A Foundation I've NEVER Seen!
HTML-код
- Опубликовано: 30 май 2022
- LEGALETT: www.legalett.ca/index.html
TRUEWERK + BUILD GEAR:
truewerk.com/pages/buildshow
Subscribe and follow my Podcast on Apple or Spotify!
Apple: apple.co/32AOwgU
Spotify: spoti.fi/3FXNg4X
Sign up for our twice-weekly newsletter:
buildshownetwork.com/newsletter
To sponsor a video or advertise with us visit:
www.buildproductions.com
Want to learn more about building? buildshownetwork.com/
Build Show Network on Instagram: / thebuildshow
Huge thanks to our Show sponsors Builders FirstSource, Polywall, Huber, Prosoco, Rockwool & Viewrail for helping to make these videos possible! These are all trusted companies that Matt has worked with for years and trusts their products in the homes he builds. We would highly encourage you to check out their websites for more info.
www.bldr.com/
www.Poly-Wall.com
www.Huberwood.com
www.Prosoco.com
www.Viewrail.com
www.Rockwool.com
I have lived with a Legalett foundation for 20 years, and not only is it lovely gentle heat, it is super energy efficient too.
In 20 years I have only replaced the fan motor once and an electronic module once.
A superior product.
I live in an old tenements block of sand stone .. called a room and kitchen here... At my age I am selling this and looking for land to adopt such concept... Thom in Scotland.
Is the heater accessible from the inside? Do they ever go bad or burn out? How do you repair it if it's embedded in the concrete foundation?
@@Salanan it looks like there is an access point that would be in a mechanical room. So it would be a metal door in the floor.
Yes but that poor confused hamster has been trapped in your tube system for 20 years.
@@Salanan Apparently there's an access hatch in the box with the heater. Looking at it this would probably be flush with the poured concrete. So you would then lay your floor above it in a way to keep the hatch accessbile. No problem.
It's basically a Roman Hypocaust. Cool new version, but this is a modification of how Romans heated buildings as they moved north into places like England. You can see remains of the Roman ones in Bath. Very cool that it's being used again.
This is how they do it in the forbidden city in the winter...without modern insulation system
That's what I was going to say.
I thought "Ondol", it's similar enough to Hypocaust, just Korean...
I worked on a house on South Side of Pittsburgh that an Old Chinese man built that had this same system in foundation..... It used old cork wood from Ice houses that he demolished & low voltage circulation fans and kept the house @ 70'F..... All Summer..... Was built back in 64' was brilliantly engineered..... I was truly humbled.
Mexica; or commonly known as the Aztec also had pipe system to create insulation, but utilized water; not air like this amazing idea. The water flowing also kept the homes cool in the summer but I figure you can accomplish the same with this if you blow cold air. 👍🏽
Comment section FAQ
Q: Isn't this just a Hypocaust / Ondol?
A: No, these are closed loops. Hypocausts / ondol are horizontal chimney extensions. Closed loops require no maintenance or cleaning and are much more efficient.
Q: But isn't air a terrible heat conductor? Wouldn't water be better?
A: Air is ~good enough~ (esp with the larger pipe diameter) and doesn't have the added complexity of pumps, nor the danger of water damage in case of leaks. It also runs at a lower pressure and doesn't freeze. Why overcomplicate things?
Q: Why not just bury underfloor wires / heating pads?
A: You could, but if a foundation cracks and breaks the wire your entire heating system is kaput. With air pipes a leak is less likely, non-catastrophic, and easily patchable.
Q: Why would you bury the furnace in concrete? What about repairs?
A: It's not buried, just recessed. The boxes have hatches which are level with the poured floor. They contain a resistive heating element and a fan.
Q: What happens when I need a part and the company is out of business?
A: They've been in business for 60+ years. Also the parts are ~extremely~ common (electric element, circulation fan).
Q: Can this be paired with solar heating / heat pumps / other forms of heat?
A: Probably? Legalett have done custom things for people before. Ask them!
Q: Isn't this how Earthships are cooled?
A: No, that's completely different. Also a completely different Mike Reynolds.
Q: Why not seal the pipes & fill them with water so they don't float, then drain and dry them out after the concrete sets?
A: It's not necessary.
Q: What about mould?
A: It's a heated, closed system with virtually no moisture. Mould is not an issue.
Q: Shouldn't the pipes be ?
A: PVC works well enough.
Q: Won't the foam be crushed by my massive house? Won't my house blow away in the wind?
A: No and No.
Q: Why not just build a completely different way that I think is better?
A: He chose this way. You do you.
Q: This will never work!
A: This does work, and has for 60+ years in many, many homes. Also that's not a question.
Wow!. This is really helpful. The kind of answer i was looking for. Thank you very much. :)
You are the best comment on this video
I remember back in 1980s when I was a kid my grandmother's house in S.Korea has heated foundation heat warms the floor from the kitchen stove and another fire place located other end of the house on the outside. It's an old house so heat wasn't evenly heated and some place was much hotter than the other. So she always left food containers above where heated location to keep the food warm. What a memory!
Ondol floor, Korean brilliance. I am building one in my off grid cabin.
