Passive Earth Batteries Don't work

There are many passive earth battery or climate battery videos out there but if you notice they are all theoretical or planed construction projects. I have only seen one example where one was actually built and seems to be in operation. If you do a little engineering it is easy to see why that is. They just don’t work passively unless your climate is not that cold.

[@markyoung4555]

One piece of filming advice: turn off your running water while filming or wear a mic so that the water noise doesn't drown out your voice.

[@NANA-re6pw]

I find this amusing, having found this video after watching a bunch of Canadians in -40 degree weather able to maintain above -10 degrees with their earth battery systems. And that's just first versions, which much more room for improvement.

[@naturekins3247]

The Chinese style uses a berm of clay on the Northern outer wall of the green house (taking up no room in the green house )and a solar curtain of the glazed side that closes every night . This system keeps the inside above freezing up to -20 at night.

[@michbushi]

Instead of rigging the heat exchanger for the propane heater, you should simply vent it's exhaust into the greenhouse. Commercial growers do just that - first, you'd extract all the heat from it; secondly, you'd increase CO2 concentration in there, which promotes faster plants growth while using less water. Thanks for sharing your ideas, it is solid reasoning!

[@eddysgreenhousegarden7022]

You are absolutely correct however.......I am going to try and do this with solar power heating up water tanks during the day. But ya' know....using a small heater just for the CO2 isn't a bad idea. I know how much that helps growing plants but I would be afraid of someone walking in there and passing out. Hmmmmm ....another thing to consider. I am getting a lot of good ideas. Thanks. ED

[@christianlibertarian5488]

If you do that direct vent thing, carbon monoxide detectors are mandatory.

[@eddysgreenhousegarden7022]

Oh yeah....and a buddy system too. It is a little dangerous for sure

[@michbushi]

...I don't know if it is so dangerous indeed - what about indoor gas space heaters ? Something to check for sure

[@eddysgreenhousegarden7022]

Yes that's true. I do recall some friends who had one of those.

[@richardpockrandt7587]

I thought I was going to get some real information regarding earth batteries not just an option on why it isn’t a good idea for you.

[@Greenr0]

water specific heat: 4,200 Joules per kilogram per degree Celsius (J/kg°C). This means that it takes 4,200 J to raise the temperature of 1 kg of water by 1°C. water kg per gallon: 3.7854 kg water gallons per cubit ft: 7.48 gallon btu per joule: 0.000947817 btu stored by water per cubit ft per 1°C rise: 0.000947817 btu/joul x 4,200 joules/kg°C x 7.48 gallon/cubic ft x 3.7854 kg/gallon = 112.7 btu/cubic ft °C btu stored by water per 10 ft x 10ft x 1ft per 1°C rise: 112.7 x 100 = 11,270 btu clay specific heat: 878 Joules per kilogram per degree Celsius (J/kg°C). This means that it takes 878 J to raise the temperature of 1 kg of water by 1°C. water kg per per cubit ft: 51.71 kg btu per joule: 0.000947817 btu stored by clay per cubit ft per 1°C rise: 0.000947817 btu/joul x 878 joules/kg°C x 51.71 kg/cubic ft = 43.03 btu/cubic ft °C btu stored by clay per 10 ft x 10ft x 1ft per 1°C rise: 43.03 x 100 = 4,403 btu

[@sorinankitt]

When a trench has to be built in the wintertime and the ground is frozen, we would place insulation and poly sheeting over the future trench line for a day or two. The earth would become soft like summer ground. The earth is constantly putting high heat upward from within itself and the institution traps that heat. Some roads with frost heaving problems are rebuilt with large, very thick insulated panels laid down under the road and then covered over. The earth underneath has no chance of freezing and the air above has no chance of pushing down cold heat below the road, eliminating frost and heaving. The installation mistake with geo heating with pipes is that there is never any insulation placed above the piping to hold the heat down. The soil placed above the piping is not efficient enough to hold heat long enough to be released at night. It releases heat up into the greenhouse air as fast as the system forces heated air down into the piping from the passive system. Usually isolated panels are placed only at the sides and ends of the trench. Isolated panels need to be also placed above the piping area and the pipes should be covered with 3" rock instead of compacted soil, then fabric, then the insulation on top of that. You could put poly above the insulation or concrete to divert any runoff to a collection container for later use. You need the earth to push high heat up into the pipe area and stay trapped and mixed with the heat pumped down from the greenhouse into the pipes during the day. Then at night that heat will exchange in the earth return the heat in the greenhouse air.

[@eddysgreenhousegarden7022]

Sori, I have never heard it explained that way before. Very interesting. I learned a long time ago that the earth is pushing up heat all the time. There are effective ways of going after it. What you've explained makes perfect sense to me. Thanks

[@alekzgrablic538]

It's related to depth. From surface till 20-25 feet temperature change toward surface. It need to go deeper than that for stable temp.

[@creedsixteen891]

Water stores heat better than soil. You have a great point. I’m thinking 6-8’ of stone. Insulated. Do you think I could get some passive heat out of that?

[@DeDraconis]

