Earth Tube short...

I have had these earth tubes running for almost a year and they have kept the place warm all winter and cool in the summer. It was 90 degrees on Saturday and I filmed some temps. I'm still going to release a full video looking at the full years performance, but here is a taste for now.
I have been too busy lately to work on a proper construction video, but I hope to release another one sooner or later.

[@bobjoatmon1993]

So the 8" tube exchanges more heat than the 6"? Wow, that's counter intuitive. I've considered doing earthtubes for the earth sheltered ICF house I'm building into a hillside BUT I'd have to zigzag the tubes, getting 200 linear feet in 100 foot distance downhill. Then there's a ride up the next hill (which is also my property an additional 300 feet) but I'm concerned because the low spot between the hills fills up with water every time it rains. I can just imagine if I ran it up the other hill I would get condensation filling the low spot AND possibly the tubes "floating" up through saturated soil.

[@ForbiddTV]

I might be concerned of any standing water in an earth tube. Also consider accessibility in the event any mold should develop in your pipe. Devise a method that it could be cleaned should the worse happen. That's why I used a pipe large enough on mine to actually get inside and scrub it down if necessary.

[@SimonHomeintheEarth]

Yes, actually, good intuition. I now suspect I was noticing something transient instead of steady state. I was tired and put this video together without reviewing the script. Now that I have... I'll write it out for you here and then pin this comment/correction/explanation. The two tubes have the same fan, so the flow rates are very different and the larger one (with less resistance) brings in more than double the air flow. Also, the larger tube is a double wall (N-12), so its flow rate is better and smoother. So, normally, it is the smaller tube that is pretty consistently two degrees more moderate than the larger one. It has been this way since the first day I turned them on and they have been running solid for a year. In winter the smaller tube is 2 degrees warmer and in summer it is 2 degrees cooler. I chuckle when I see it because I would expect it to be proportionally more moderate (like a percentage), but not 2 degrees no matter what the temp is outside. Then something changed last week... I was going thru my inspection checklist (reading all the codes) and I noticed that Building Code requires me to have these fans on a timer that runs them periodically. I am sure running all the time is better than periodically, but I just needed to pass inspection and figured that running them every other hour would save me a little electricity (the fans are 47 watts each and I have 4 of them, plus the dehumidifier). I set that up last weekend and then forgot all about it. I now suspect that I just happened to have walked in with my camera a moment or two after the fans had turned on. The larger tube probably got its cool air from mid tube up to the sensor and dropped the temp more quickly than the normally more moderating tube. If I let them run to steady state, the smaller one would probably have eventually moderated more. But I saw the 2 degree difference and recognized that as "normal" without noticing that it was reversed. Next time I take a video, I'll check the timer and make sure it has been running for a decent amount of time before filming.

[@SimonHomeintheEarth]

For your design, try to go straight if you can. Sometimes constrained space makes the Zig zag necessary, but don't do it to try and help "mix" the air. All it does is add back pressure (resistance) and reduce flow without increasing thermal mixing. If you want to reduce your flow rate, save the tube and just use a smaller fan to get the same end result with less loss. For your specific situation, I suggest using all your tube on the downhill slope in parallel runs... You would have much less back pressure and no problems with drainage. If the much higher airflow was not moderating the air enough, you could just reduce the fan (or turn it off and go passive) or even restrict the inlet or outlet until you got the performance you wanted. Just spread the parallel runs out as much as you can so they are not all interacting with the same soil, but honestly, my 4 all ended up in the same trench (closer to each other than I would have liked) because the trench was already going in for my septic and I didn't want to pay for additional trenching.

[@bobjoatmon1993]

@@SimonHomeintheEarth The house has a heat chimney (ferocement, with black pigment mixed into the mortar) at the highest point that's the only disruption to the sloped flat roof (R80 and except for the front wall, all that shows above ground) I installed two 6" tubes just under the foundation in the prep work but they are capped off a few feet beyond the house, (for 'later' in the do list) No inspections are required in NE Texas beyond septic in the county so even though I have been building to national code for plumbing, electrical and structure, no one's questioned my engineering / design. On a sunny day, cracking the front door results in a noticable draft as rising air in the chimney pulls air in through the house... So I haven't installed any fans yet. There's no interior walls yet either, I moved in and only the kitchen is finished, bathroom partially done, otherwise I'm 'camping' in the hull of the house.

