Intro to GAHT® (Ground to Air Heat Transfer) Systems

For more information on our GAHT® System or to order plans today, email [e-mail] !
A Ground to Air Heat Transfer system can provide sustainable heating and cooling for year-round greenhouses by taking advantage of passive solar heat of the greenhouse and the thermal mass of the soil underground. While simple in concept, GAHT® systems require the right materials, layout, and installation to be effective renewable energy heating and cooling system for efficient greenhouses of all sizes. This webinar will address how a GAHT® system works, it’s major components and gives an overview of how to install one.
Visit www.ceresgs.com/?... for more information.

[@markdaigle4904]

Very Interesting Webinar. I am new to greenhouses and am looking for a way to utilized it over the winter. I will be doing some more research on this.

[@YoubieTuber]

A guy in BC Canada has a great setup using bubble wrap. My wife and I utilized it and we are still producing tomato’s and peppers. Here’s the link. kzbin.info/www/bejne/bIPOmHmGbLmJiJI

[@TheKlickitat]

This idea is centuries old and it seems that people reinvent the idea every decade or so. I love the tech but find it funny that we constantly have to relearn the idea.

[@tomsexton4880]

Thank you for the wonderful education.

[@CeresGreenhouseSolutions]

You are welcome. Feel free to contact us if you'd like more information

[@katherinebialek443]

You mentioned the system is a positive pressure system, so nothing should leach in through pipes. It is easier to grab air and move it at the lower outtake. Would that cause a negative pressure system, and is that bad? Are possible solutions two fans, or neutral pressure? Or different strength fans to keep positive pressure? Thanks!

[@jamesalanstephensmith7930]

Great stuff!

[@resilientfarmsanddesignstu1702]

Heat is transferred to the surrounding soil at a constant temperature when water vapor in warm high humidity air condenses to water. This occurs when the temperature of the moving air drops below the dew point. This same amount of heat is transferred from the soil when the temperature of the cold lower humidity moving air rises above the dew point (whereupon it can accommodate additional water as vapor causing a rise in humidity). Where cold and warm, high and low humidity of the air moving in the tubes are relative to the temperature and humidity of the air in the surrounding soil.

[@royormonde3682]

Great video, I've been thinking of building a greenhouse (maybe 12x20) and have been researching these systems. This is very informative, nice work. I'm in a zone 4, so it's cold in winter, not even sure if I want to use it in winter, but certainly early spring and late fall. Around here I can only find weeping tile with a sock on it. Do you recommend this be removed or does it not matter?

[@robertj.wiltshire1553]

I am designing a commercial greenhouse utilizing one of these designs, everything I have found says the weeping tiles with the socks are the way to go. You don't want debris to enter your heat pipes.

[@royormonde3682]

@@robertj.wiltshire1553 That's great thanks, I knew the debris was a factor that benefits from the sock, just wasn't sure about the sock retaining humidity and not dispersing it quickly enough in relation to the air flow being so high. It's probably not a factor I need to worry about, but I'd hate to find out later I had excess mold issues because of it and I've found no conversation on the subject. I'm just trying to cover all bases, that's one part of the build you can't change or modify later. I think I might just lay down a couple of inches of gravel under each branch before returning the soil back will ease my worries.

[@CeresGreenhouseSolutions]

Good question. We recommend that you use perforated piping with a sock covering so that condensation can drain and you don't get debris in your system

[@brianpimental2948]

Informative thank you

[@CeresGreenhouseSolutions]

We're happy this was a useful resource for you

[@zemyazahealingkorllc]

Good video

[@marcoloretto1185]

I am in NC at 3400ft. I am combining a few things I have seen that seem very relevant. The GAHT is definitely the way to go for my Walipini. Does the soil dry out if the pipes are too shallow? Also, I am using aircrete for structural and insulation. Any comments?

[@CeresGreenhouseSolutions]

Thanks for your interest in a Ceres GAHT®. There are a couple of issues with the pipes being too shallow: 1) The pipes might interfere with the plant roots. 2) The heat isn't stored properly and radiates back into the greenhouse rather than being saved for when you want to use it. Please reach out to us at [e-mail] or www.ceresgs.com/contact/. We would love to help you with your project.

[@tenacioustim9780]

Great video. Do you have a desert version? I live in las vegas, and want to cool my greenhouse as best i can. Do i follow this same design? Is there any tweaks i can make such as a deeper ghat?

[@CeresGreenhouseSolutions]

Since the GAHT® works well to cool the greenhouse as well as heat it, you would follow the same design with a slightly different installation method. Instead of installing the GAHT® underneath the greenhouse, you would install it outside of the greenhouse footprint on the north or east side of the greenhouse (where it's shadier). You would also want to dig further down to access cooler soil temperatures. We would also recommend that you not insulate the system. For more information, feel free to email us at [e-mail]

[@tenacioustim9780]

@@CeresGreenhouseSolutions you guys are awesome. thanks for taking the time to reply!

