youtu.be/ghmvI9U1KQI), I describe how I constructed my pilot system

Parts List:

Seymour post-hole auger: http://amzn.to/2jvmABz
4 ft x 1 in black pipe: http://amzn.to/2kz6K6O
1" coupling: http://amzn.to/2k80mWV

25 ft x 4 in flexible drain pipe: http://amzn.to/2kzhCkU
4" drain pipe TEE: http://amzn.to/2k9Efjk
4 in, 100 cfm duct fan: http://amzn.to/2k9CwKS
Foil tape: http://amzn.to/2jvlLZz
Cold Weather thermocube: http://amzn.to/2kzigiu

Outdoor electronic thermometer: http://amzn.to/2kzrC1H
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