GeoThermal Greenhouse Build | Part 2

This is the second episode in a series of videos on building the geothermal greenhouse. This is the one where it all happens! :-)
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[@KhangStarr]

Awesome project, Chris! Can't wait to see the next part. Love the part when you son joined.

[@ChristopherBrandsdal]

Next part on sunday! :-)

[@mark109s]

Christopher, Great video thanks for explaining step by step. , this has helped very much. Thanks . Good luck with the Green house.

[@lenaalff5640]

Thanks for doing this Step by Step.😊

[@Dillweed39]

Did anyone else catch Chris going for a ride in the bucket at 11:11?

[@PatricesProjects]

Exciting stuff.. You're going to be chomping at the bit towards the end of winter wanting to get going on the greenhouse.

[@ChristopherBrandsdal]

Haha, I am allready! :-D

[@keigan9006]

Love these videos of your building this geothermal green house - in Norway, no less. I live in Minnesota, in the US, and these videos have really inspired me to trying to build a unit just like yours for here at my property. Thanks, I am moving on to watch the rest of the videos.

[@ChristopherBrandsdal]

Glad you like them!

[@maxsmycology4141]

From MN as well, curious if you ever went through with this.Thinking about this myself.

[@MistyMightBeManicShaklefor7416]

Looks good! Can't wait to see the progression and your bountiful harvests in the future. The doggie running thru the work site was adorable in fast forward :-)

[@anthonytran9191]

Very neat bro! Good luck with the build.

[@bigh650]

cool - hope it goes well this winter - all the best

[@markbrennan8392]

Right on Chris, great project and can't wait till spring ;-) Hope things are going good otherwise too and going to start up your "Voodoo Garden" again? I bought some of the large lights like Ray has and hoping to grow a pepper or tomato or something. Take care.

[@sandhollowhomestead6972]

Happy you were able to do this. A brighter future 😉

[@ChristopherBrandsdal]

Thanks!

[@MJ-iy4fb]

great music!! nice job on the video, i hope to see how this works.

[@iphoneblack1]

I really like you videos. Nice job

[@philroll6008]

Pretty cool

[@chriswhite6882]

this video is perfect for my situation

[@AllanBryant]

Great stuff mate, looking to do just the same with Aquaponics here in Melbourne Australia. Good to see the work needed in action, builds confidence :)

[@dinokpir]

Consider consulting an engineer for airflow flow efficiency. See a comment thread started by johnguest45 in this video.

[@rebecca2565]

Very interested to hear how you got on!

[@jaymanikkam4521]

Great video and hope you post an update on how its doing now. Any problems with water entering inside the tubing? Also, What kind of temperature probe did you use for the underground ?

[@danielbeltranvaras8950]

Hi Christopher, really nice proyect!! I found your aproach very interesting and I was wondering... the baterry seems perfect for storing summer days heat to use it in the nigth, but in winter, as it is insulated from the sun it will be harder to actually transfer some heat to the gravel to use it in the day or night, I was thinking maybe you could have some part of the battery below the greenhouse and other part below the sun (soil in the middle). I'm really eager to see your results, congratulations!

[@yes12337]

Wow, you're actually living the dream of most gardeners. This is awesome!

[@theusconstitution1776]

❤️🇺🇸YOUR DAD RUNS THAT EXCAVATOR LIKE ITS PART OF HIM❤️🇺🇸 can’t wait to watch part three! My difficulty here is you dig down 4 feet and you have flat ledge at 4 feet and I think I’m going to dig down to it and put a temperature probe there and watch it this winter because I think the ledge itself will hold or deliver more heat and the rock? I wonder if you clean off the ledge in a similar area put the tubing down and anchor it and pour a concrete slab directly on top of the ledge and your solid piping, would that then become a much better heat sink😳. Hmmmmmm I wonder???

[@ChristopherBrandsdal]

Many good questions there! Not sure. You should definitly dig down and thest the temperature this winter! Awesome idea!

[@1Ascanius]

Great project I built one myself and I’m nit sure as to your location but a small EFFICIENT wood boiler would be a smart backup especially if the temp drops below -10c. Peace

[@ChristopherBrandsdal]

I am considering that. Just have to get it up and running and take it from there.

[@harrymills2770]

rocket-stove mass heater so you only need to run the thing an hour or so to keep the chill off all night, without smoke/stink. You pump ALL the heat from the fire into an earth mass and it gives it back over hours.