[@boxelder9167]

I am thinking that you could incorporate Bernoulli's principle by using a smaller intake pipe diameter outside of the greenhouse and providing a larger pipe diameter to exhaust out the top of the greenhouse. As the air is drawn in it’s velocity increases which decreases the pressure causing it to lose heat. Similar to a propane tank frosting up while it’s being emptied. You aren’t getting the change of state but it’s still cooling.

[@missingthebeach218]

I have been using a gaht system now going into the 3rd winter. It has a larger fan on a aprox 30x40’ greenhouse. It has sandwich insulated walls & poly corrugated roof. At about 6500’ in Colorado, zone 4. An additional fan/vent to dump heat in the summer is needed as well as swamp cooler. I also have electric heaters to help keep the freezing temps out in winter. My 2 complaints, 1- the fan is loud, maybe an inground vault for the fan would keep the noise down. ? 2-the mechanical thermostats have never worked right and need to be calibrated. Through time they are 30* or more off. Maybe a digital one would work better. There are also electrical switches that open/close vents from stack to outside air for winter/summer and they have never worked after the start. Our temps can range 50+* within a day, so this was the customized system but the electronics bring challenges.

[@CeresGreenhouseSolutions]

Thank you for your comment. Did you purchase your GAHT® system from Ceres? If the fans and the thermostat are becoming a big concern, please reach out and one of our GAHT experts would be happy to assist you in coming up with solutions.

[@l...]

Use KZbin chapters please So we can share each chapter

[@mrpush2532]

Hi, ok so you don't use bottom insulation. But depending on subsurface temps, heat you pump there can and will flow outside the battery from the bottom. Its like using an insulated cooler with no top or bottom. That does make sense unless the temp differential is very small. What differentials do you actually get? Thx.

[@jimfyffe9543]

This type of system is only balancing the temperature in a 24-hour period with no insulation on the top or the bottom there's loss but the ground holds it so well it's minimal in that short time if you want to use the heat or the cooling for a longer period of time top and bottom must be insulated and condensation must be removed manually

[@BigBirdy100]

Very helpful and informative video. Would be good if the next time you make a video if you wouldn't trail off the end of your sentences, as in volume.

[@nadyamattison8603]

Interesting video. Thank you. Why do you not coil up the one long 6' pipe from one corner to the other instead of fitting 4' pipes in 6' short pipes?

[@CeresGreenhouseSolutions]

Hi There! Thanks for reaching out! By using several smaller pipes, instead of one longer larger pipe, we are able have more surface area of pipe in contact with the soil and therefore, get more thermal transfer, and in turn, a more efficient GAHT system. If you'd like to learn more, feel free to reach out to us at www.ceresgs.com/contact/

[@montanatinboxliving1408]

Why do you use perf pipe vs solid for the runners? Getting ready to do my GAHT system here in Montana. My plan is to do this in a new garden area since greenhouse excavation would be a PITA. I will then use that space for my big compost piles so there will be an insulating cover (actually heated) all winter long.

[@CeresGreenhouseSolutions]

the perforations in the GAHT piping allow for moisture in the air to escape so there's no build-up in the piping.

[@montanatinboxliving1408]

@@CeresGreenhouseSolutions thanks for quick response. You aren't insulating below the pipes at all are you? Just the sides?

[@CeresGreenhouseSolutions]

@@montanatinboxliving1408 We are just insulating at the sides, yes

[@sailingmohican2767]

Actually putting your compost in planters on the walls of your greenhouse adds quite a bit of heat

[@erich4329]

This is similar to Russ Finch Geo-Air system "Citrus in the Snow"

[@michaeleeten7783]

Just finished a system in a 15 x24 gh. Used 18 inch center pipe 10 inch pipe on either end. The large pipes are twin wall which allows the 4inch pipe to snap into place. Used two 10 inch fans from ac infinity with a controller blowing in and a 16 inch shutter fan drawing out of a barrel. Was thinking 5 exchanges was the air cycle. Have run the fans none stop. Started at 90 percent and have worked down to 60 percent. You mentioned Humidity as changing the capacity of heat exchange. Do you have a range in mind. Hope this makes sense without pics.

[@CeresGreenhouseSolutions]

Hi there, thanks for reaching out. Did you build a Ceres GAHT® system? Please contact us at [e-mail] with your question and we will have a GAHT® expert reach out to you to see if we can help

[@chip63us]

Sir, chlorine dioxide perhaps would sanitize the system, forcing vapors through, amazing stuff, short lived.

[@amirhosein8948]

Great video. I was wondering how could the optimized fan velocity/CFM be determined?

[@CeresGreenhouseSolutions]

We have proprietary formulas that help us determine fan velocity appropriate to the final design. Inline fans range from 8"-18". For more information, feel free to reach out at www.ceresgs.com/contact/

[@tefinnegan5239]

@@CeresGreenhouseSolutions proprietary math? 😆

[@smarthomesecurityny]

​@@CeresGreenhouseSolutions ⭐ Hi, have you had any issues with mold in the pipes or a negative effect on air quality?