As a few have mentioned it, here is a YT vid of this being constructed in a Korean house.
ruclips.net/video/bdxzTMrbedg/видео.html
Yep, far easier and more efficient than what this guy did. Does not even take much metal to make work. Most efficient home you can build is a 15 foot deep hole with a house in it. But that is not legal due to building codes that require everything to be done the exact same way as everything else, even if that way is dangerous and inefficient.
Ben franklin had patents on wood stoves similar to what you described.
That is a cool memory...
It humanizes and contextualizes the experience of an ondol floor.
We usually get so wrapped up in the technical, it's easy to lose track of the human experience component.
Thanks for sharing!
I have an uncle who lives in Nova Scotia. He has a similar system only the ducting isn't routed all through his floor - it is routed through concrete that acts as thermal storage though. There is no electric furnace in the piping but the air circulation pulls warm air slowly through the ducting and the heat gets stored in the concrete. As the sun goes down the heat in the concrete gradually migrates from the concrete into the air passing through the ducts to warm the living space. In the winter the sun shines in the windows but in the summer, the sun is high enough that the roof overhang shades the sun and they don't get direct sunlight into the house. It is really well planned and the indirect light is amazing as the front of the house has lots of windows but the overhang keeps those direct rays out in the summer and they shine right in during winter. The outer walls of the house are double walls. A shell, then an air space and then the outer walls of the living space. He's a pretty smart guy.
That double shell of walls is the best possible system for super cold or super hot climates. The only thing better would be a vacuum rather than insulation like a Thermos, which would be astronomically expensive to do house size.
@@BEdwardStover vacuum panels are expensive , but can be very cost effective in high land cost multiplexes situations . In Europe they started using them around 2006 .......Have worked with this floor system but also had huge solar wall integrated with it . The biggest problems comes down to the programing of the controllers for most . The system has six set points . It's a lot of math for the set points
that's awesome. loved hearing about guys who are ahead of their time and have confidence in their abilities and understanding.
Lots of good builders of efficient housing in Nova Scotia. Historically fuel is quite expensive including wood which is of far more use for other things.
Hey Smorg, I’m also in NS and have recently been looking at this type of system. Any chance you’d be willing to connect me with your uncle?
Legalett has been making these Frost Protected Shallow Foundations since 1970`s, all over northern europe and north america. They design all the FPSF with climate, soil type, weight loads and heat loads. I searched before and couldn`t find any failures. It`s by far the least expensive foundation, most DIY friendly and high performance. For those reasons, I be choosing FPSF for my future off grid solar passive house. Kinda surprised Matt never heard of them before as it seems right up his alley.
@Mur Doc Just an fyi---Frank Lloyd Wright was doing these long before Legalett.
@@johnstrawb3521 Just an fyi---the Romans and Koreans were doing these long before Frank Lloyd Wright.
Off grid solar passive house? In what latitude? Above 40 degrees you will need 2 MW of batteries for a winter season (200K+ $). Believe me - i live in a passive house (but not autonomous) - forget about off grid, autonomy, "freedom", etc...In my country you can store our produced energy in electric grid at a very cheap price (0.04 c/kwh) or you can give 30% of produced energy to a local electricity provider and store rest for free (I choose this option), but still house has to be connected. My house uses less energy, than produces (water, sewer cleaning included - so theoretically it is passive) but from November till March i need about 2MW of power and solar power plant produces cat's tears. At this time of the year i use stored (in summer moths) energy from the grid, but if i hadn't such capability it would be the end of all passiveness :). Yes i live for a 0 annual bill (except internet), but it is NOT full autonomy :)
p.s. house's coefficient of tightness 0.10, insulation of walls 12 inches, floor 16' roof 22', special windows and doors with 3 glasses, 2 membranes, recuperation system, heat pump etc...etc.. and still it is almost impossible to store such amount of energy in batteries, which is needed for winter months. Better forget that idea, at least your'e living in Africa or no need for heating all year round. Good luck :)
@@MFrrFrr I just finished my own off grid passive smart house at 9500ft above sea level in colorado. I have 20kW of solar on the roof facing TRUE south on a 12/12 roof pitch and 90kWh worth of batteries. Ill have absolutely no issues through winter and I have all the modern tech. Induction cooktop, heat pump water heater, washer and heat pump dryer and everything else a modern home needs, including ev charging.
@@mattbrew11 I'm not arguing, but i'm surprised how is that possible? Maybe (in your location) you have 320 sunny days out of 365/year in high altitudes? Maybe your location is not so Northern? Or you have other heating solution for your house? (geothermal, wood stove, etc.)? Living in my conditions (by this time) ~3 years (3 winters) - solar power plant in winter months produces 0 energy for weeks (even months) under heavy snow coverage, and I need ~700 kwh of power every month from November till March, and i wonder how 90 kwh battery could save me :) ? It could save me for a 4 days, but then if sun don't come up - i'm dead, and it doesn't from November till March :)
Matt, the Romans and ancient Chinese used this over 2,000 years ago along with Koreans, Japanese, Hindi, and many other cultures in cold climates.