[@cascadervsolarsolutions]

Just curious, why did you not run your temp communication before you started to backfill?

[@AliMohamadChannel]

good work , gravel does not retain heat better than clay , having air pockets makes it worse as it insulates you want dirt to stick to your pipes to conduct good . also heat renetion does not stay for a whole season yes you can retain daytime heat for release at night but not summer heat for release at winter

[@tonybanner7599]

That’s some large boulders you found

[@hydrologicdesigns]

excellent job. which sensors did you end up using?

[@jimviau327]

Great build! Thanks for sharing. When are you posting the result ?

[@ChristopherBrandsdal]

More to come when the snow melts! :-)

[@blauschuh]

i bet loose gravel has a horrible thermal conductivity...

[@jonattanpichardo8655]

hey christopher, hope it works out great. would really like to see you grow many types of plants, hopefully this greenhouse will allow that. also i won the giveaway you did, but never got the seed. i just thought it got lost or something. just wanted to inform you.

[@bionicerkin]

Hello. Hope you have been lucky with your system. I've been researching earth batteries here on KZbin and other web resources and one thing I learned is that the optimal pipe length for the small diameter (4 inch) branches is 25 to 35 feet where each pipe connect to a larger diameter (8 inch) perforated tube at both sides of the dig. This length is said to be best for getting rid of the humidity in the air into the soil for cooling the hot and humid greenhouse air. In the winter, cold and dry air in the greenhouse is humudified by the water in the soil, and when water becomes vapor, it also carries the heat it gained from the soil into the greenhouse. This is actuallythe main contributor to both heating and cooling potential of earth batteries (phase changes of the water) and like I said, the above length of each segment was found to be optimal for this purpose. Your tube length is very long if this is actually correct and I learned from some Canadian installer, a mechanical engineer indeed, who said he has been designing these systems for years (his KZbin channel is Verge permaculture), for commercial customers too.

[@JohnGuest45]

When the cold. dry air picks up moisture it takes sensible energy from the mass to effect the phase change. The sensible energy is converted into latent form which doesnt affect the temperature of the air just the RH%.

[@studdruppo]

Awesome video. So, is it better to dig deeper and use more rock as a heat sink?

[@mio.giardino]

I love how you're showing this build. As I watched it was odd to me that if you were concerned about water settling I the pipe then why not drop in a pit where you can drop a line down to pump it out?

[@ChristopherBrandsdal]

Hi, Mio! I actually will put down such a pupe on the next step come springtime. :-)

[@berendlensvanrijn386]

do you also have some guidelines for length and diameter of pipe when they are filled with water? i live in dubai and aim to col down the pool water by 5-10 degrees by running pipes under ground.

[@edwardschneider2716]

Great video and information. I didn't read all of the comments but are you adding a perforated drain time near the white building? It's my thought drainage along that side may be challenging. Just a thought. I'm sure you have it figured out.

[@ChristopherBrandsdal]

It actually works very well! Running for two years now.

[@badluckwitcarpet]

I may have missed it, but what size pipe are you using here?

[@lazywhale7364]

As pointed out by others, each run should be supplied with air through a header - you will not be able to pump enough air through one long run. Sadly, you see the same problem with the solar thermal people where they use one long run of copper tubing. You have to keep the air and/or water velocities relatively low to avoid large pressure drops which in tern limit the efficiency of the fans or pumps.

[@JohnGuest45]

The tube layout will force the fan into providing less air which rquates to less heat being moved. Remove the fan from the system where it can produce its maximum flow rate and Measure the current draw.Place the fan back into the system and check the current draw again.The lower the current, the less air the fan is producing. In Christopher`s layout its not easy to draw a definitive conclusion from this test because the air can take a shorter path through the gravel to reach the outlet Air will always take the path of least resistance. If you see high current draw (high fan air flow rates) on the serpentine tube layout you can be sure the air is bypassing a lot of the tubing because the resistance in that type of layout will be very high and you would expect to see less airflow highlighted by lower fan current draw. Sinking temperature sensors a some distance from the inlet/outlet tubes will tell you if the air is getting there or not. Ideally, you want to be seeing a temperature change in the mass over the entire length of tube. If you see a change in the first few feet near the inlet and no change further away, you can be sure only a percentage of the tube is actively exchanging heat.