[@smarthomesecurityny]

Have you had any issues with mold in the pipes or a negative effect on air quality?

[@Horse237]

I get 53 inches of rain per year in my area. I would prefer to use a non-perforated tubing like Russ Finch uses in Nebraska. I am further south and at a lower elevation so my ground will not be as cold and I won't have a huge difference between day and night as people do in mountains.

[@CeresGreenhouseSolutions]

The GAHT® works fine in areas of high rainfall, we would love to partner with you to help create a great growing space. Please contact us at [e-mail] for more information

[@saqlainmohiddin1280]

sir, I need mathamatical calculations or formullas which can be used to calculate how mach heat energy is abtained from soil, lenght of burried pipes etc, plz help

[@CeresGreenhouseSolutions]

Hi there, I am not able to give you that info through this platform but if you email us at [e-mail] or fill out a submission form on our website: www.ceresgs.com/contact/ a GAHT® expert can help you with your questions.

[@kennethvogt9379]

Does dehumidification from the GAHT system require humidifying the greenhouse?

[@robertj.wiltshire1553]

As long as you have fresh airflow into your greenhouse system, I have never encountered a situation where you would have to purposefully re-humidify your greenhouse.

[@cosmo0080]

hi you 2 sets of pipe 2ft and 4ft does this depth change with the depth of the frost line ?

[@CeresGreenhouseSolutions]

It does indeed, we customize GAHT plans according to your location and climate.

[@JohnGuest45]

If you have perimeter insulation installed (which you should) then the answer is no.

[@maryhornbostel6959]

Would a sump area for the GAHT pipes to drain into and be pumped away work if the water table rises seasonally? Another system uses pipes outside the greenhouse footprint 8 feet deep and 225 feet long for a 75 foot by 12 foot greenhouse. Would this be a better system if you are trying to grow citris trees in the ground? Would the trees invade the pipe system, or would they air-prune?

[@CeresGreenhouseSolutions]

Thanks for your question. It's possible that a sump area would work. We have suggested to a few clients that they install a sump in one corner of the greenhouse to deal with an occasional high water table. If the water rises enough to encroach on the GAHT​®​ every season, it might not be the right solution. And as far as your other question, our GAHT​®​ designs have the first layer below 18" and we offer custom designs that can take root depth into account. Even if the roots grow lower, I do not believe they will intrude into the piping, as the roots will seek out moisture and nutrients. Roots commonly invade septic system lines because both moisture and nutrients are found in them. This is quite different than our GAHT​®​ system. If you have more questions, please email us at [e-mail] or ceresgs.com/contact/

[@johndouglass3691]

How far below ambient can this go?

[@moeinrahmani1395]

does this system work in a day desert with 50 degree celicius at summer and -10 at winter ? the air is harshly dry in my area!!!

[@CeresGreenhouseSolutions]

The GAHT® will work in the winter to help keep the greenhouse warm. During the summer a different method of cooling will be required. We would love to partner with you to help create a great growing space. Please contact us at [e-mail] for more information.

[@PYehl1]

I'm working to design a system for my future 10x18' build. I'm thinking about having a 10" input & exhaust lines with both 4' and 2' depth lines attached (like you did on commercial build). Will have 5-6 4" lines going across. With 10" fan that might be over sill at 1200 CFM (but has speed controls to back it down if needed). Would you suggest 2 systems with 6"-4" lines or is the one system with 10"-4" lines ok? Also now with automated plugs - you could setup IFTTT rules based on a thermometer reading on when to turn the fans on & off compared to hardwired ones. Many of the plugs can even track electric usage so you know who much $ you are spending on the fans running. Also wondered why on residential system you use the wyes but commercial you just use the taps... could you use the taps on 6" line or is it to reduce the resistance?

[@CeresGreenhouseSolutions]

Thank you for reaching out. To connect with a GAHT™ expert who can answer your question, please contact us at [e-mail]

[@JohnGuest45]

I would install a 10" header down at 3ft at each end of the greenhouse and run 7 x 4" tubes at 2ft and 4ft.(14 in total). The 10" should ideally be smooth bore pvc pipe to keep the losses down. Each 4" tube will have a maximum of 85cfm. The combination of layout and fan should give you at least 40 air changes per hour (1200cfm * 60 / greenhouse air volume). If you have long hot summers i`d recommend installing overhead misting to turbocharge the systems cooling performance.

[@gerardshorticultureculture7579]

Hey I love what you guys are doing. I'm in zone 7 in New Jersey. I am doing a residential greenhouse. In my area I see a lot heaters in hoop houses. Im wondering what is the best to mid range material to allow sunlight to enter. meaning what the exterior should be best , glass or poly-. I will be in touch.