Earth batteries seem to be more effective the deeper you go. Once you're 8+ feet down into the ground, the temperature there stays pretty consistent through out the seasons. It depends on where you live of course, but here in the US below whatever latitude our border with Canada is, the lowest I've heard it getting is ~40 degrees F. That's enough to knock off the chill and keep your green house from actually frosting over, and you don't have to worry about running out of that base heat level when running your system because the earth around it is constantly recharging it faster than the system can pull the heat out. Unless you had a ridiculously large system, really powerful fans (though tube size > fan speed in significance), and/or you closed your system off by insulating the space beneath your greenhouse, you won't ever manage to cool it down fast enough that you freeze the earth. If you're growing stuff that needs 50+ degrees all year round you're going to need something else to supplement it of course, if your ground temp is that low. I forget the average for the US but I think it's either 50-55, or 55-60. Definitely on the cooler side rather than the warmer. Geothermal is great if you have the time and resources to put it in; the efficiency of the fan and tubes moving air is "over 100%," sometimes "over 300%," and I shove that in quotes of course cause that's just comparing energy spent to run the fan vs kilo-calorie value of the temperature increase. The fan isn't actually creating the heat, the sun is. Still some good information in this video though. I'm wondering how useful/practical it would be to bury barrels of water underneath the greenhouse, between the tubing, since water has so much more thermal mass than dirt. Someone smarter than me would have to calculate the thermal expansion to see how full the barrels could be, and you'd simultaneously need barrels durable enough to not leak out over time, but also aren't insulators themselves which would defeat the purpose. All plastics are insulators, glass is fragile, wood warps, most metals would corrode from being buried and wet for years, or are poisonous. I guess copper barrels would work, but that's a loooooot of money to bury underground and never see again. You'd probably need weird shapes of either water containers and/or tubing paths so the exchange could reach, too. At that point you're probably better off just burying a radiator network and running oil through it rather than forced air, attach a compressor and just make your own heat and cold. I dunno. I live in the mountains none of this applies to me cause everything is shale about a foot down, and mountain mass does not work the same as actual below sea level earth does.

[@RayAntonelli2020]

It's Obvious you know a lot about this subject. Can you point me in the right direction to research burying water to add thermal mass?

[@DeDraconis]

These two links show some general info, but to be honest I actually /don't/ know a lot about the subject. I don't know if burying water will do much or any good, I was asking IF it would. I know with concrete you need to have a "glass to mass" ratio, let the sun beat down directly on it, and I believe with water barrells you also have the sun directly heating them up. If you bury water, you won't be able to do that. I was just wondering if you buried the water with the tubing running through it, if the water would be better than dirt for heating/cooling. www.ecohome.net/guides/2208/thermal-batteries-all-about-storing-solar-heat/ www.ceresgs.com/tips-on-using-water-barrels-in-a-solar-greenhouse/

[@eddysgreenhousegarden7022]

Ray, I will do a little video on the subject, how's that. Ed

[@scottrunge4077]

The heat comes from the earth itself, not the sun.

[@JohnGuest45]

@@scottrunge4077 The earths core is estimated to be 6000 deg C but very little makes it to the surface. The sun provides about 5000x more heat to the earth than the earths core. ;)

[@buffalo_chips9538]

Solar evacuated tube collectors can create a ton of heat even in the winter under cloudy conditions. Feed that into your water mass or even a solid mass and you can heat any space for free

[@TheExumRidge]

good news. is exactly my plan. transfer the solar heat into the greenhouse floor on daily basis.

[@mortgagefinancing5558]

Hello buddy great video ! I have been wondering what to do about heating a green house for awhile. Question though - In the summer should you empty the water out of the barrels? as they will heat the green house too hot. If you have metal drums I wonder what the best way to empty them is? Maybe drill a hole at the base and put some sort or drain pipe system going out side your green house ?

[@davefroman4700]

The number one issue with earth battery design is their implementation. They invariably are trying to push the hot air underground. That is not how the physics of heat transfer works. You always want to be pulling on the coldest part of the system. A vacuum on the system is REQUIRED for the energy to efficiently transfer out of the air and into the battery.

[@chetnash5991]

Excellent idea

[@christinemurray1444]

I'm looking for a solution that warms the interior by 10C or so in the winter and cools down the interior by ~5C during the summer at the hottest hours. Turns out the cooling is harder to do, especially at scale. Shading with common solutions gets you to +1~2C at best vs atmospheric temperature in the shade. To get down to -5 you need to start using active solutions like misting, split system air-conditioning, on top of ventilation of course.

[@eddysgreenhousegarden7022]

It's a tough problem. What works for cold doesn't work well for heat and vice versa. Good luck.

[@RetreatfarmFarmvilleVirginia]

I Am planning on using a split system with 4 inch perforated tubing buried in 30 inches of course stone and two long runs of 55 gallon black water barrels laying against the 70 foot long greenhouse walls. I'll be running several aquaponics/aquaculture tanks and am looking to simply balance my internal greenhouse temps here in Northern Maine in order to eliminate any expensive supplemental heating of the air and water in the tanks. Without any real depth to the underground thermal bank i can't expect too much change in temps with soil, but with varying sizes of stones starting with large 4-5 inch stone, then 1 inch, then granular crush and run for a top layer for leveling purposes i should be able to gain more storage advantage in less space to give me close to 20% gain, no more. So i'm starting out with low expectations on that design and relying a little more on water banking during the daylight hours then emitting the heated water and air in combination at night. With the water i was thinking of connecting all of the barrels together and pump them into radiant water pipe buried just under the crush and run layer of gravel to give me the ability to balance out the entire space with the same temp. air to eliminate cold spots like door openings that might leak etc,.

[@eddysgreenhousegarden7022]

That sounds interesting Tom. I know rock does hold heat better than plain soil. I will be interested to see how it turns out. Sometimes that is how it is. You have to try it and see. Ed

[@creedsixteen891]

I am in Manitoba Canada. I’m going to try the same idea here. It was -41 degrees Celsius here two weeks ago. Hard to fight that kind of cold.

[@mihaiilie8808]

Why dont you try a Rocket mass heater?It burns much less wood than a conventional wood stove.

[@mihaiilie8808]

@@creedsixteen891 Look into rocket mass heaters.Insulate the greenhouse well with double walls,the thicker the better.