[@k.r.6800]

I was wondering if it would be better to install one small blower on each tube instead of having one bigger blower blowing air on all the tubes at the same time. The idea is to have continuous airflow in case one blower stops functionning and more flexibility for air distribution. We can switch on and off one or more blowers if needed to get the desirable airflow.

[@AirandEnergy]

Maybe I'm missing something but don't you worry about radon gas creeping in through the soil and the tubes picking it up?

[@ATBrickscom]

A project like this is begging for a rocket stove inclusion :-) nice job Chris!

[@ChristopherBrandsdal]

Haha! Don't think I haven't thought about that.

[@harrymills2770]

I'm no expert in thermodynamics, but I think nesting the pipes so close together probably reduces the amount of heat exchange you're getting, significantly. The temperature change you're obtaining is from the gravel around the pipe, so except for the outermost pipes, you're not giving the gravel as much of a chance to rebound in temperature from the heat/cool you're extracting. I think the idea is long, narrow trenches, rather than one big pit. I could be wrong. I just think you're overestimating the amount of heat conduction underground.

[@guiltfreehotwater4354]

So Good! hw did it work?

[@kieranhanrahan2883]

the length of pipe - would shorter sections all terminating in the same place reduce the size of the air pump required to move the heated air in and out of the pipe system? Would 5 x 20 metres be better than 1 x 100 metres? Thanks

[@andreyzelenin8508]

и в каких регионах это ?если север,то понятно будет эффект а стоит ли городить огород с такими сверлениями в Крыму?

[@risalatnazir4345]

HI,I would like to know the pipe details like type of pipe used,its diameter,details the insulation blocks you are using in the sides and also the black sheet which you are using in between the layers of pipes and soil. Thanks

[@adddad9779]

This landscaping tubing has a bad wrap for runnng drains in our area of the world since it tends to collapse. Being so deep, I have concerns it will collapse and not work. A consideration would be schedule 40 PVC with drilled holes for drainage... Just my $0.02 but inflation blows.... Thank you for your content sir, as I am close to doing the same thing. I liked your use of lits of rock!

[@ChristopherBrandsdal]

Thank you so much, Jason! I'm crossing my fingers. Keep me posted on your build!

[@Luckykhan1993]

hey great job u did now tell me the resultant cool air or a data / I mean outside temp. and inside temp is 40degree Celcius outside then how much inside will be. its just example u tell me your result.

[@djw6850]

Great stuff, can't wait for the follow up in the spring! I'll also be curious to know what your sensors are telling you throughout the winter. Btw, as a programmer, are you interested in what's happening in the crypto/DLT space? My gut tells me that internet of things is bigger than most people comprehend and it strikes me that DLT and iot are a match made in heaven. I've been investing in any iot related blockchain that I can find...IOTA, WTC, DATA Streamr, INT etc with hope that some of these may be the next Apple/Google etc.

[@ChristopherBrandsdal]

Have not been able to test temps yet. We have close to 4(!) feets of snow here now! Yes, I am very much into crypto. I both hold and mine. :-)

[@bethduffey247]

This is so interesting and fun to watch. I love your “can give it a try” and “just experimenting” attitudes, but know you must have put a few hours into researching as well! I look forward to seeing your results. May the Force be with you, too! You must sometimes have some sore muscles!

[@ChristopherBrandsdal]

Thanks, Beth! An yes I do get sore somtimes haha!

[@JohnSmith-gm3qm]

Would running water in the pipe (if the pipes had no holes) be better

[@paisley436]

any updates? Many times in this (very helpful) video you said things like, "I think..." "I believe..." "I hope..." How did it turn out?

[@sherrypreston5660]

How is your geothermal heating and cooling system working? I put one in almost the same as you. Mine filled with water and I can't get anything all the way through the tubes to pump it out. You have that problem at all?

[@ChristopherBrandsdal]

I am not finished With the build yet. I ended up digging a drainage pipe all the way out of the property to avoid water filling up the pipes. Will show more in my next video the coming weeks.

[@k.r.6800]

I see a mistake here. Not enough inlet and outlet. You need at least 5 air entry and 5 air exits to get enough air flow. In your case you have only two entries

[@glens51]

What type (and how many) temperature sensors did you use? Also, did you connect them to a computer data loger ?

[@ChristopherBrandsdal]

I will switch out everything this year to my own made microcontrollers, and use a variety of sensors. I will make a video on the setup once the greenhouse gets going. :-)

[@colehatchard6492]

Hey! Just wondering where you're located?