[@SimonHomeintheEarth]

@@bobjoatmon1993 Yes, I did something similar where I got most of the walls up before I bothered playing with the earth tubes. They just didn't seem like priority at the time. But now that the walls are up and it is hot outside, I am liking the nice cool air.

[@RiDankulous]

This is wonderful! You are a trailblazer!

[@fouroakfarm]

To call this project monumental would be an understatement. Ive followed from the beginning and just wow. Way to stick through on this and awesome to start seeing results

[@jcadult101]

Floor is looking awesome! Just yesterday I was starting to wonder if I'd missed an update, thanks for the post!!

[@Vanillabean321]

This was so informative and very cool to see. Fantastic project.

[@1958indyfan]

Very impressive. My dad used to talk about this back in the 60's. It is a shame he let life get in his way before putting it to use.

[@FrankLadd]

Excellent Short video! Thanks for making it!

[@kschleic9053]

Great to see the progress!

[@springtree2184]

Thank you & good work! Anxiously waiting for the video showing the full years performance.

[@BenKoren]

Great stuff. Thanks for the quick post.

[@mjsmith8655]

Very impressive numbers! Good job as always👍keep it up! Can't wait for your next video!!!

[@luuksta1027]

Thanks for the update! I'm still hoping a bit for a full update on the actual isolation plan. I read your web site, but that seems a bit outdated at the moment (understandebly). Anyways, your project is a huge motivation for me to investigate efficient living, confort by design and smart ways of harnesing energy. I wish you all the best!

[@elliotazus6258]

Same for me also I was thinking of HITE yesterday an we get a 3 minute teaser! God bless and take care Simon and family

[@president2]

love it great job

[@kevinwilliams8662]

Enjoyed the show

[@jasonl3445]

Awesome stuff much love

[@jennetichi9551]

thanks for the update! I am looking forward to your next longer video

[@lightning9279]

Thinking of you today as well. I saw something and made me wonder. That is some crazy free ac. 👍

[@trevor5290]

Very Impressive!

[@noproblem2big337]

Well done Simon...I haven't been watching for a long while, that looks fantastic and well planned, most earth tubes I've seen are way too short...you and the missus have taken up a huge project almost to completion, hats off to you both that is a huge achievement 👌👏👏👏👏👍 I have to mention your parents and the kids are a great help as well!

[@JohnGuest45]

The notion that earth tubes have to be long is counter intuitive. Consider the surface area available for heat exchange of a single 250ft tube is exactly the same as 10x 25ft tubes. The difference is you can move considerably more air through the 10 shorter tubes. If you place temperature sensors at regular intervals along the 250ft tube you will be able to see where the air drops to the ground temperature in the tube and then coasts through the remaining length without losing any more heat. Typically, with a reasonable temperature differential, it will happen in the first 20ft of tube, which means 230ft of tube isnt contributing anything. If you like practical experiments, dig a trench and install a single tube 20ft long and attach a fan with a speed controller to one end. Install several sensors in the trench so you can monitor the ground temperature. Fire up the fan and see if you can get the temperature of the air coming out of the tube to be above the ground temperature. Basically, try to outrun the cooling capacity of the tube by increasing the airflow rate. Dont be surprised if you cant do it. Most video`s show the inlet and outlet temperature and sometimes the inlet and outlet relative humidity, but very few measure the airflow which is absolutely necessary for calculating the system performance. A large in/out temperature difference looks impressive but its meaningless without the flowrate.

[@noproblem2big337]

@@JohnGuest45 not sure if you watched the video, he has 4x250 ft tubes on this side and others on the opposite side of course airflow is very important (I've been in aircon/refrigeration all my working life) and looks like Simon has no airflow restrictions with this setup, and I agree you can also have 40x25 feet tubes and get the same result but you would need a ridiculously large return air fan box to accumulate (and balance airflow between ) 40 large tubes with correct spacing...don't you agree?

