Earth Cooling Tubes for Ventilation and Climate Control Part 2

Learn how you can take advantage of the soil’s moderating temperatures for cooling and passive climate control in buildings, workshops, and more. Living Web Farms’ Black Soldier Fly breeding facility uses the energy of the sun and the heat capacity stored in the earth’s subsoil to create a controlled inside climate with minimal or no energy input.
Richard Freudenberger, is our Energy and Resource Coordinator and will explain how the system works, what materials are used, and what factors you need to know before embarking on a project of your own. We’ll look at siting, costs, calculations, limitations, and what does and does not work with real world expectations wen installing your earth cooling tube ventilation system.

[@jestempies]

I haven't seen much in the way of English-language material for this, but here in Poland there's a growing trend of ground/air heat sources for heat pumps. The way they deal with mold and humidity is that you use open air ducts (i.e. a flattened half-pipe) over gravel and sand. This way the air can be conditioned in either direction, and any excess water can drain away - or extra water can be sucked out of the ground if the air is being heated, and since there's no standing water and a lot of air flow you shouldn't have mold issues. The gravel also provides extra surface to exchange heat with. It's usually built under the building to save space and digging effort, as well as isolate from air heat/cold. Due to the climate here it's mostly used for heating, but provides cooling as well.

[@fredericoevandro-veladelibra]

Yeah, why don't just dump the water in the ground?. I look it up in the Polish internet. Interesting models. But How to clean the dust, the usual grime? There is this problem that nowadays everything in the internet is propaganda.

[@stebarg]

Great work👍🏽 Imagine if we all used our minds and resources for building stuff like that❣️😃🙏🏽

[@natashadareling8572]

Thank you, so informative!

[@robanbieber7859]

Excellent information! Part three?

[@gamercat4396]

As Patrick has suggested, I see no problem placing the pipes parallel to the slope on a hill. The degree of slope, towards or away does not matter as long as you place a condensate drain ON THE BOTTOM of the pipe just before the pipe turns upwards to enter the structure or air intake hood (depending on which way the pipe is sloped). A bottom drain is advantageous because it does not require periodic pumping and makes elimination of accumulated dust and debris much simpler that a top down clean out. I would also screen the entrances to the pipes to prevent entrance by animals. I also believe (but have not yet tested this theory), that cross connecting the tubes (every 20 ft or so with acute degree connections oriented in the direction of flow, staggered between parallel pipes), increases efficiency by delaying air movement in some sections and therefore increasing the time available for heat exchange in these sections of pipe which contain slower moving air. To achieve a pulsed effect the air intakes need to face in slightly different directions so that the relative air pressure and dominant flow paths through the interconnected network of pipes are constantly shifting in response to shifts in the prevailing wind directions. To flush the system, simply remove the drain cap and run some water (and dilute disinfectant) through the pipes then connect a suction hose to thoroughly dry it all out.

[@kevinrice5965]

Great concepts here, particularly interested in your ideas about interconnecting the pipes to create a pulse effect and slow air movement down to increase air temp change. If you get this message, I'd love to ask you more about your thoughts about using these pipes in a home. We're getting ready to put an addition onto our house and would like to try to incorporate passive cooling/heating features.

[@skyangel6336]

What does anyone suggest for people living in Humid hot climates for cooling? Just build a house underground Or earth dome above ground and what might be the moisture issues with that?

[@dsawyer8]

You could easily go to a vertical pipe of a larger diameter at your lowest point and use submersible pumps that could be used in the rare case you get condensation build up , which also would make them very easy to pull and service if need be. Lighting could be massively improved for efficiency by using led type low profile. The fans could easily be more efficient by not being blocked by the lighting or other obstacles. The fans pictured are actually low amp but there are far better for the purpose. Your coefficient for the fans would not be changed for the current application by moving them by 6 to 8 inches.

[@SaudaraLink]

What about a gravel bed at the bottom of the pipe under ground, with siphons coming out to siphon out the water. The moisture outside the pipe would help with cooling wouldn't it?