[@CeresGreenhouseSolutions]

It depends on your growing goals, climate, budget and more. We offer both types of glazing but it would be best to speak to a designer to decide on the best material to use for your project. Email us at [e-mail] or fill out a contact form here: ceresgs.com/contact/

[@Grammyhugs1]

Does this give a cooler and warmer sides of the greenhouse?

[@CeresGreenhouseSolutions]

Depending on the size of greenhouse we will install more or less GAHT outlets to make sure that the cool or hot air is evenly dispersed.

[@guermandmitriev7924]

most of the Best Listen.. Get a water tank heated by stove while you cooking, using heated water( glicol mix) While you ground warm later using for over nights. Still need few control systems without using much wood. Wood- water storage radial heat. Sun- panel- battery- fan blow heat( cool time, nights) Wood- smoke- generator power. .. One the grate lately build compost hill heater ;) Can run all winter and produce heat above 50 degrees. Time its over for spoiled ones.

[@muppelmuh134]

I would like to ask about tropical perennial greenhouses where you do plant fruit trees... would the trees not root into the soil battery? humid and warm and because the tubes are perforated the soil would also be airated, perfect. Roots will love it. But would roots not destroy the pipe system over the decades? And would a tight root carpet take away from the soil battery properties? What do you recommend for greenhouses that are supposed to grow tropical trees directly in the ground and that are supposed to last a generation?

[@CeresGreenhouseSolutions]

We can design a GAHT® system to account for root depth. We would love to partner with you to build you a customized setup that would fit your needs. Please contact us at [e-mail] for more information

[@pennylund7626]

This is actually my goal, lemon & orange trees grown in-ground in zone 4b. I too am wondering about the shallow tubes, root systems & longevity.

[@sergey1velev]

Hello. How deep I would need to place each of the two layers, if I want to grow tropical plants in an area with altitude of 1140 meter above sea level? Thank you.

[@CeresGreenhouseSolutions]

Hi, We recommend that the systems layers be placed at 2' and 4' below grade. In theory, the deeper you can place the systems the better, but you need to watch out for areas with high water tables.

[@DianeSchips]

I'm designing a 102'x20' greenhouse. I'm looking at growing warm and cool weather crops in southern Vermont all year. I'm thinking of maintaining different temperatures from one side to the other for warm and cool crops. Would it be better to have one commercial type system, or say three or four residential type systems next to each other?

[@CeresGreenhouseSolutions]

Unfortunately it is very difficult to "partition" a greenhouse into climate sections when its all one large space. You will be able to grow different things, but you won't be able to create specifically "warm" and "cool" areas. If you want to create completely different climates, we recommend you build different units

[@carpenterfamily6198]

12:50 Interesting comments about the temperature of the intake air and how that might effect the efficiency of the heat transfer underground. I would have thought ‘ hotter in ‘ was better, but apparently not necessarily. I would like to better understand this.

[@CeresGreenhouseSolutions]

We have a GAHT® expert on-hand who is more than happy to explain the capabilities of the system more in-depth. Please email [e-mail] with your inquiry and we will get you in touch with him.

[@JohnGuest45]

Heat transfer efficiency depends on maintaining a temperature differential over the full length of the tube. If you have a 20ft tube and the air drops to ground temperature in the first 10ft, the remaining 10ft wont be contributing anything. Using cooler air will compound this as the temperature difference is smaller to begin with. You would be surprised how fast heat is transferred. Most systems use overly long tubes and insufficient flowrates. The inline fans at 12.50 look like they are equipped with 6"- 4" reducers which will have a big impact on the flowrate and the system efficiency. An expert simply wouldnt make this kind of basic error.

[@CeresGreenhouseSolutions]

@@JohnGuest45 If you have questions about the efficacy of the GAHT® system, and would like to talk to our technical expert, please email us at [e-mail]. He will be happy to talk through everything with you.

[@JohnGuest45]

@@CeresGreenhouseSolutions I trust it wont be the same "technical expert" that thought fitting reducers on the fans was a good idea.

[@lmiller4560]

How viable would it be use nonperferated tubing for cooling in sand while using perferated to introguce excess water into the sand to make it more thermally conductive?

[@CeresGreenhouseSolutions]

Thanks for reaching out, to get connected with a GAHT® expert who can answer your specific question, please email [e-mail]

[@radickd2]

The small GAHT system around, 4:00 mark, should have larger feed and cross pipes. Otherwise, it will suffer from low pressure in the heat/cool pipes underground. I wonder if anyone has combined a thermal battery with the ground temperature heating system that Russ Finch is using in Nebraska. Bring in stable temps from way below the frost line and them stabilize it with an earth battery. Anyone know of such an application?