[@JohnGuest45]

@@noproblem2big337 The 250ft tubes are a restriction in terms of limiting air flow. At 100cfm you will need a fan capable of delivering 100cfm at 1.75" wc, the velocity would be approx 19.1ft per second and the air would take 13 seconds to travel through the tube. If the air drops to the ground temperature in the first 20ft you are in trouble because you cant just increase the flow rate due to the tube length, doubling the flow to 200cfm would require a fan capable of 200cfm at 7" wc. If you put the same 200cfm through 10x 25ft tubes you`d have 20cfm per tube, a velocity of 3.81ft per second and the air would take 6.5 seconds to travel the length of the tube. The difference is the fan will only be required to deliver the 200cfm at 0.01" wc which is easily done. If you ran 100cfm through each of the ten 25ft tubes you would require a fan capable of 1000cfm at 0.17" wc, again very easy. If you tried to run the same 1000cfm through a single 250ft tube you`d need fan are capable of 1000cfm at 175" wc (thats almost 6.5psi !! ) which just isnt possible. Note the tube surface area of a single 250ft and 10 x 25ft tubes have exactly the same heat exchange potential, the difference is how much air you can run.

[@dansv1]

I was looking for Quonset hut home videos and watched yours. I thought: that’s cool, a family put up one by themselves. After binge watching 95 more videos, I’m blown away at the scope of the build.

[@SimonHomeintheEarth]

Well thanks for joining us on the ride...

[@DNL82]

That's pretty cool 😎 👍

[@DanLee1969]

I'm interested to know more about this. More videos would be great. But yours was the only coherent one that I've watched out of like 20.

[@samiam7]

How weird is this. I just was thinking you haven't posted a video in a while and bam! Here you are

[@SimonHomeintheEarth]

Yup, I think about it often, but just have not been able to find the time for KZbin lately. I figured a little update would be better than nothing.

[@samiam7]

@@SimonHomeintheEarth oh absolutely!

[@kschleic9053]

@@SimonHomeintheEarth the short format works well as the finishing projects become smaller and more detail oriented!

[@bigbraincontent]

Love to see it

[@winstonzeb2842]

Sooo freakin cool!

[@michaelcatalanottohandyman]

Well done

[@toddincabo]

kick ass man!

[@ChristopherSloane]

Love to have this in Florida but it would not work for the HOA and the humidity here is 90% ish all the time in the summer, Given the right property and the like I wonder if it would work.

[@mfrederickson1]

Cool. How's the book coming? nudge, nudge.

[@ryanbarr4910]

Fantastic! Thank you for showing your working set-up! Materials 1) Aprilaire Dehumidifier 2) double-walled HDPE pipes (4"x2 & 6"x2) 3) AC Infinity inline duct fans x 4 4) galvanized steel lath 5) furnace filters Design *You slope the 4 pipes 250' up toward the house and make pipe fittings soil tight but not water-tight to allow condensation to drain. *You have a machine room below grade. From there you pull air into the dehumidifier and then push air into the home. *Galvanized steel lath at earth tube entry (& eventually furnace filters?) Did I get that right? Did I leave anything out? How many sqft is your home?

[@SimonHomeintheEarth]

The double walled pipes are actually N-12 Dual wall pipe. 8 inch diameter with soil tight connections. The six inch pipes are actually just regular single wall corrugated tubes (drain tile) like you would get from home depot. I actually put those in as drain tile for the house, but instead of a lasso shape, I have two pipes coming up the hill and around each side of the house. They meet on the back side of the mechanical room and come up and in. I was experimenting with dual use and various different sizes. I do have some 4 inch and even a 1 inch pipe, but those are not currently hooked up. I now have the furnace filters and screen in place. You can find pics of that on our facebook page. The house is doing great in the winter and I am over due for another video update.

[@ForbiddTV]

Nice to see some earth tube numbers, it was hot today. I gathered water from my spring for my solar shower today. 90 degrees outside, spring water was 45, the sun was able to take the water to 140!

[@SimonASNG]

Yea, I wish I had solar hot water heating. That was in the original plan (vacuum tube setup), but was set aside for now until we sort out the critical stuff.

[@ForbiddTV]

@@SimonASNG Since my place isn't anywhere near as long as yours is, my solar shower is simply a sort of black bag I lay in the sun, then hoist it with pulleys from a tree limb, so can be done with little expense until something better is installed. Showering in the open woods is an experience!

[@SimonHomeintheEarth]

I mainly want mine (I switched to the proper youtube account) for use in the winter as a heating source, which is why I need the fancy vacuum tube stuff. My father uses those black panel heaters for his pool and they work very well in summer.