[@KAYAPOGAN]

Thnx 4sharing yr idea. (+) Criticism:- Before Gravel should lay geotextile THEN gravel on top, AFTER Geotextile covering gravel including laterally encapsulating it because water-silt-sand will block pipes after few years. Last where water was rising cut down a trench draining water downwards the hill naturally keeping warm your gravel. Cheers and tnx!

[@ChristopherBrandsdal]

Thanks for the input. :-)

[@EclipseVisualSystems]

You should check out the Thermal Greenhouse build on HowToFarmAndGarden.com. They used 6" perforated pipe with large rock around it. A bit different approach but the results are amazing.

[@danfaber921]

I am wandering if you can use this system with a green house that I already have by excavating next to the green house and running you heat transfer tubes to the inside of the existing greenhouse

[@ChristopherBrandsdal]

Should work, but might not be as effective.

[@chrischung2365]

Did you build the greenhouse? DId it work?

[@MrMolledm]

Soil required compaction for slope stability Keep an eye out for structure movement post construction

[@ChristopherBrandsdal]

Has not been a problem at all. Still fine after 2+ years. :-)

[@johnnyb8629]

I'm toying with the idea of using a thermal mass battery such like this but not for green house but for bringing up air for an air to air heat pump for housing. I'm also thinking of using the air in an economizer for living space air. Looking at the amount of ground water Im thinking that using this for what I'm thinking that would need to be addressed as that ground water would make the air unsuitable for an economizer. Perhaps using sealed HDPE pipe and welding together a grid using vertical headers at each end where you could set a sump pump would mitigate this. Does anyone have any engineering math to calculate out a delta T and pipe length ?

[@exequielvarela4960]

hey! Nice video, please upload the next step. By the way, i don't get why you put some plastic cover over the gravel, the main source of energy in the soil comes from the solar radiation, so you shouldn't put any extra material capable of preventing the heat transfer in the soil from the surface to your circulation pipes. Everything considered it's a nice video, it lacks alcohol, sex and rock and roll, but it is a nice video.

[@robjohnson8861]

From what I read, the pipes need to be farther apart but they were using earth.

[@carolynbarnesjdphd]

How exactly do you monitor the heat? Do you use the IoT and an arduino or how exactly and do you know how to program for that measurement and regulation of heat flow and temperature?

[@JohnGuest45]

The best option to control the system fan is to use a combination of standard thermostat and differential thermostat in conjunction with a fan speed controller. Having a multitude of air, soil temp and RH sensors/ probes both inside and outside the greenhouse is great for collecting, tracking and comparing heatflow data.

[@ChristopherBrandsdal]

You are correct. IoT! I will do a program on this come spring when I set it up. Will share everything.

[@jarnar08]

how deep is the frost line at your place? In Germany we say it's at 60-80cm... the idea of geothermal is to use the heat/cooling from the ground so insulation below the frost line doesn't make much sense as you can't use the thermal mass of the surrounding earth in that case (sometimes insulating flat shortly below ground level is even better than vertically)

[@JohnGuest45]

The idea is to store the excess heat from the greenhouse in the ground. The heat comes from the sun, not the earths core ;) If Chris`s greenhouse maintains 80F 70% RH on a sunny winters day as he runs all the greenhouse air underground 10x in 1 hour and it exits the tubing at 50F 70% RH he will move almost 80,000 btu (23.2kw) from the greenhouse into the mass in that hour. The main problem is Chris wont be able to capitalise on it as he cant move close to that volume of air through those two 328ft heavily corrugated tubes that were not designed to carry air (drainage). If that wasnt challenging enough there are 11 hairpin bends in each tube. Chris should bill LDS for the excavation and reinstallation costs as thats the only way to fix it.

[@ChristopherBrandsdal]

The frost line here is close to a meter.

[@markroeder2491]

I think Jarnar is talking about a "Swedish Skirt" type of insulative system. This lies horizontally on the surface and creates a 'bubble' at depth below it. Since you already have vertical insulation in place, you are fine.

[@jarnar08]

Yeah, it wouldn't make sense to rip out the existing insulation. I just wanted to say that insulating below the frost line (1m in Chris' case) is not really needed for his application and the flat one might be a possibility for future projects or other people wanting to replicate it (easier than digging very deep)... maybe for the other half of the greenhouse?