[@specter2205]

To say that earth batteries don't work is ludicrous. The amount of mass of the dirt 6-8 feet down is huge...it's the earth. And about 48 to 54 degrees 8 feet down, given a reasonable length of tubing, will easily prevent freezing in the greenhouse. The problem that you have with them is that your greenhouse is already established, and presumably, you don't have the land outside your greenhouse footprint in order to run the couple hundred foot tubes. But for someone entering into new construction, it is definitely a worthwhile method to prevent winter freezing. It may not get your greenhouse above 55f, but it won't freeze either. If a greenhouse is not going above 45f during the day, then that's the maximum amount of heat capacity of the water, well below ground temperature. And over 24 hours and several weeks, you will loose that water barrel heat. I'm not saying that water is a bad method, it's good, water is a good heat sink..but only if you have sufficient sunlight to maintain that heat absorption. Many places in the northern US can go weeks without any appreciable sunlight. That's your heat source, the sun. The earth heat doesn't rely on the sunlight. It maintains that ~50 degrees year round, with the bonus of providing cooling in the summer, something water barrels cannot do alone.

[@eddysgreenhousegarden7022]

I don't think we disagree on anything. What I am trying to point out is there is a camp out there that thinks you can "charge up," the ground and get a 70 - 80 degree greenhouse at night out of it. In a really cold winter you can't do that passively.

[@JohnGuest45]

@@eddysgreenhousegarden7022 The other camp thinks the ground magically recharges with heat regardless of how much you pull out of it ;) The ground temperature doesnt remain constant at any depth with an active system, it will simply reflect the temperature of the new energy balance, heat in vs heat out. As an example, agshp could pull so much heat that the ground freezes, if the ground temp was a constant 48f-54f it wouldnt be possible ;)

[@rchristinck2243]

I live in ontario Canada and there have been winter's where people's water lines have frozen 8 feet down if those lines were under an area that has the snow removed, like a road or walkway or parking lot. I say that just to point out that the cold will drive down deep enough if given the time. If you are constantly drawing heat from the ground it will cool down and even possibly freeze. I do have greenhouses as well and with an outdoor wood stove manage to heat them at even the coldest temperatures... it needs wood as fuel. The earth battery sounds interesting but in our climate I am afraid that It would not work. In the greenhouses I do not heat there is frost in the ground. Perhaps in the shoulder seasons it may reduce the amount of wood we burn.

[@jordanfrisky8934]

External passive solar heaters every little bit helps

[@michaelfischer776]

You stated that you need to install the Earth Battery before you build your greenhouse is partially false. I say partially because if you are building one then doing it before you build one is the right thing to do. The false part is that you can modify a current standing greenhouse. Your false premise is that the piping would need to be placed into the ground below the greenhouse. This is the false part of your premise. You can place the piping six to eight feet into the ground that is not under the greenhouse. This would be called modifying a current standing greenhouse. Water has its advantages and disadvantages. A disadvantage, it freezes when pipes burst. Water has friction so the upkeep, maintenance and upfront costs are more with a water battery than an Earth Battery. I prefer to go with the most economical method and the most bang for the buck. Earth battery has been tested for a long time. To state earth batteries don't work is a false premise. (I did not say water batteries did not work, I said they were not the most economical way when compared to an earth battery).

[@sorinankitt]

The piping could be put in a trench alongside the greenhouse. More piping and a larger fan would be needed.

[@uniteamerica9446]

The temperature of the air coming out of pipes buried underground will be whatever your area's average temperature is. It's not the same temperature all over the world.

[@aleistergoodboo8982]

So why not just build your greenhouse on top of a gigantic sump tank that doubles as a heat sink? Or even more ideally, a large scale aquaponic system. I live in an extremely cold climate and am thinking about using Aquaponics to help make a greenhouse economically viable during the winter months.

[@eddysgreenhousegarden7022]

You said you live in a cold climate so I think that would all come down to how warm your soil is about 5 or 6 feet down. If it is 40 - 55 degrees or so, you might be able to work something out if your goal is to just keep things from freezing overnight. Remember if you are trying to keep your greenhouse warmer than that your going to need extra heat from somewhere. I have another video that explains some of this if you'd care to take a look at it. Here's that link. kzbin.info/www/bejne/qaHImXRufpJmnKs Ed

[@maxdw1]

I was thinking about burying a bunch of 50 gal drums or bigger ones. Could be under the greenhouse or not. Then you are getting the earth battery effect as well as the water. I would use multiple methods to heat the water including wood, waste oil and propane. Also I will likely put a radiator in the greenhouse in order to transfer the cold or hot, to and from the air in the greenhouse.

[@eddysgreenhousegarden7022]

If you want your water temperature to be higher than about 45 0r 50 degrees F, you better insulate your barrels very well. Otherwise your hot water will simply dissipate heat into the surrounding earth. The heat won't stay there very long.

[@HistoricSteamTV]

Glad I can pipe hot indoor radiator air into my greenhouse in winter LOL! I also boil a big pot of water at night like a crab cook size and the boiled water adds heat all night. Perhaps heating a can of used motor oil .... maybe not. LOL!

[@sorinankitt]

Water retains more heat better than oil because it is denser.

[@MrJesseh24]

You could build a rig to put both tanks ontop of eachother, then put your electric water heater beside them from what I can see.

[@eddysgreenhousegarden7022]

I think that would work but I also think it would take up space in the greenhouse. I already have a little room with some water tanks and a water heater in it. I am going to expand that room and use it for the water storage and water heaters. It's only about 20 feet away from the greenhouse so it won't take too much pipe to connect. If I didn't already have the little heater room, I would probably do what you are suggesting. It's a good idea. Ed

[@C3Voyage]

I'm curious how much solar you're using to supplement water heating. If not much, I can only imagine that all of your heating is by propane. If that's true, you are burning a butt-load of propane in those cold temps, right. If so, propane could be used directly as heating. It seems to me that water-radiated heat would simply provide a more thoroughly regulated heat. Maybe a more comfortable heat over air-heated?? Please correct where needed.