[@barthanes1]

I have considered using earth tubes for home cooling as well as a water source. Place a catch basin at the intake to collect the condensate and make the pipe smooth and continuous. I'm not sure what kind of volume it would produce though.

[@SimonHomeintheEarth]

I am sure the volume of water produced would vary during the year. In the spring, when the walls are cooler and the air is very humid, we get a lot of condensation. In the winter, the opposite is true (warmer walls and low humidity in the air), and we get none. Ironically, the more you need water (for instance, if you are in a desert), the less you will get from such a system.

[@JohnGuest45]

@@SimonHomeintheEarth You can estimate the potential quantity of condensate using psychrometrics, all you need to know is your height above sea level, the airflow rate in cfm, the inlet/outlet temperatures and RH percentages. You can use the same method to estimate the heat transfer and, if you measure the power consumed by the fan(s)), the system efficiency too.

[@uendarkarplips7263]

More videos please

[@jjonesindustries]

amazing!! can you please share what brand the temp & humidity meters are?

[@jfbaro2]

Please, how to avoid mold or any other “bad thing” to live in the tube? Thanks for sharing!!

[@SimonHomeintheEarth]

Mold needs a bunch of stuff to live. I try not to give them any of it. I go into this in great detail on my website if you want to go check that out. www.homeintheearth.com/tech_notes/earth-tubes/earth-tube-concerns/

[@brianmurphy5350]

Question. When can you use thin walled pvc to move air underground compare to perforated pipe? Would you possibly get mold if you use solid pipe?

[@SimonHomeintheEarth]

I also used solid pipe. The HDPE dual wall pipe is the best option. It is smooth and solid on the inside, but thin enough for rapid heat transfer. Nothing can grow on it. Water can exit thru the soil tight joints. It is tough and flexible and relatively light. Thin walled pvc (sewer pipe) would also work. But it is not as tough or strong as the hdpe and doesn't economically come in larger diameter sizes (such as 8 inches).

[@jfbaro2]

Amazing! I am in Brazil, please how can I get more information in this technology so that I can have this installed in my house (DYI). Thanks

[@SimonHomeintheEarth]

I think I found another comment by you, but just incase that was someone else... I recommend my web page. I put a lot of my research up there before I got going. I'll write a book about it eventually, but for now... www.homeintheearth.com/tech_notes/earth-tubes/earth-tube-concerns/

[@Bonecarpenter.]

So the humidity would cause pools of water to form in the tunnels that might stagnate potentially? If it does how does one remove the water out the tunnels safely?

[@MartyHuie]

Just finding your page, and will be building a home at 4000 feet in North Carolina right on the Tennessee line. Wanting to put in earth tubes to supply the air for my ERV, the question I have is concerning mold and mildew growing on the inside of the tubes with the humidity is high as you've indicated in the temperature using the humidity mold growth chart mold would be growing have you experience that I'm wondering if mold would grow with air movement like it does inside the tubes so I'm hoping your answer is no mold is growing :)

[@SimonHomeintheEarth]

No mold here at all. I think mold needs a few key things to grow, water, air and food are the primaries. The easiest one to prevent is a food source. I used smooth wall HDPE pipe, so the mold has very little chance of finding a good home. The water drains out of the tubes quickly. Can't prevent the air, but the air is flowing constantly (keeps flowing even when the fans are off), so it never gets stagnant.

[@MartyHuie]

@@SimonHomeintheEarth absolutely thank you for your reply. Sorry it's taking me so long to come back. Agree and I'm hoping that everything I'm putting in. I won't have mold either. Glad you don't have mold. I think there's enough dry days are partially dry days. That mold will not grow inside my tube.

[@felixspiess]

great project! I have similar Earth Tubes installed in my house (Southern Brazil, mostly hot climate, only needed for cooling, 4x6in tubes, 50m long, coming downhill to the house). Now I need to figure out how to increase air flow: Should I install a solar collector (solar chimney) on the roof, or install a fan in the incoming Earth Tube? I see you have several fans with about 50W each. Have you ever measured the air temperature increase after vs before the fans?