[@jcb570]

please do a update on this video. I like to see how you set up the fans. also whats the ground temp.. I want to try somthing like this myself. thank you..

[@ChristopherBrandsdal]

Updates will be coming soon.

[@jumboarg7357]

Why don't you use metal pipes under the ground for better heat conductivity?

[@dennisbuckleyable]

I learned my Geothermal air system from a very competent citrius grower in Wisconsin who for years no buddy would believe was growing there all year round. I guess you are going to pay a small fortune heating the ground under your greenhouse and have a massive amount of loss, where I use the ground thermal to stabilize the temperature in my greenhouse at about 65 degs. with 1 six vdc fan, 1 solar panel, and 2 12vdc batteries on a small charge control.

[@TheRebelmanone]

Stuff with more mass holds temperature better, water has more mass than air so moist dirt seems like it will be more temperature stable than dry dirt because it is more mass. But it won't matter anyway either way because if you dug down below your freeze line in your area, then the earth itself keeps its temperature stable down there regardless moist or dry. That is the whole purpose of using geothermo style, taking advantage of the stable temperature under the freeze line, summer or winter. But i figure you must be talking about temperature transmission, or temperature conduction between the earth and the pipes, because i know you must know what you are doing. And i agree if that is what you meant, to get better temperature transmission from the earth to your pipes you used large gravel with big air gaps so in essence you are extending your pipes into like a tiny vein system which can extract more temperature. Genius thinking. I didn't catch the reason you used perforated pipes unless my figuring was right above, maybe i watch again later i missed some stuff.

[@rebecca2565]

Nice vid - how’s it going with the geo thermal greenhouse? Thanks :)

[@ChristopherBrandsdal]

Going great! The house is now set up. New video yesterday and next sunday. :-)

[@rebecca2565]

Christopher Brandsdal thanks - I am researching a big build of polycarbonate greenhouse and may not be able to get it together to do the geo thermal thing but I want to take advantage of hugkeculture beds and get some deep paths in the greenhouse so that we get some heat coming up from them... any experience with these things for optimising natural heat and extending the seasons

[@ChristopherBrandsdal]

Great idea! No, I have no experience growing that way...

[@markroeder2491]

A red flag for storing the heat in the soil mass below your greenhouse was the high water table or excessive moisture in your system. I have heard that the water will disperse the stored heat away very quickly and not allow you to use the surrounding soil as a thermal storage battery. You should still have no problem using the thermal mass above the heat tubes.A quick fix to your dilemma might be to cut your tube length down and increasing the number of supply lines. A little shovel work now might pay off handsomely. Air resistance is the major flaw with LDS's design. If you plan using a movable insulation cover at night many of your concerns will be taken care of. Just having an insulated hole in the ground should keep you above 45F (7.22C). Good luck and you're doing a good job!

[@ChristopherBrandsdal]

Thanks for the input!

[@jeremydoesitgresham9530]

Mars Rover yeah your so wonderful your advice too bring a shovel Mr red flag

[@agustasister5624]

Will those pipes hold the weight of that soil??

[@ChristopherBrandsdal]

Yes they will. These pipes are intended to be in the ground.

[@markgil400]

Any update? Is it working?

[@BushImports]

Did it work well for you?

[@bhatkrishnakishor]

Check his playlist, it has one year update video.

[@larryames8831]

Thanks for your video. And I wish you success. I assume by now you are up and operating. I am concerned about mold growth in the buried ducting. How would mold not grow in the buried ducting? You are not going to any usable air volume through 300 linear feet of 6" corrugated plastic pipe, By now you may realize you should have installed 14 to 18-inch headers. I have yet to build, but my scheme involves supply and return wells and heat exchangers. Take Care. Mid -Atlantic US.

[@ChristopherBrandsdal]

I will make a video before winter with my thoughts on my setup and how it has worked this summer. :-)

[@larryames8831]

@@ChristopherBrandsdal I reviewed more of your videos. You built a really nice greenhouse. You may consider getting your airflow volume up to 6 - 8 room changes per hour to attempt to hold your humidity down. The amount of air you move is most important as long as your ground sink is lower than your leaving air temperature if your goal is cooling Lastly did you consider the entire interior of the greenhouse volume. As mentioned there is flowing water under the heat sink....the sink is going to be losing heat quickly. Good Evening.

[@ehcit4548]

Does it work? Wanting to do this for my greenhouse

[@ChristopherBrandsdal]

We will see this summer! I have a few new ideas I will test this spring.