[@eddysgreenhousegarden7022]

Hi Brent, Well right now the solar is not contributing much. I have about 8,000 watts of solar power available and I have diverted all of that to our home when the sun shines. All of the greenhouse heating is being done by propane right now. I did that so I could gather data, thinking this data might be expensive . But it is not as bad as I thought it would be. It runs a high efficiency propane circulating water heater, and with that I can keep a 30 degree differential right now with an average of about 5,000 watts of heat consumption during the night. I have measured that with water flow rates and temp drops. I also have the aquaponics system and I think that helps level it out a little bit too. Since the propane is now dedicated to the greenhouse I have noticed that the consumption rate is much lower than it was, as you might expect. Using the data I have gathered doing this for a couple of months now, and doing a similar experiment on my home a couple of years ago centered on propane heat vs. electric heat, I figure I would need about another 10kwatts of solar power and another 1,000 gallons of storage water to be able to store enough heat on sunny days to heat the house and the greenhouse with solar most of the time. And that is considering I only get about 6 hours of good sunlight during the winter. I would keep propane and electric as backup systems The panels would cost about $6k or $7k but when I am on propane only (just the house) that amortizes out in about 5 years…..because propane is so expensive. I know there are a lot “holes” in the brief run down I just gave you and I hope I haven't wasted your time here. But I think there are several inherent “geeky” factors that would make this work. I would love to have you critique my "figures" if you would be interested in doing that Brent. It is always good to have another set of eyes on my calculations. Ed

[@C3Voyage]

Ed, no way brother. I am not smart enough to get into the weeds with you! Lol. I'm hoping you come up with a revelation that could cross over for me.

[@PrinceCbass]

vacuum evacuated solar hot water collectors on a drain back system would be much more efficient than using solar panels to create electricity and then convert it to heat

[@LibraGeek]

Hmmm to add earth battery system on existing facility would be to dig near or along outside the existing greenhouse and pipe it in/out from there without much more effort. So, nobody would be stuck with what they got per your comment.

[@eddysgreenhousegarden7022]

Well I suppose you are never really stuck. But if you don't put the earth battery right under the greenhouse, you will lose some heat to the surface.... then that portion of heat won't be going into the greenhouse where you would want it to go.

[@dropshot1967]

I don't know wich channel I saw this (some kind of workshop on building and installing solar heating, a long video with a lot of info), but using solar heat is far more efficient than using solar PV for heating water. Solar PV pannels typically only have ca 20% efficiency. Solar heat pannels, if I rememmber correctly, can reach between 60 to 90% efficiency. That being said, it is better to use exces solar PV to heat your water instead of just not using it, but investing in solar PV, just to use for heating is not always the most cost effective.

[@eddysgreenhousegarden7022]

Jelle,I really appreciate you commenting here. I have experimented in the past with solar heating panels. While they can be indeed a lot more efficient at converting sunshine directly to heat. That efficiency “effect” changes the game as the surrounding air temperature changes. The surrounding air temperature does not really affect PV net output. It does have a pronounced affect on a heat panel’s output. For example if it is about 60 or 70 degrees out and you can get a temperature rise of 60 or so degrees out of a heat panel you can get 130 degree water or air out of it. However when winter comes you will still only get that 60 degree temperature differential because of the inherent heat loss of the panels when it is so cold outside. So if it is 10 degrees outside that only gives you about 70 degrees at the output now. Water needs to be much warmer than that to be able store heat with it. You can do better than that with exotically engineered, vacuum encased or some other technology but that will be expensive. Looking at that……..Photo voltaic, with its 15% or so efficiency now looks much more cost effective during cold weather. Hope this helpsEd

[@PrinceCbass]

this is why you would use vacuum evacuated solar tubes as the collectors. The vacuum eliminates the issue of outside temperature because the tubes are "insulated" by the vacuum.

[@paulmaxwell8851]

Jelle is right. I have three hot water panels on my roof that keep me in hot water almost all the time. The Btus collected per square foot are far more than PV can deliver. BUT......they are evacuated tube panels, 20 tubes each. The flat plate collectors just don't work well in cold climates. I'm in British Columbia, Canada. Believe it or not, I can make water at minus 18-20C. Colder than that, the sun is unable to burn off the hoarfrost so hot water production stops. My woodstove with coil takes over. PV prices have been falling, falling, falling. Solar hot water panel prices have not. We have reached the point where heating water with PV is beginning to look attractive. A neighbour is trying that out right now.

[@kevinhansen7371]

Mine actually works very well, perhaps this gentleman just doesn't understand how they work.

[@immelting9834]

Mine only works because I hooked up a solar hot water system up to my 46 55gal drums . I also have over 5000 feet of 1 1/2 inch tube 5 feet under the footprint of my greenhouse. Its one giant loop that works perfectly for winter. It only gets down to about 35 here a few days a year typically 40 is cold here ( tennesse ) . BTW, my problem was my plants were blocking the sun from hitting the barrel. Now every is dialed in with the way it is now.

[@123Goldhunter11]

Instead of excavating the whole area for pipes just trench with a excavator. Copper or aluminum pipes might be pricey but good heat transfer-er.

[@unoriginal1086]

I want to use a climate battery in conjunction with other methods, namely the black water barrels on the northern wall and a propane heater if necessary. Im only planning on keeping it at 50 or maybe 60 to grow lettuce or carrots, and I live in southern ontarios so our winters arent warm but they arent freezing.

[@eddysgreenhousegarden7022]

From what you're saying here, I would think that's a reasonable expectation. My negative sounding title "Passive Earth Batteries Don't work," Is really aimed at expectations of 70 or 80 degrees (f) with ONLY passive methods when folks are living where winter climate temps can be expected to go well below freezing routinely. Sounds like you're on the right track. Good luck

[@unoriginal1086]

​@@eddysgreenhousegarden7022 Thank you for the response! Im just trying to keep above freezing, i might just go with a wall of black barrels instead of digging 5 ft.

[@isopodmike2204]

You don't have to excavate under the actual greenhouse if you have an established one and can run the pipes away from the greenhouse under lawn that's not being used.