[@SimonHomeintheEarth]

Yes, I measure almost no temperature difference on either side of the fan (it is low wattage relative to the flow volume). I have done tests where I turn off the solar chimney and it makes a significant difference, especially on hot days or windy days. But the fan makes more difference. They work even better together. I have also had days when the power is out and it is nice to know that I don't need to rely on the fans.

[@felixspiess]

@@SimonHomeintheEarth thanks for the explanation. So... fan + solar chimney in combination. Will try to do the same on my project.

[@AKDanMusicMan]

In the summer, are the thermostats triggering fans to push the cooler air to the floor registers? Do the radiant systems run cool water through the floors in the summer to help cool the space?

[@SimonHomeintheEarth]

I have the fans turn on for half of every hour just for the fresh air. I do have a temp controlled fan that sucks hot air down from the skylights and dumps that in the basement in winter and sends it op to the solar chimney in summer. And yes, in the summer, I open up a valve so that well water is drawn in thru the floor tubes before going to the hot water heater. This cools down the floors and warms up the water.

[@jumptodestiny]

Can you share details of entire project ?

[@NormanStansfield1]

This is really impressive at 55 deg F when it is 90+deg F outside. Do you know what the ground temperature is in the summer or the temp in the earth tubes in the ground? My local ground water averages about 72 deg F in a higher humidity are in FL. I wonder if I can get anywhere near 55 deg F if I did earth tubes??. Thanks.

[@SimonHomeintheEarth]

No, your lowest possible is your ground water temp. In Florida, that is usually about 70 degrees or so. Another way to think of it is that it is your average annual temp. Then go a little higher than that due to losses in the system, transfer problems, the ground being affected by the tube, etc. My ground water temp in Michigan is 51 to 55. But 70 is still much better than your air temp outside. So you'll still get some significant benefit, especially during the day when the sun is hottest.

[@M3rVsT4H]

I'm curious to know if you have any concerns about mold growing in the tubes as a result of the condensation down there? Also the house is really coming along.. Getting some final coverings on surfaces must feel so good.

[@ForbiddTV]

Yes, and I was wondering why we don't see a lot of water staining the concrete or puddling in the bottom of the entry box.

[@SimonHomeintheEarth]

Nope, no mold. Mold needs a few key elements to survive and make sure to withhold a couple. If the tube were made of concrete, there might probably be a problem.

[@SimonHomeintheEarth]

@@ForbiddTV Yea, I think I already answered this one for you... The bells on the ends of the 20 ft pipe sections all open downward. The inside is mostly smooth, but the joints are grooved and catch the water. The connections are soil tight, but they are not water tight, so the water leaks out. I tested this before burial by putting a garden hose in the top end and even at a full flow rate, almost no water came out at the bottom of the hill because there were 13 joints leaking along the way. I'll have to find that video and remember to explain this when I do the "all seasons" earth tube video.

[@M3rVsT4H]

@@SimonHomeintheEarth Thanks for the followup info. I'm making plans to get one in the ground asap and give it a good test this coming hot season down under.

[@coasterkat4432]

Do you have any instructional videos for us DIYers? I really want to have the air tubes but have no idea of what I need or how to do mine like this. TYSM for sharing!

[@SimonHomeintheEarth]

Start by checking out my web page. I have a bunch of good design info on there about earth tubes. www.homeintheearth.com/tech_notes/earth-tubes/

[@keimo2007]

Any updates... thanks!

[@ryanbrown982]

I'm envious. I have a gas pipeline on my property, so I'm limited on how long I can bury tubes. I'll get 100ish feet on average. Mine will also only be makeup air for open windows and exhaust fans. Your setup is far more impressive.

[@SimonHomeintheEarth]

If you can't go longer, just run more in parallel and then use a smaller fan or share a fan between them. The tube length doesn't all need to be in serial if you just run it slower. 100 feet is enough.

[@ryanbrown982]

@@SimonHomeintheEarth Yeah, I'm planning to run 2 parallel 8 inch runs. I'm not going to worry about a fan initially; hopefully convection currents will pull through enough air to be useful. If necessary, I can always install a fan after the fact. Do you have any filtration on the air coming in?

[@SimonHomeintheEarth]

@@ryanbrown982 On the inside end, there is a proper commercial filter in the dehumidifier. I plan to put furnace filters on the outside end also. So far, I have not noticed any dust or pollen being carried in, but the fan blades are getting dirty, so maybe that is the evidence.

