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Can you use the Solar heater with earth tube, or would the heat coming through the tube go into the ground? Answered

Have been browsing the different sites looking for a good way to passively heat and cool my place, for winter times heating primarily.  Was looking at the following instructable https://www.instructables.com/id/Solar-Heater/ when the above thought hit me.  If I didn't want to cut into my wall to do the solor heater, is it possible to run it through earth tubes to provide the heating.  Didn't know if you would have to much heat displacement coming through the tube going into the earth.  Airflow is to be ran by a simple computer fan on low powered solar panel/battery



If you look on the Mother Earth News website, there are many DIY projects with solar heaters.  If you don't want to cut into your house, there are smaller units that you can build that fit into a window.

I just think that you'd waste a lot of your energy trying to move hot air through the ground.


8 years ago

The area that I live in is Northern Louisiana,  haven't checked heat of ground at the depth you would put the earth tube.  Have considered using a solar water heater since I have very nice southern face during the window months.  If the sun is out, it's hitting.  Have gotten several discarded water heaters with a tank intact, work on a conversion for those now. 
Digging isn't much of a hassle for me because of access to a mini x,  will have to take some reading at around 2-3 ft deep to see what the temp is.
Thanks for input

And/or how much insulation are you willing to put between the tubes and the ground? You're mostly going to lose heat to conductance rather than radiation, so if you could -- for example -- wrap the pipe in fiberglass or foam, then run that insulated pipe through an outer pipe to keep water from getting to it (water can soak up a heck of a lot of heat)... well, it shouldn't be any worse than running the pipe through an unheated basement. (A very narrow basement.)

Related: how deep are you willing to dig? If you go down far enough, ground temperature essentially becomes the yearly average temperature for your reason, since it takes so long for heat to diffuse either in or out. That's why water mains and wells and such don't freeze. So a deeper pipe might need less insulation than one closer to the surface.

I suspect this would be enough work to not be worth the effort.

The thought of doing a solar water heater rather an solar air heater sounds more practical. Or use water to extract the heat and run it through a radiator inside the house to heat air.

(A friend of mine has a professionally installed solar water heater on his roof. He's less than delighted with it.)

That;s what it comes down to, how hot is your ground at the depth you can put the tubes ?

How warm is your ground as compared to the inside of your house?
You could make a solar water heater, then you'd only have small holes to make in the wall for the pipes?
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