[@eddysgreenhousegarden7022]

Oh I agree with that. It's just that so many don't have the room to run long piping runs under a large area, say a big lawn or something like that. So they have no choice but to put it "under" the greenhouse. If you have the room what you're suggesting would work well. Ed

[@frenchfryfarmer436]

This is what I am thinking. I have an option of an 8' pit to the east side of my new greenhouse. I old insulate top and sides. Fill would be free. I have equipment and some 15" alum manifolds and would use smooth wall pipe to avoid turbulence.

[@JohnGuest45]

The top 6 inches of your greenhouse floor will provide the same thermal storage capacity as 2000gal of water ;) Getting heat into the water depends on the surface area of the barrels and if you can bring all the greenhouse air into contact with it ;)

[@eddysgreenhousegarden7022]

I guess that depends on what that top layer is made of and how much moisture it contains. When I did my calculations based on typical soil composition it took more soil than that. But also keep in mind that heat likes to travel up. Warm air above the soil does not penetrate down very well. That's probably why systems that use that method always put the warm air in pipes a little deeper under the soil.

[@JohnGuest45]

@@eddysgreenhousegarden7022 I was working with my soil type and bone dry ;) When i was planning my installation i baked a cubic foot of the subsoil until it was bone dry so i had an idea of the worst mass weight and specific heat capacity. I find the top layer of soil is heavily influenced by the greenhouse air and direct sun. I have a sensor installed below my system which confirms heat moves downwards but it doesnt happen until late summer when the mass is warm. The sensor outside at the same depth (10ft) shows a similar trend but is less pronounced as the soil outside isnt as warm at depth due to being unsheltered and reliant on solar versus the sheltered mass and active heating..

[@eddysgreenhousegarden7022]

That all makes sense to me. It is interesting though that at ten feet down you are seeing a seasonal difference in temperature. I would have thought it would stay constant at that depth all year around.

[@JohnGuest45]

@@eddysgreenhousegarden7022 The only way to get answers is to sink sensors in the ground and monitor the temps over a long period of time. My system was installed in 2009 with 26 sensors scattered in and around it at various depths. I had sensors in the ground 12 months before i installed the system to get a baseline. The interesting thing is that over the years the sensors outside are only showing fairly small deviations to the baseline which is to be expeccted as the energy balance (heat in vs heat out) in that ground hasnt altered much. The sensors inside the system bear no resembence to the baseline and the sensors under the system showed an almost linear departure year on year until about year five when it levelled out. I concluded the ground had reached a steady state with regards to the new energy balance. I would view the heat that moves below the system and sideways at depth, more as dynamic insulation, slowing the movement of heat rather than as stored heat that is recoverable, at least not in the short term.

[@eddysgreenhousegarden7022]

@@JohnGuest45 That's very interesting. I would really encourage you to do a video on what you found. It would be very informative about a real world set up. If I understand correctly, it took about five years for the ground temps under your greenhouse to stabilize after you built it. That's very interesting.

[@RickWright722]

Ok this is the idea I would like to use , so please pass along some wisdom. I live in Kuwait.... yes Kuwait!!! I’m only worried about freezing 30 days out the year. Heat is my problem and with a earth battery we can use less power to cool the green house along with a water wall. My friends raised in this area have stories of desert people using thermal batteries in the past for cooling houses before electricity but that history is lost in technology.... I’m from Detroit, I have no understanding of desert 🐪 life, but I understand heat transfer. We have man made pools and wells on our farm. My plan is to dig down 10-15 feet , from watching this video place four or 5 plastic barrels just as you did make connections between the barrels and the well or pond water. Make a air connection to run through the Same barrels which should give me additional cooling. There are no videos that talks about green house farming in the desert 🐪. Sadly I am figuring this out by looking at all you cold weather greenhouse experts and trying to reverse engineer your steps.. is my theory sound or am I missing something. At first I thought that an earth battery would be enough, but you gave me this new idea. Thank you for your video.

[@eddysgreenhousegarden7022]

I don't think burying some tanks in the earth will work for your case because even if you put them ten feet down, they would heat up and dissipate too much heat into the surrounding ground and saturate it heat wise. The reason is they don't have the surface area in contact with the ground that would be needed to get rid of the heat being picked up in the greenhouse. You need to dig a hole about five or ten feet deep and measure the ground temperature down there. Out in Kuwait I don't know what it would be. Here it is about 55 degrees f. If you can get temps in the ground below 60 degrees or so, you could do this. But you would need to use a very large surface area in contact with the ground to dissipate the heat effectively. Here's a link to another video of mine that explains this. kzbin.info/www/bejne/d6PYc4SBrbVsh5Y This video is of course talking about heating a greenhouse instead of cooling it. But the same principles would apply. Take a look and see if this helps. Also.....Doesn't Kuwait have low humidity? If that's true evaporative cooling would work great for you out there. I think it would do a lot better than what you're thinking of doing right now. Ed

[@RickWright722]

Eddy's Greenhouse Garden My theory: 1. If we dig 12 ft down. Place Blue plastic barrels in the hole. 2. We have a well and irrigation pond on the farm. Split off from the well and connect it to my buried drums. The last barrel has a pipe running water out and back to the pond. 3. I will run the geothermal pipes through the barrels. Keeping them water tight. Everything else would be the same as the rest of the geothermal community, except we have sand and dirt and not rock. So tell me am I imagining success where there is none. Yes we also use the water wall(swamp cooler) for cooling but like I said Kuwait is really hot. Using geothermal would be additional cooling with lower use of electricity and cost.

[@sarahloy2699]

Thank you for exploring alternatives but I am afraid you miss understand the earth battery. The earth battery system is not meant to be a day/night system. It stores heat all summer and returns heat all winter. If folks want more info on earth batteries I hope you will explore info elsewhere.