[@angusm9419]

Hi great video! What country are you in?

[@ChristopherBrandsdal]

Howdy! Norway here. :-)

[@angusm9419]

@@ChristopherBrandsdal Looks like beautiful country! Thanks for responding!

[@kansaIainen]

What is the reason to use perforated pipes?

[@ChristopherBrandsdal]

I want to take advantage of the air running free into the gravel.

[@ChristopherBrandsdal]

And also for condensation drainage.

[@mattwoody1089]

You probably have radon gas in high concentrations use a filter system

[@Everclearish]

How did it go? Good ,Bad etc.?

[@ChristopherBrandsdal]

Not finished yet.

[@FelonyVideos]

Unless I missed something, this is not going to work at all. The air will simply take the shortest path from inlet to exhaust through the rock, and the majority of the thermal mass gets abandoned.

[@JohnGuest45]

I`m sorry to see you putting so much time and effort into an installation that wont work very well, if at all ;( I would not recommend anyone copy the LDS installation as it has major flaws. The individual tubes are just too long and, when combined with the serpentine layout, creates a massive resistance to airflow, which is the exact opposite of what is required. The formula for the total tubing is not related to the greenhouse air volume, its related to the mass. The greenhouse air volume is used to calculate the required airflow. Once you have the tubing and airflow information, you can design the most efficient tubing layout and specify the correct fan for the task. Now you have backfilled the hole your options are limited to two, leave it knowing that it wont work or dig it back up. I hate to see folks being put in this terrible position simply because they trusted incorrect information. Judging by the numbers you gave in the video, your greenhouse volume will be around 5577ft3 (158m3). The design airflow based on running the entire greenhouse air volume underground 20x per hour is 1860cfm (3160 m3/hr). The tubing layout you have installed will limit you to around 150cfm (250m3/hr) assuming the fan can handle 2.6 in wc (650 Pascal) at that flowrate. The heating/cooling performance will not be close to expected as the greenhouse air volume will only be run underground 1.6x per hour.

[@lecsu131]

Where did you come up with those numbers? Why 20x/h? How did you calculate the flowrate deficit due to the pipe layout? I'm not sarcastic - I REALLY want to know because I plan on doing this in the spring.

[@JohnGuest45]

Hi Alex I installed mine back in 2009 and can tell you there`s more to these systems than meets the eye, Common sense should tell you that most of the ones on you tube are not well designed. Run some of LDS`s or Chris`s numbers past a hvac engineer and he`ll probably laugh, you wont find 100m runs of 4" corrugated ducting in any normal installation because the idea is to move air efficiently, not create as much resistance as possible ;). I`d recommend doing research on airflow and losses in duct systems. Having some basic knowledge on soil heat capacity, conductivity and diffusivity will help you to understand how the heat transfers to and moves in the ground. Likewise, you can use a psychrometric chart to figure out the amount of heat and water vapour in your greenhouse air volume. Armed with these things you can calculate how much heat you have and what it takes to move it from A to B efficiently. In Chris and LDS case, the restrictions inposed by the design itself will be the limiting factor. In the summer, they wont be able to move enough air to keep pace with the incoming solar gain and the greenhouse will overheat. Fitting a more powerful fan wont help as losses increase with flowrate and, the harder a fan has to work, the more its going to cost in electrical power. I purposefully sealed my greenhouse on a hot, sunny day and managed to heat it to 140F. With it still sealed and in full sun, it took the system a shade over 12 minutes to drop it to 68F. In normal circumstances it wouldnt get as hot or need to be cooled down so fast, but its capable of doing it. In normal operation, efficiency is the key. Its cheaper to run the fan at a constant steady flowrate that keeps pace with the incoming gains than to run it flat out intermittantly. Whatever you do, dont bury any tubing until the design works on paper..it will save you a lot of unnecessary digging.

[@bobandsonambrownlee5150]

Considering most of the systems posted on youtube are not designed well, would you be willing to share your expertise and post a diy video, or pass on more specific information on how to build an efficient system?