[@ryanbrown982]

@@SimonHomeintheEarth Good to know. I'm actually off to pay for 250' of 8" pipe this afternoon to bury for a single inlet line to an ERV (possibly with a dehumidifier in line if necessary). I don't expect to rely on it for 100% of our cooling needs (I'm in TX, so cooling is more of a concern than heating), but every little bit helps. Always enjoy seeing your updates. Looking forward to the next one.

[@langeheinrich9619]

simon everything ok with you and family long time no see greetings belgium

[@SimonASNG]

Yup, just very busy with work and finalizing the home so we can move in. No time for editing videos although I did spend most of Sunday afternoon converting time lapse photos into video clips because my computer was running out of storage space. I'll get back to it sooner or later.

[@jasonmushersee]

recommend aluminum door screen over that mesh

[@SimonASNG]

Yup, I have rolls of the stuff. I plan to build a frame with treated wood that will hold the screen and have slots for standard size furnace filters. The lath was more urgent because we didn't want to risk critters getting in and blocking the ends, but we haven't actually seen any insects or even pollen making it all the way thru the tubes.

[@chaseme9860]

You should have just used the earth tubes to cool an air-to-air variable rate inverter A/C condenser and air handler in this room instead of using a constant on/off/on inefficient dehumidifier. This will keep the outdoor humidity from even entering the conditioned space in the first place because the only air being conditioned is indoor air. You will use far less energy this way. You also can't use "tables" to tell what your humidity is. You need to take a wet-bulb measurement of the actual room.

[@SimonHomeintheEarth]

At some point in the process, code requires me to bring in fresh air. Several air changes per hour actually. I can't just recycle the internal air and cool it with a heat exchanger, I actually need to bring in the fresh air. That air will have moisture in it. At the moment, my earth tubes have cool walls and squeeze out most of the moisture. By definition, that means they enter at 100% humidity for their given temperature. As for the tables, I was just giving an idea of how the humidity drops when the air heats up as it goes upstairs. That is what the tables are for. I also have several humidity sensors around the house to monitor that directly. I don't measure my humidity upstairs by the tables.

[@fintan3563]

12/5/21 - Hi Simon: You haven’t posted in six months. I’d love to see your progress. I hope all is well!

[@SimonHomeintheEarth]

Yup, I've been busy. But my wife wanted a quiet evening without any drilling, so I am putting together an update on the earth tubes right now. ;)

[@TheMidnightModder]

How much has this house cost you so far?

[@mreugenemendoza]

I'd like to learn more about earth tubes. Saw them before on earthships. I live on a tropical country (humidity 60-80%), near a lakeshore, Can you point me on where can i start? Thanks

[@SimonHomeintheEarth]

As far as I know, my own website has the most comprehensive coverage of the topic, but I have not being trying to research it for a few years (since I figured mine out). If you find a better website, let me know and I'll link to it. www.homeintheearth.com/tech_notes/earth-tubes/

[@mreugenemendoza]

Nice! These are gold! ^^

[@rafavillasboas]

What about the water inside the tubes due to condensation? Does your system has some kind of drainage?

[@SimonHomeintheEarth]

Yea, it slopes down to daylight at the bottom end. But even so, very little water gets down there. The 8 inch tubes are double wall HDPE pipes, but they only have "soil tight" connections every 20 ft and the condensate dribbles out through those. The 6 inch tubes are single wall, corrugated and perforated pipes. Any condensate just leaks out and drains away thru the perforations.

[@hewusy]

What guidelines can you share for tube depth and length?

[@SimonHomeintheEarth]

Generally, go as deep as you can easily afford. 20 ft would be ideal, but is usually much too expensive, so if you can get a digger that does an 8ft trench, do that. If you can only get a 6ft trench for a reasonable amount, then do that. Length is also a bit related to how much property you have, etc. I used 8 inch diameter tubes and 6 inch diameter tubes and 250 ft was plenty. I never ran out of temp exchange all season. The 8 inch ones are double wall and don't moderate quite as well, but let in twice the flow and I wanted to test the smooth wall design just incase I ever needed to clean it. The 6 inch ones are single wall, corrugated and perforated (I wanted to test drainage, etc.) and they moderate a bit better and cost less, but have half the air flow using the same fan. I also have some 75 ft length tubes and they don't hold the temp nearly as well, but the air flows are greater (I have those closed off because the other ones provided more than I needed anyway). Maybe ideal is somewhere between. There are lots of factors at play.