[@eddysgreenhousegarden7022]

Sarah, I would really like to see a demonstration of that. It's all over the internet as a theoretical thing but it's just not possible, unless you are fooling yourself because it's really not that cold outside during the winter. What you're telling me is not that much different than saying if I take a car battery and charge it up all summer, I can use it all winter before it will run out of power. It's just not possible. A mass of earth only has a finite amount of thermal energy it can store. Volume wise, it is much less than water. Even a small, well insulated greenhouse is going to require about a 5,000 watt heater at night to keep it from freezing. If the night is only 6 hours long that's 30 Kilowatt hours of power. If the winter is only 90 days long....that's 2.7 Mega watt hours of power. You just can't store that amount of heat energy in the dirt under a greenhouse. It's physics.....it's not possible. Ed

[@karlInSanDiego]

Hi Sarah, we built one and in our experience, it is a good day/night system but would never work as a whole season system. After several hours of use in hot, the ability to cool dissipates. After several hours of use in the cold, the ability to heat dissipates. As you exchange heat, it has to go somewhere (thus the concept of a battery). But the soil does not have a limitless potential to draw away heat, and even if it did, it would not be able to give it up over the course of a season later in the year. The exchange has limits and if you're trying to affect air temperature in an open air system (all greenhouses need air exchange with the outside), it is an amazing amount of energy. Fortunately the sun provide excess energy every day, if your greenhouse is well insulated, and all greenhouses can capture excess heat during the day.

[@eddysgreenhousegarden7022]

Very well said. Thank you for your input. Ed

[@JohnGuest45]

@@eddysgreenhousegarden7022 I agree, seasonal storage is very difficult. When designing an earth battery you have to consider the local climate and how many sunny days you might get in the winter. A long run of cloudy days will discharge the battery but an hour of winter sun in the day can get you through the same night. A lot of folks think water is the best medium but capacity isnt the important thing when the amount of heat available is limited. If you disperse x amount of heat into a large body of water you wont see any useful temperature rise. If you put it into the ground via perforated tubing it isnt dispersed into the mass..it remains close to the tubes where it can be accessed during the night. On my experience, any heat that moves further than a foot from the tubing cant be accessed the same night. The conductivity and diffusivity of soil is often seen as a disadvantage when its acually of great benefit.

[@Greenwashedhipppie]

In my climate I am sure an earth battery would turn into a mold factory.

[@eddysgreenhousegarden7022]

Another thing to consider. I didn't even mention that part......Thanks. Ed

[@PrinceCbass]

with proper airflow the mold is not a problem and is actually less of a problem because of the increased airflow and circulation.

[@JohnGuest45]

@@eddysgreenhousegarden7022 Another myth, i paid a drain company to check my tubing with a fibre optic camera 5 years after it was installed, no mold. I also tested with filter elements designed to catch spores etc from the outlet airstream which were sent to a lab for culture testing, basically put in a petri dish to see what grew. The result was nothing that would cause harm. The only thing i would be concerned about is radon, carry out testing before installing a system if you live in an area where its prevalent,

[@mustafaibnabdullah6392]

Heating those gallons to 140, i assume you dont grow fish in them?

[@eddysgreenhousegarden7022]

No that's not the pond water with the fish. It's a separate heating system.

[@marcoloretto1185]

you filled in the last piece of my Marcopini! Thank you! YES, WATER!

[@eddysgreenhousegarden7022]

"Marcopini?" I like that.

[@marcoloretto1185]

@@eddysgreenhousegarden7022 I’ll send you the diagram. I’d love to hear what you think of it

[@eddysgreenhousegarden7022]

@@marcoloretto1185 Okay

[@offgridwanabe]

How about if I bury my water barrels in the green house?

[@eddysgreenhousegarden7022]

You could do that but in the winter you have to remember underground, depending on where you are, it is going to be around 40 - 50 degrees and any water you store heat in is going to migrate to that temperature a lot quicker than you might think. The good thing about that is it works the other way around too. If you are only interested in keeping the greenhouse from freezing, it might work for you because if you draw low grade heat (40- 50 degrees) out of it, the earth it self will replenish that heat.

[@offgridwanabe]

@@eddysgreenhousegarden7022 I going to heat the water with vacuum tubes

[@eddysgreenhousegarden7022]

@@offgridwanabe I think you're going to need to insulate the barrels. A good analogy is if you dig a hole, say four or five feet deep, then lower a barrel of hot water down and cover it up, how long will it stay hot? It will want to get to that 40- 50 degree temperature down there in the hole. If you insulate it.....you can slow it down.

[@talshaharfamily]

Hey y'all: www.citrusinthesnow.com/ and watch the companion KZbin interview: kzbin.info/www/bejne/kHXCZJKdqMympM0

[@thuss5162]

See with air you can also cool! I'm using both

[@lukepowers9472]

T Huss how deep did you go?

[@lukepowers9472]

And where do you live

[@jimh712]

If you are going to try to store heat in the soil... You'll need to insulate the area you want to heat..

[@eddysgreenhousegarden7022]

I agree with that. But it gets expensive to insulate it. Also the earth really doesn't store energy very well so you need a pretty good sized area.

[@JohnGuest45]

@@eddysgreenhousegarden7022 You only need to insulate the perimeter using 2" eps installed vertically. Most folks can manage to dig a narrow trench a few feet deep ;)

[@alanmcrae8594]

And then there can also be issues with changes to the water table. If underground water changes direction and hits your earth battery, then it's game over. Water will drain away any underground heat storage very quickly. Using active heat storage could give you multiple options for collecting, storing and distributing heat - which improves fault tolerance and would allow you winter heating options even during an extreme weather event like a Polar Vortex Breakout or several back-to-back days of subzero weather & overcast skies. When your greenhouse becomes one of your primary food sources, then it is no longer a "isn't this cool" hobby any more. It HAS to work, and any crop losses could mean you either go on reduced rations, go hungry or go begging. I have looked at a few earth battery greenhouses on KZbin and I haven't seen solid, scientifically monitored results yet. Anybody can put some cheap temperature logging devices in their greenhouses to log both indoor & outdoor temperatures throughout the heating season. Never mind the anecdotal claims or showing the build but not operations - show us your seasonal historical data.