[@JohnGuest45]

Hi Bob Specifics are not easy as some folks might need a system that is biased to cooling (hot climate) or biased to heating (cold climate). When an engineer designs heating, cooling or ventilation system he doesnt just guess and hope it works ;) . Most systems on you tube are copies of copies of flawed systems. Where formulas or recommendations are given, you should always ask yourself if it makes sense. For example, LDS advocates the total tubing should be 10% of the greenhouse air volume, if you ask him to explain the reasoning behind the formula he cant provide an answer. The air is simply the transport medium, it bears no relationship to the total tubing length. The air volume is used to calculate the fan cfm. Consider the tubing is installed in the ground below the greenhouse. The amount of mass in contact with the tubing is responsible for heat transfer. If you bury all the tubing in a single layer 8ft deep. the mass in proximity of the tubes will heat up (or cool down) rapidly. The ground above and below the tubing layer will gain (or lose) heat via conduction which is much slower than for the tubing layer (google for soil conductivity, diffusivity to get an idea of how fast heat moves through the ground) The important thing to remember is the temperature differential drives the heat transfer process. The tubing should be evenly distributed throughout the mass both horizontally and vertically so the entire mass is utilised efficiently. Consider one of Chris`s 100m serpentine tube runs in terms of tube surface area in contact with the ground. Mow consider the same tube cut into 10x 10m or 20x 5m tubes which have exactly the same surface area but without the massive losses which set the limit on the amount of air he can run through them. Folks find it hard to believe how fast heat can be transfered, hence they go for long tubes, thinking the longer the air spends inside the tube the better it is. In reality. its the amount of time the entire greenhouse air volume spends underground. Dropping 30F off the air in half a second is easily achievable, if the air spends 12 seconds in the tube, it`ll be coasting for 11.5 seconds without transferring anymore heat. Its not easy to cover everything in a single post but hopefully it provides some insight.

[@danw3113]

John, good information. But do you have recommendations on where we can find specific info to build our own...that actually works. I'd like to build my own and can't afford engineers or other specialists, so I've been going purely off of youtube videos myself. Surely there is a good book that covers specifically building your own geothermal greenhouse. No?

[@Xcerptshow]

Why are you insulating dirt????

[@TheBowersj]

I don't understand, why not just build the greenhouse in the hole?

[@georgemckenzie2525]

Radon concerns with that crushed aggregate 1970s Vermont all over again

[@johngliha451]

cubic feet / 10 = linear meters of pipe needed? Why use feet and meters for this? What about cubic meters / 10 = linear meters?

[@JohnGuest45]

I dont recommend you use that formula, its not correct ;)

[@johnmirbach2338]

😁👌🖖✌👍😎

[@vanjagudac382]

vertical hole diging is cheaper!

[@iivanov22]

may be it depends what soil do you deal with

[@runerafell4480]

Skjedd noe nytt i prosjektet her 😎?

[@ChristopherBrandsdal]

Næ, prosjektet er nedsnødd enn så lenge. Men jeg må si det kribler i fingrene etter å fortsette!

[@user-hc8es6cu4t]

Беред сусашедшего😂

[@iivanov22]

Covering pipes with drainage material is very stupid idea man, this way there is much air around the pipes, and the air is good termoisolator, so the heat exchange is lower. The best you could do is to make a bed of clay under the pipe to hold water and make the soil around pipes denser this way you will improve heat exchnge between the air in pipes in the soil.

[@danilcarl1947]

Гляньте vasha-teplitsa.ru/karkas/solnechnyj-vegetarij-svoimi-rukami.html

[@east928]

You have beautiful eyes.

[@ChristopherBrandsdal]

Thanks! I will give credit to my parents. :-)

[@maryhornbostel6959]

This is not the way to do it. Check out Retire growing oranges in Nebraska. He knows what he is doing.

[@ChristopherBrandsdal]

Have you done it?

[@JohnGuest45]

@@ChristopherBrandsdal I think you could safety bet your house she hasnt ;)

[@denisdufresne5338]

I am sad for you because the way you did it is far from optimized. If you search on internet you will find some research about GAHT systems given you some tips about how to optimize such a geothermal system. The most important starting point is that to optimize the heat transfert in the 4 inches pipes, the air must stay in the pipes around 4 sec.. If it is less then the exchange is insufficient and more means that your pipes are either too long or the speed of the air is not fast enough. So in your case, of what I see, your pipes are probably too long. There are other points to consider like the space between pipes and the depth but I do not have time to explain everything here. If ever you do another one I strongly suggest you to read more about it to get more technical information.

[@scottfoster2487]

Clearly a non pro machine operator.

[@user-zb3qq1ul9c]

Я хуй знает чо это за шланг, но не проще было сделать из канализационных труб