[@jayytee8062]

Have you measured any radon gas increase??

[@Mrcaffinebean]

You missed your chance for a legit click bait title “cooling my home with no AC!” or something similar. Looking forward to seeing more!

[@SimonHomeintheEarth]

Yea, I need to work on the clickbaity stuff. How about, "How did this guy dig a hole and find unlimited free air conditioning?"

[@Mrcaffinebean]

@@SimonHomeintheEarth haha their you go! You can still change it and rack in the views! Normally I hate such titles but in this case it’s legit bait, not click bait! Looking forward to your next video buddy! The home looks BEAUTIFUL!

[@cameronwhite9286]

Updates?

[@MrRerod]

What do you mean by "kept the place warm all winter"? 50 degree air isn't warm, and likely was cooler in the winter.. I could understand cooling and warming a air cooled condenser of a mini split.. But introducing this wet air to the home in summer requires allot of energy to dehumidify. And the potential for mold , living under ground , and drawing air through earth tubes is to high for me.. The only way for it to be safe is if it was all down hill. And even then, I would only supply earth tube air to a condenser or HRV intake.

[@SimonHomeintheEarth]

Funny that your name is "colder"... Yea, 50 isn't warm, but it is very warm compared to the -20 that is outside. So we get the first 70 degrees for free and only need to warm it 18 more. (actually, by the time winter rolls around, the ground has warmed and the income temp is closer to 56 or 58, but anyway... ) Passive solar can handle the remainder needed on its own on any sunny days. On cloudy days, our bodies, cooking, showers, etc. make up most of that difference and the heater rarely turns on. I did give up on the dehumidifier... Mainly just because it was heating up the air a few degrees in summer and it was a bit too big for the job (you saw how quickly it dropped the humidity). Now I run the incoming air over a small 12k mini-spit ac unit. That pulls out all the moisture in summer and dumps any excess heat outside. I could use it in reverse in the winter, but I just turned it off because we didn't need it.

[@MrRerod]

@@SimonHomeintheEarth but when you heat to gain the last 20 degrees, you will lose allot of that heat outside in the earth tube soil. Your heating the earth. In the summer the tubes would introduce a huge amount of humidity.

[@victorpistone1073]

Why not recirculate the air from the house?

[@SimonHomeintheEarth]

Fresh air is a good thing. We do some recirculation, for instance, we pull the warm air from the top of the skylights down to the basement in the winter and that goes around again. But eventually, we kick it out. The trick here is to do it in a controlled way.

[@nick418]

Why don't you upload anymore?

[@paulpierce2051]

So 250’ of earth tube is adequate to dissipate atmospheric heat into the ground.

[@SimonHomeintheEarth]

Yea, it worked well. I was worried about going too long because you eventually can't move air thru the tube, but 250 is fine with both the 8 inch smooth wall pipe and the 6 inch corrugated, although the 8 inch pipe gives about double the volume flow for the same fan.

[@garyofnyc]

In the name of the Allfather and Freya, where are the VIDEOS!?!?

[@SimonHomeintheEarth]

LOL. Sorry, I have been busy. I haven't even come in to check the comments for a few months. In the mean time, you can see more up to date progress on the FB page. Its not as fun as videos, but its something. facebook.com/HomeintheEarth

[@pacificdynamicbuilders4380]

Too cold inside!

[@SimonHomeintheEarth]

Yea, it feels comfortable when we are working, but its a bit chilly for just sitting around. Once we are living there, we will bring the inside temperature up a bit and the earth will hold that too... At least in theory.

[@jam206AR]

Have u measured radon yet?

[@SimonHomeintheEarth]

Radon builds up because you don't have good ventilation. This is the opposite of that. So no radon problems here.

[@jam206AR]

@@SimonHomeintheEarth so u haven’t measured?

[@scubasteve7946]

Late, but it's not pulling air from underground. It's pulling fresh air from outside. Lookup how radon can build up in stagnant houses from the soil to understand. The method here will not be a problem for that.