[@JohnGuest45]

This guy needed to do some practical tests prior to installation.The air in my tubes can drop 30F in less than half a second, if i used 192ft tubes, the air would be coasting through almost the full length without getting any cooler.

[@3thicsg]

Tell me more. Is it due to laminar air flow in straight pipe?

[@Iprofessshirk]

Yes, can you tell us the length & diameter of your tubes...what is the temp at the inlet vs the outlet...how deep are your tubes buried?

[@chrisdee3211]

Im no scientist.. but in regards to the water buildup.. could you possibly dig down at the areas that water would gather.. put perforated pipe straight down and surround it with gravel like a french drain? That way the pipe would drain out on its own. I think of septic fields.

[@spnro8699]

Heat problem. Have a high low speed pump that runs slower when the heat is satisfied and to keep fom overheating. Have heating tube loop isolated from hot water source by using a heat exchanger. Hotwater tank side of heat exchange runs on demand, then external heat loop runs high on demand and low speed when satisfied. Then have an addition thermostat that allows low speed to run constantly only when outside temp is below freezing.

[@donwells9494]

Why could you not use perforated leach field pipe to drain out any accumulated water in the tubes?

[@stebarg]

Great idea but you have to be sure the water gets drained out and not the other way around.😃 Must be well above the water table and the surrounding material must be sufficient for drainage also in the raining season. Is there any perfect solution for avoiding water in the tubes?

[@paulkoehl2447]

What type of tempurature controller do you use to turn on and off the fans?

[@stebarg]

7:06 have you calculated/ built the chimney for making it storm prove?

[@Viasun193]

Hey I would like to adapt this system for chicken production in Brazil…..the greatest challenge is energy consumption/ventilation….

[@travishodges5179]

Why not Increase passive efficiency by using waste heat from your biochar to heat the exhaust tube to increase draft flow?

[@oby-1607]

Why were the inlet tubes not nested together in a shaded spot(tree or shed) instead of out in the open? Why were the tubes not introduced to the shipping container through its bottom instead of being exposed out in the open? Why wasn't the shipping container not painted white to reflect heat for the way it is presently it will only absorb heat? Why do you call the heat extraction tube a chimney when it is a cupola? Flow through a pipe is greatest at the center of the pipe and not the walls. If you study flow and turbulence, you will learn this. I hope you weren't paid for this in constructing or advisement of theory.

[@somedude-lc5dy]

not my setup, but if you watch the other video: 1) they said they wanted to shade them with trees but just didn't get to it. 2) they have radiant floor heating, so it had to come in through the wall somewhere. then, they had the stacks of drainage and habitat. nowhere else to really put the pipes without sacrificing floor area. 3) not sure, but maybe it does not get much direct sun. 4) probably because everyone knows the concept of a chimney, but not everyone knows cupolas. 5) he was saying that the heat transfer is greater at the edges "perimeter of the inside of the pipe is what's catching the coolness and if you", not the fluid flow.

[@ondrejv416]

Is there any way to clean the tubes? (bacteria, mold)

[@stebarg]

Good question. We installed a similar system 1994 for an air/air heat pump for our home. It’s for cooling in summer and preheating in winter. Besides a screen and a filter, there’s nothing we’ve done for cleaning, and we have had no issues since then. I guess there must be some (probably expensive) robots which are able to inspect and clean those pipes. Maybe it’s sufficient if you check the incoming air for mold etc. first and if the air is bad then take further action like renting those tiny robots..😃

[@dragonstonegemironworkscra4740]

@@stebarg , is your system closed loop or open loop? I've done se preliminary searches for the air to air system with no results. Only the liquid filed system. Thank you for any insight you may choose to share. Its pretty much dry climate here in west Texas and it routinely stays above 80⁰ up to 115⁰f

[@rab9212]

You can run a UV-LED light strip down the tube to sterilize it as needed.

[@Aquatic_Boys]

@@stebarg yeah but for your air to air heat pump these tubes are on the outside part of your system. The air from the tubes never comes in the house but the heat is transferred by the heatpump to the in house airflow.