[@EdbbieRosado]

So it's not that it doesn't work but more of for your already established GH with a water system it's just not feasible.

[@eddysgreenhousegarden7022]

I suppose that's one way of looking at it. But there is also the strict definition of what an earth battery really is. That term "earth battery," is used to describe a range of things that either don't fit the definition or make claim to things that are not possible. Ed

[@MhUser]

or you can buid a sauna inside your greenhouse and enjoy it during the winter; heating the green house will be a side effect

[@eddysgreenhousegarden7022]

If I got enough to power to power a sauna, wow I'll really have something. It's not likely though. But a sauna is not a bad idea in any case. Ed.

[@dr.feelgood4266]

Eddy's Greenhouse Garden you can make 175v earth batteries and recycle ♻️ plastic watch this kzbin.info/www/bejne/fJfFaGuljcqcfas

[@svartvist]

The same principles upon which HVAC heat pumps work apply here. There is a limit to how many BTUs can be pulled/pushed in a given volume of earth. Nobody is going to get enough heat stored in earth material to last all winter. There simply isn't enough density in a cubic foot of earth to do that. Even with an insulated earth bank, the heat loss will conduct whatever reserve is available in a matter of days. If a person wants to pump the numbers, get an old copy of Audel's HVAC book. Some of the comments here are wryly humorous, as the effectivity of various materials for storing/delivering heat were commonly published back in the 70s. It goes roughly like this in ascending capacity; Earth Stone Concrete Water/glycol mixtures Glauber salts I fail to understand the rationale of building a system with no planning and estimating the requirements, and certainly not making claims of performance without data. This is a waste of resources, effort, time, and is merely reinventing what has been known for quite a while. Plain water weighs in at 8 1/3 pounds per gallon, with 7.49 gallons per cubic foot. That equates to a volume of approximately 8' x 8.5' x 4' for 2000 gallons. At one degree F rise per pound of water = 1 BTU, that yields a capacity of just under 17KBTU storage for every degree rise of the water above ambient, up to the boiling point. For the volume of space and installation expense, earth will not compete with the cost and flexibility of a hydronic system. Having built my own hydronic heating for my house, using a modified NG water heater and welded up my own water heating wood/coal burning stove, I proved what I found in the literature doing the research beforehand. The wood stove was a fast burner, running at roughly 55% efficiency. I had to operate the stove in that mode because hydronic heaters are designed/sized to operate with a minimum water temperature of 160ºF. In a slow burner water saps too much heat out of the fire and extinguishes the burn--especially using coal. For the investment of money, time, efficiency, versatility, and maintenance, your choice of hydronic heating is the most optimum solution, Ed.

[@elearnej5524]

depends how deep you dig, above 12 feet deep you will get bigger variations but if you go to the depth where winter/summer becomes irrelevant then you get an almost infinite heat source ie around 50 feet deep at 45 lat. would give a constant 54F year round. now obviously its probably not cost effective anyways to do that so a water system will be a lot better. Also i would point out this new thing called zeolite, if you really wanted to push a earth battery system and funds where not a limit, then using that would be better then water cause its actually 4 times better at storing heat then water.

[@eddysgreenhousegarden7022]

That's really well said. Thanks

[@FruitingPlanet]

You are wrong, yes water has about 4 times the heat capacity per mass, than most soils and rocks, but mass constraints are irrelevant, for a greenhouse heat battery. Rocks and soil has 2-3 times the density (mass/volume) of water, which means the effect of the better heat capacity of water is severely reduced, by the higher density of rocks and soil, volume is our constraint in a greenhouse but not so much below the greenhouse and dirt/rocks are often free to get, therefore they can in many cases make more sense than water for storing heat.

[@eddysgreenhousegarden7022]

Do you have one that is actually working?

[@FruitingPlanet]

@@eddysgreenhousegarden7022 I have seen both in person and helped build one with an earth battery, both systems can work if they are built correctly. If you have enough space on your north wall which you don't need and cheap access to large metal barrels, this method is probably the best for you, however if you want to use all your space /north wall and have a large greenhouse or are designing a new one, the earth battery is probably the better choice.

[@eddysgreenhousegarden7022]

@@FruitingPlanet Just to be clear, some people think an earth battery is something you can change up all summer then extract the heat you put into it during the winter. They think you can pull 70 degree (f) heat out of it somehow during the winter because you put all that heat into it during the summer. That definition is what I am saying doesn’t work. Pulling the natural heat from the ground, from below the frost line in the winter…that does work, but it’s not because someone put any heat into it during the summer. It is a natural state of the earth no matter what you do. In any event the natural heat you can get is what I call low grade heat. It is perhaps 40 - 50 degrees and you need a large surface area to recover it. That can work but it will only keep your greenhouse from freezing temps during the night.

[@FruitingPlanet]

@@eddysgreenhousegarden7022 it's certainly possible to achieve, but what many don't realize, it's that it takes a lot of mass and good insulation from 5 sides. The typical geothermal greenhouse you see, will of course have minimal heat storage over the span of month, however as you said, it can still prevent freezing in many cases throughout the winter of it is done well, store the heat of sunny winter days for the night or cool in the summer. However if the system and greenhouse is fairly large, probably insulated with four example double layer "Ytong ThermStrong"/other kinds of highly insulating porous concrete, or double layer hollow brick blocks with rock wool in between and it has a proper ventilation system, maybe even heat pumps, you can most certainly achieve year round tropical conditions in zones 5+ with low to medium electrical input.