[@justgivemethetruth]

I have no really studied these systems very much because the claims and data are all over the place, but what I have seem from the charts of ground temp is that, yes, the ground is warmer or cooler deeper in the ground, but it is not really that warm in the winter, or cool in the summer. Probably cooler in the summer than it is warm in winter. I think you need a heat-exchanger or something heat pump to concentrate the heat you can pull from the ground

[@CeresGreenhouseSolutions]

Hi Daniel, the graphic shown around minute 4:00 may be a bit deceptive. For smaller systems we use 6" manifolds and 4" "cross pipes." For larger systems, we use up to 18" manifolds.

[@justgivemethetruth]

@@CeresGreenhouseSolutions Curious, is there any thermodynamic studies done on this? I'm just wondering that because as the pipe diameter grows the ratio of the area inside the pipe to the circumference becomes small and smaller, or the surface area of the pipe for heat transfer becomes smaller as compared with the volume of air moving through it so that heat transfer would be less comparatively.

[@CeresGreenhouseSolutions]

@@justgivemethetruth Thank you for your question, if you email us at [e-mail] or call us at [phone] we can connect you with a GAHT® expert who can answer all your questions regarding the efficacy of the system.

[@jimfyffe9543]

Bingo daniel, I have designed a fully insulated earth battery system to actually collect summer heat and store it for winter use. Yes it's possible

[@kevinjmellis]

I live in the far north canada, so I would be very concerned with thawing the perks frost

[@offgridwanabe]

You need to insulate the bottom of the earth battery to avoid that

[@Nimkynene]

You would have to go below the frost line

[@tonychan2504]

In permafrost land. It would be very complex. Dig your thermo battery tubes BELOW the permafrost layer, into the ground where it is warm by earth's mantle. Then insulate the in/out tubes ,so you don't lose heat, or turn your foundation into muskeg I think it would be not feasible in permafrost lands .

[@lorenzopiano7419]

What is the m3 of the pipe in adecuation with the m3 of the construction !? Thanks . Waiting for response ...

[@CeresGreenhouseSolutions]

For more technical questions, please email us at [e-mail], thank you

[@ThirdEyeSwitch]

How about a drainage hose at a low point to pump away moisture collecting to forego slotted pipes and therefore not collect radon?

[@CeresGreenhouseSolutions]

The pipes of a GAHT™ system have small perforations so as water condenses underground, it drains out into the soil. This also helps reduce mold issues, which have not been reported in years of testing.

[@boxelder9167]

I have seen that used in systems for houses.

[@robdrag7762]

hi Bill has you tested for radon gas in the green houses.

[@CeresGreenhouseSolutions]

In areas with high radon levels, it should be taken seriously. However, greenhouses are less dangerous than conventional buildings when it comes to radon. First, you are not in the greenhouse for as much time. Secondly, greenhouses have very high air exchange rates. During much of the year, air (and any radon) will be ventilated outside, and the whole structure will be flushed with fresh air in a matter of minutes. Even if the ventilation system is not on, greenhouses have many more air exchanges than a standard home, mitigating radon build-up. In our tests of GAHT® systems in the Rocky Mountains (an area with high radon levels), the concentration inside the greenhouse was found to be slightly higher than outdoors, but much lower than a dangerous level. By no means is this a comprehensive study, so if concerned, have your soils tested for radon before installing a GAHT® system.

[@robdrag7762]

@@CeresGreenhouseSolutions thanks

[@justgivemethetruth]

Is the pipe buried in regular dirt/soil, or is it in crushed rock or some other medium?

[@CeresGreenhouseSolutions]

We recommend that the systems be back filled with loamy soil for optimal heat transfer.

[@justgivemethetruth]

@@CeresGreenhouseSolutions I am not sure what loamy soil means? Are you saying that you dig out an area, dispose of that dirt, and then backfill the hole with some kind of soil that you must purchase and transport to the hole?

[@CeresGreenhouseSolutions]

@@justgivemethetruth loamy soil is ideal growing soil, it retains water which allows for good heat transfer. In a perfect world, the soil that is already there is loamy enough, and oftentimes it is. But sometimes clients do have to dispose of the soil that is there and get new soil.

[@boxelder9167]

@@justgivemethetruth - clay works well for heat transfer also but gravel is poor because it traps air which insulates.

[@edhewison6119]

If the underground pipes are peforated, what stops the backfill from blocking the holes?

[@CeresGreenhouseSolutions]

Hi Ed, We recommend using perforated and sleeved pipe to prevent the issue that you describe.

[@Jarrett_Hagar]

what about landscaping fabric atop each layer?

[@boxelder9167]

@@Jarrett_Hagar you could wrap the pipe but the socks that they sell for it are ready to go and on in a few minutes.

[@matthewrichie6080]

I'm only 12 minutes into the video, so please ignore this if it is addressed later. Is the fan necessary? I've heard passive greenhouse designers talk about using a height difference for intake and output pipes to create air flow based on the temperature. As you can tell from my lack of terminology, my physics knowledge is lacking.

[@StaleCookies]

I’d say it’s necessary in this case as there is no hot air escaping creating a vacuum of cool air behind it as utilised in earthship building.

[@CeresGreenhouseSolutions]

We have found that fans are necessary for optimal system performance. In theory, a passive approach may work, but using a fan allows for more air to be conditioned by the climate battery.

[@williamdenham8018]

How many BTUs of heat transfer with a typical system? What is the COP?

[@CeresGreenhouseSolutions]

Each system is unique to the local climate and greenhouse. We are happy to estimate the performance of a GAHT® for your unique project. Please contact [e-mail] for more information

[@cymbiline]

Can he GAHT be adapted to cool house attics?

[@CeresGreenhouseSolutions]

To date we have never installed a house GAHT® system. This does not mean it is not possible. We just have not installed one. Before considering this option there are two concerns you should be aware of: 1.Radon 2.Mold Radon can be tested. And even if there is radon, it is more significant to watch the rate at which it accumulates. In the worst-case scenario, if radon is detected the GAHT® system can always be shut off. According to studies that were performed by the University of Minnesota on several GAHT® systems where mold was tested no elevated spores were detected. It is important to keep in mind this is one study, and they were conducted on greenhouses and not homes. When trying to mitigate mold in the home you could use a filtration system with a UV lamp. It is important to look at the ducting system- how to get air through the system. We can help with the design of a new system, but it is harder to work with existing ones. Understanding these precautions is necessary if you decide to try this system on a house. Please consult us at [e-mail] if you are thinking of a house GAHT®.

[@meezee894]

Hi what was the reason for not using non perforated pipe. My water table is high for a lot of the year. Thank you

[@CeresGreenhouseSolutions]

the reason for not using non-perforated piping is so that moisture can escape when it builds up when the GAHT is in cooling mode. If you are interested in learning about a solution to your high water table, please contact [e-mail] and we can put you in touch with a GAHT expert

[@meezee894]

@@CeresGreenhouseSolutions thank you will do

[@smarthomesecurityny]

Have you had any issues with mold in the pipes or a negative effect on air quality?

[@CeresGreenhouseSolutions]

There are no issues with mold because the condensed water is able to drain out of the pipes through the perforations. Also, studies on our GAHT system have shown that the system actually slightly filters the air moving through it.

[@smarthomesecurityny]

@@CeresGreenhouseSolutions thank you for the response 🙂

[@mrpush2532]

'Face change" material for thermal mass? Not sure what your talking about there. Water (best heat capacity per unit mass of any sustance) has about 3x the heat capacity as stone and more so than soil. There can be issues getting the heat into the water however a large subterranean water storage mass is your best bet for maximizing heat capaity. Many "geothermal" systems run pipes into ponds to grab the heat. You need many many more times the weight (and volume)of soil or stone to hold the same amount of heat that water can store. Due to this fact has anyone seen data or design on subterranean water thermal mass?

[@CeresGreenhouseSolutions]

Sorry about the audio, what he actually said was "phase change" and we talk about this material in our blog: ceresgs.com/tips-on-using-water-barrels-in-a-solar-greenhouse/

[@MrKjetil1965]

At 2:11 you say that " this phase change is the key driver of the transfer of heat". Can you please explain how that works. I would have thought that when moist air condenses to water this would release excess heat to the system since the opposite, boiling water to evaporate it requires energy. I've bought your book "the year round solar greenhouse" and I want to implement your system in my greenhouse build but your statement does confuse me. How can you actually get a decreese in temperature in a system that experiences release of energy in a phase change?

[@CeresGreenhouseSolutions]

The soil is absorbing the heat in the moist air, as the soil absorbs the heat, some of the moisture condenses and releases it's energy to the soil. How much moisture condenses will depend on the temperature and relative humidity of the air, and the temperature of the soil.

[@JohnGuest45]

The energy that was used to convert liquid water into water vapour (gas) is released when the air drops to dewpoint inside the tubing. Its important to note that this only happens when the system is being used for cooling. When the system is being used for heating the opposite happens, sensible energy from the thermal mass is used to evaporate water which is returned to the greenhouse as humidity. .

[@dario7888]

great video, only the audio quality is kind of bad

[@Johngaltsghost]

Put a UV-C tube in the outlet and maybe inlet tubes and that should fry any mold/funghi spores

[@CeresGreenhouseSolutions]

Mold and fungi aren't issues with the GAHT™ system since there are perforations in the tubing to allow water to drain to prevent buildup

[@JohnGuest45]

​@@CeresGreenhouseSolutions Perforated drainage tube is usually designed to let water in, not out. Your own video shows the water cannot fully drain from the tubing due to the location of the perforations ,kzbin.info/www/bejne/mqu1mWd9f6mAepo the narrator clearly states water will not collect in the pipes which isnt true.

[@CeresGreenhouseSolutions]

@@JohnGuest45 We have installed GAHT® systems for many many growers and we don't have issues with water buildup in the pipes and or mold/mildew issues from the system. If you'd like to learn more please email [e-mail] to speak to a GAHT® expert.