[@jayhayward7579]

@@eddysgreenhousegarden7022 Agreed. This is not how an earth battery works. I've seen this idea floating around a lot these days. BTU loss in an average size greenhouse (24'x72') can be as much as 100,000 btu's / hour in the dead of winter. If you take the dry volume of your earth battery (24'x72'x4'= 6912 ft^3) and multiply that the average heat capacity of 1 cubic foot of soil (63.18 btu / ft^3 * C), you will get 436,700 btus. The calculations are a bit more involved than this. However, this means that if you are able to raise this volume of soil by 1C, then you will get about 4.5 hours of heating for your greenhouse. This soil volume is actually an overestimate so you will likely see less btu's stored per 1C rise in soil temp. Moreover, the cost of materials and installation of a well-done GAHT system is prohibitively expensive compared to heating a GH with a wood stove and storing energy in water. People are actually walking around saying that soil and rock can store more energy than water. www.researchgate.net/figure/Density-specific-heat-and-volumetric-heat-capacity-of-common-soil-components-at-20C_tbl1_279595517 Science...

[@countrylife392]

Water will freeze where I live

[@eddysgreenhousegarden7022]

That is one weakness. The water has to keep flowing and the water needs to be heated or it will freeze. But if the object is to keep the greenhouse from freezing, you'll have to heat the water anyway.

[@lisalister8002]

The running water sound is ANNOYING!

[@masterginxx]

So this guy doesn’t have an earth battery but explaining why it can’t work.

[@eddysgreenhousegarden7022]

Experience is always better but this is physics. You don't have to actually try to boil a bucket of water over a single candle to know it won't work......now do ya?

[@masterginxx]

@@eddysgreenhousegarden7022 There is plenty of proof that the earth battery design does work though. Dont be so stuck in experiece that your not willing to discover something different .

[@JohnGuest45]

@@eddysgreenhousegarden7022 The vast majority of folks with these systems are not too good at physics judging by their design choices.

[@joshuaklind]

Turn off the water so we can hear you!

[@ramblinrebel1]

so, they do work, just not in your climate. The truth is that they work, they work in every Ant Den ever dug by ants. Video mislabeled.

[@eddysgreenhousegarden7022]

When I uploaded this video, about 4 years ago, there were a lot of people claiming this would work and work very well in much worse climates than mine. That was really the point. I have to agree with you, if you have a proper climate you can make it work.

[@4helex]

An earth battery is charged with heat all summer long by blowing heat into it with a fan. It can take months to raise the temperature of the earth several degrees so that energy is waiting to be extracted in the winter.

[@joansmith3492]

You are disappointing here. It doesn't sound like you have done much research regarding earth batteries. Of course you have to plan for it before you build your greenhouse. Duh! Would you think about digging a basement after you build the house? I have seen many you tube examples of successful earth batteries. Curtis Stone has one, some guy in Colorado, Verge permaculture come to mind. You don't seem to have any personal experience with them either, therefore I doubt your information is accurate.

[@eddysgreenhousegarden7022]

But they are not passive.....they are using a heat source of some kind to make it work. Don't forget that. Earth batteries do work if....like you say, you build it first and ....you add heat...or it is not really that cold during the winter. I would love to be proven wrong actually. I would welcome an example. If there is one.....there is something to be learned. Thanks Ed

[@eightdragonkings]

Well said Eddy. Joan hasn't built one herself and then decides she's an expert. Passive solar greenhouses have been tested for three decades or more and it keeps coming back to water as the primary heat storage.

[@eightdragonkings]

I would just like to add a suggestion Eddy.... Have a look at rocket mass heaters. If you put the rockets mass under the barrels I think you'd find a huge benefit with little fuel use.

[@eddysgreenhousegarden7022]

Jeff, I think Rocket mass heaters are pretty neat things. The only drawback is you gotta' feed the stove and I'm kinda' lazy that way. However........if you could get the "mass" part to be water...as in perhaps something like the old steam locomotives, i.e. fire tube boiler configuration......hmmmm. You might be able to heat a whole lot of water in a short period of time. The only thing that comes to mind right now is old natural gas water heaters, connected together, end to end, laid out on an incline, circulating water through them. I might try that. Thanks. Ed

[@eightdragonkings]

If you put metal water barrels right on top of the mass and insulate all around and underneath it, the heat will have to migrate upwards into the barrels no? The good thing about a rocket mass heater (RMH) is that you only have to fire it every couple days or so. Simple cheap and effective.

[@ionpopescu4303]

You are talking when the water is flowing ! Hard to understand you

[@eddysgreenhousegarden7022]

You are right about that. I really should take this down and do it over.

[@jeffg3575]

The sound is rubbish get a mike.

[@eddysgreenhousegarden7022]

Yeah.....I know. This was recorded about two years ago, so it is what it is.

[@poosmate]

Had to stop watching because of the water in the background. However, recovering heat from the ground is nothing to do with it being an earth battery. An earth battery is where you put rods in the ground (say carbon, graphite or copper, and an opposite material like magnesium, zinc or aluminium) and draw a (very low) current of electricity off them. Evenso, I would have carried on watching if it hadn't been for the water noise. Poo

[@eddysgreenhousegarden7022]

The whole point of this is that there are a lot of people who think an earth battery is a heat storage device. A heat storage device that you can charge , like an electric battery. I can't disagree with your example of a battery, but that ain't what I was talking about. There's a community out there with a different definition. And it has nothing to do with electricity. Ed

[@creedsixteen891]

Water stores heat better than soil. You have a great point. I’m thinking 6-8’ of stone. Insulated. Do you think I could get some passive heat out of that?

[@eddysgreenhousegarden7022]

I know in the old days they used to heat stones and put them in carriages to keep your feet warm. So it works. It's just how much stone and what is surrounding it to keep the heat loss down.

[@paulmurgatroyd6372]

Water stores heat better than soil. You have a great point. I’m thinking 6-8’ of stone. Insulated. Do you think I could get some passive heat out of that?

[@eddysgreenhousegarden7022]

Oh certainly. I'm not sure how much but when I looked all this stuff up, as I remember stone was better at retaining heat than soil was.

[@creedsixteen891]

Water stores heat better than soil. You have a great point. I’m thinking 6-8’ of stone. Insulated. Do you think I could get some passive heat out of that?