[@JohnGuest45]

@@CeresGreenhouseSolutions The issue is not with water build up, the issue is that the water trapped in the lower corrugations will be converted into water vapor when the system is used for heating. The webinar doesnt mention the increase in greenhouse humidity...The greenhouse air temperature may be 50F but it could also be in excess of 90% RH, especially during the night which isnt good for plants or the greenhouse structure itself. Take a foot of 4" ads tubing, tip water inside and measure how much remains in the corrugations. Multiply that amount by the total tubing length (in ft) and it will be significant. Convert the volume of water to weight (lbs) and multiply by 1000. Thats the number of btu`s the thermal mass will need to give up in order to convert the water in the corrugations into water vapor.

[@kenchafin9890]

Do you have to use perforated pipe?

[@CeresGreenhouseSolutions]

We recommend it or else you will get moisture buildup in your pipes and this will cause mold and mildew in your system.

[@kenchafin9890]

@@CeresGreenhouseSolutions So you are saying the airflow does more to cause mold than to eliminate it? (because of temp change) I have used fans to dry out basements and other spaces to avoid mold. I just thought the air flow would be a neutralizer.

[@CeresGreenhouseSolutions]

@@kenchafin9890 When your hot greenhouse air is pushed underground by your GAHT® fans and the soil cools it, natural condensation occurs in the pipes. That is why we designed our system to use perforated pipes so the moisture from the condensation can escape the pipes and mold doesn't accrue down there.

[@kenchafin9890]

@@CeresGreenhouseSolutions That does make sense. Also, I was considering running a separate heated Pex line inside the GAHT (with a Summer shut off), for winter use only for those extreme cold spells, What do you think?

[@boxelder9167]

@@kenchafin9890 - I am going to have a separate pipe outside of the structure that runs through a trench filled with mulch to capture the heat of the compost reaction.

[@gregridgeway8790]

This system does look like an excellent environment for fungus and bacteria to thrive.

[@CeresGreenhouseSolutions]

Actually the GAHT® system has been known to filter the air passing through it. Also the pipes are perforated, allowing condensation to drain as the warm air is cooled.

[@BamaCoolDaddy]

@@CeresGreenhouseSolutions I may be out of bounds as I am new to this technology, however if mold, bacteria etc. is of concern couldn't you introduce a positive/negative ion generator to the system. ie; Air Oasis Bi Polar 2400?

[@CeresGreenhouseSolutions]

@@BamaCoolDaddy You could certainly treat the air going into or coming out of a GAHT®. However, we have tested many GAHT® systems and have yet to find one where the air had more particles coming out of it that what had gone in. An increase in particles could be an indication of mold growth.

[@joaquimdafabrica4317]

can you use this GAHT system in a house?

[@CeresGreenhouseSolutions]

To date we have never installed a house GAHT® system. This does not mean it is not possible. We just have not installed one. Before considering this option there are two concerns you should be aware of: Radon Mold Radon can be tested. And even if there is radon, it is more significant to watch the rate at which it accumulates. In the worst case scenario, if radon is detected the GAHT® system can always be shut off. According to studies that were performed by the University of Minnesota on several GAHT® systems where mold was tested no elevated spores were detected. It is important to keep in mind this is one study, and they were conducted on greenhouses and not homes. When trying to mitigate mold in the home you could use a filtration system with a UV lamp. It is important to look at ducting system- how to get air through the system. We can help with the design of a new system, but it is harder to work with existing ones. Understanding these precautions is necessary if you decide to try this system on a house. Please consult us if you are thinking of a house GAHT®.

[@boxelder9167]

Typically they are going from the house to 6 to 8 feet deep at a 45 degree angle then giving the pipe a 2 percent slope for about 150 feet where it can drain into an accessible sump to collect condensation and continues up out of the ground at a 45 degree angle to a height of about 3 feet. They put a filter on the intake pipe. The deeper the pipe the more stable the ground temperature is between seasons. I would check the chart for your area to get the depth that’s most practical.

[@bhumikarijal1956]

How can we know the diameter of pipe for our greenhouse of area 10m*5m and the greenhouse will be 3m underground

[@CeresGreenhouseSolutions]

If you are interested to know information specific to your project, please email us at [e-mail]

[@bhumikarijal1956]

@@CeresGreenhouseSolutions I have done that

[@CeresGreenhouseSolutions]

@@bhumikarijal1956 then I am sure that one of our greenhouse experts are working on a response for you

[@blueside1999]

Positive pressure? Only if the pneumatic pressure is high enough to overcome the hydraulic pressure! Short answer: unlikely, hince the mold issue. No mold should be present in a true positive pressure system. It is likely that the mold spores is collecting outside the perforated pipe and sporing in that safe area. And for the gravel, that is a moisture proof, very dense, thermal mass. A heat/cold battery if you will. My grandpa filled a buried con-x with gravel, top 12' down, plumbed the container to his house, hooked it up to a solar fan, and his house stays at a near constant temp, around 60, year round. 110 outside, 60 inside, -25, still around 60. He added a thermal heater, and for winter it's 70-75°

[@justgivemethetruth]

What is a con-x? I'd love to see a diagram or plan of your grandpa's system

[@jimfyffe9543]

@@justgivemethetruth the ground is a huge thermal Mass one of the best you can come up with it will store Cool air or hot air. To store hot air pipes need to be a little closer and the whole enclosure needs highly insulated especially at the top. solar thermal collectors can heat the soil and be extracted even years later. Special care needs to be taken to keep out moisture and condensation.

[@michaelrowley6069]

I have heard claims that the heat you push into the soil in the summer will be available for use in the winter. That seems unlikely. What is the truth in this matter?

[@CeresGreenhouseSolutions]

The truth in the matter is that it entirely depends on where the greenhouse is located and the amount of solar energy available during the day. This blog might help to explain things a little better: cerescann.com/ceres-gaht-system-versus-the-ceres-ecoloop/

[@l...]

17:40 12 feet = 3.66 M

[@billytodd9929]

How to determine water table

[@maryhornbostel6959]

Dig

[@terrywolsey8741]

can u collect water

[@CeresGreenhouseSolutions]

In what way do you mean?

[@terrywolsey8741]

@@CeresGreenhouseSolutions to use as heat by combining air and water to hold heat?

[@CeresGreenhouseSolutions]

@@terrywolsey8741 we've had growers collect rainwater in barrels to water their plants with but we don't advise that our growers use water barrels as thermal mass in their greenhouse because it takes up a lot of space. We suggest using PCM (phase change material) which comes in sheets that you can simply attach to the north wall of your greenhouse. Check out this blog for more info: ceresgs.com/water-barrels-vs-phase-change-material/

[@melodypearson6920]

How can I get you to design a system for me?

[@CeresGreenhouseSolutions]

Please fill out a contact form here: www.ceresgs.com/contact/ or email us at [e-mail] with your inquiry and a greenhouse designer will get in touch about GAHT® design pricing

[@justgivemethetruth]

How about a simple diagram?

[@michaelrowley6069]

These systems are all horizontal. If money were not an issue, could you design a vertical system. All the condensation would escape at the bottom. If I wanted trees in my greenhouse, I would need a vertical system. Tree roots go deeper than 4 feet.

[@CeresGreenhouseSolutions]

If money were not an issue, we could certainly design a system that was deep enough to avoid interfering with tree roots. However, many dwarf fruit trees have shallow roots (

[@tonythrasher3913]

Looks like a copy of SunnyJohns SHCS

[@JohnGuest45]

Its based on John`s early design. There were lot of breakthroughs made prior to John`s passing in 2011 which led to major design changes which they obviously arent aware of. The same can be said of Jerome Osentowski who worked with John. He is the president of Eco System Design, Inc, and they also use the outdated design..

[@cherrytreepermaculture756]

JohnGuest45 Please elaborate...

[@ThirdEyeSwitch]

Good info, but terrible sound quality.

[@CeresGreenhouseSolutions]

as long as you got something from the content!

[@hotshothomeimprovement]

Pretty awesome, but not very radon safe.

[@CeresGreenhouseSolutions]

A valid concern for sure, and radon levels should also be taken very seriously but greenhouses are less dangerous than conventional buildings when it comes to radon. First, you are not in the greenhouse for as much time. Secondly, greenhouses have very high air exchange rates. During much of the year, air (and any radon) will be ventilated outside, and the whole structure will be flushed with fresh air in a matter of minutes. Even if the ventilation system is not on, greenhouses have many more air exchanges than a standard home, mitigating radon build-up. In our tests of GAHT systems in the Rocky Mountains (an area with high radon levels), the concentration inside the greenhouse was found to be slightly higher than outdoors, but much lower than a dangerous level. By no means is this a comprehensive study, so if concerned, have your soils tested for radon before installing a GAHT system.

[@benandrej1617]

Very important subject, but presentation is all mixed up and confusing and the comentary is, like lost in space and time, just like He does Not know what to say and do... Do it again, and prepare your self better this time.

[@Vothtrucks]

Exactly what I saw here. He scuffs , pauseses, stops , drops his voice to a point where it becomes questionable as to what he was attempting to say.

[@CeresGreenhouseSolutions]

Bill is a GAHT™ expert first and foremost and a presenter second. As you can imagine, there is a lot to cover in the material so naturally, slipups will occur. If you would like to learn more about the system, please contact us at [e-mail]

[@chip63us]

Thank you, does

[@chip63us]

Does the system provide all the heat

[@CeresGreenhouseSolutions]

It depends on the location of the greenhouse and what you're growing. If you live in a colder climate like the midwest or Canada, you're probably going to need additional heating to make sure you maintain a comfortable grow environment for your plants. Here is a blog with more information: cerescann.com/ceres-gaht-system-versus-the-ceres-ecoloop/