Its used in Korea to this very day, super efficient.
wow, they had pvc pipe 2000 years ago
It took 2000 years, but apparently we’ve “invented” hypocausts. Again. But I’m not dismissing the tech-a good idea is a good idea. What I’m proud to see is taking a good, proven concept like hypocausts married to modern tech & materials. Best of both worlds.
Native Americans around the Great Lakes built long houses with ducted floor heating.
@@paulslevinsky580 so did the Romans...
It's still done in Korea only that they don't use pipes and electricity, they use clay ducts and heat them with a traditional wood heated oven that is on one side of the house. The oven is on one side of the house wir the fireplace deeper than the floor and the chimney on the opposite side of the house. The warm air goes through the area under the house and heats the floor before it goes through the chimney. No need for any fan to move the warm air. The system is called Ondol, Hangul or Gudeul. There is even a version of it that heats only a (stone)bed. These beds are called dol bed and nearly 50% Koreans above 40yo use one.
I think in the west you could use the same architecture with any available heat source like coal, gas, electricity, etc. with no danger of bursting pipes.
exactly what i thought
yeah yeah you guys : ) but this is about modern technology (i.e. foam, pvc pipes, electric heat)
I designed and built a home near Palmer Alaska some 15 years ago using 1/2" PEX line to run water through my 4" monolithic concrete slab, which was fed by a 40-gallon natural gas hot water heater and a recirculating pump. Throughout the coldest months of the winter our gas bill was under $50 per month. The entire heating system cost under $1,000.
Were you warm without grizzly furs?
I heated a 50x120 building 26’ tall ceilings with a similar setup. It would maintain 73 degrees and draw roughly 30 amps when it 0F out.
Radiant floors are amazing for cold climates if you have a consistent and reliable method for heating the water
Sounds like a good idea! Being efficient is a benefit we all look for. Air or hydronic? Which can be better? Air won't freeze and break concrete, but how well does it heat the concrete?
@@mikemcgown6362 warm water will deliver more heat and resist temperature change more effectively. I have seen systems in far north climates that circulate ethylene glycol instead of water in order to prevent freeze damage should the system fail. It takes less energy to change the temperature of air than water (specific heat) which means more energy to come up to temp but also cannot deliver as much energy (heat) into the concrete. Would be great to see a direct comparison of energy demands to maintain the slab temp and associated room temp between air vs water.
My parents built a house that has independent heat/ac in each room.... when you walk in next to the light switch is a digital thermostat and you can pick exactly what temperature you want each room - heated floors and a slim wall mount a/c up near the ceiling- it’s great.
The old romans in Italy used air heated floors like 2000 years ago. Called Hypocaust. Very cool re discovered technology.
Also Koreans
Y’all are a waste of time! lol
A ground sourced heat pump would be an interesting upgrade to this system.
Excellent idea from Legalett. Since attic space often has an overflow of heat, what about redirecting that heat with a small 4-inch duct fan directing the air down into that sub-system of air ducts? Perhaps a way to cool the floors in summer with the reverse, and easy to make the fans run on solar panels.
It reminds me of a modern take on the traditional Korean Ondol floor heating used in Korea. Of course it is much safer since in the traditional Korean system it was essentially a chimney that ran under the floor and any leaks of Carbon Monoxide was often fatal.
It's pretty cool to see some of these ancient technologies put back into use.
Similar concept to "earth-tubes" you dig trenches under ground horizontally, below frost line-solar gain, run pvc tubes and backfill, lay a thermal barrier and complete backfilling, then I've use that geo-tempered air to push towards my A2A heat-pump which increases its COP dramatically (ie instead of HP tempering 35c outside hot air to deliver 20c inside, the earth-tubes do the heavy lifting and bring the 35c outside air to the inlet of the HP down to 22c or 25c at most, making the energy the HP uses to deliver 20c output way easier, consuming less and delivering the same output indoors, in the winter it works the same way, by tempering the extreme cold, to a more moderate temperature at HP inlet, ie. -30c outside, is elevated to -5c or +5/8c or better, making the HP more efficient to deliver 22c indoors ). Very effective and cost efficient. You can also repurpose/up-cycle an old SE boiler to barely sip propane during the nights, by running hydronics through your evacuated tube PV-T and passing that through the boiler (or better yet hot water tank as storage), during the day those roof mounted PV-T will easily output +55c to +65c or better, hot water, which you store in the thermal mass of concrete which will hold it 10-14hrs+, and at night if very cold, you use boiler (or stored water in hot water tanks) with propane to top-up the slow release of heat sink within concrete. If your building envelope is very good, you might not even need the few hours of propane before the sun raises and the process starts all over again. Remember the coldest winter days in northern climates usually have blue skies and limited cloud coverage, making it ideal to generate solar gain. And thermodynamic solar panels is yet another option...
I worked in engineering for supermarkets many years ago and one design feature we often did under ice cream storage freezers (in the back room area) was to ventilate the slab like this to keep the freezer from freezing the ground under the freezer. A small 120V fan would simply circulate ambient air from the warehouse space through the piping. I've worked in other engineering areas with cold freezers and wondered why we don't always use that system.
This is a neat system. The energy efficiency sounds like it would pay for the installation pretty quickly.
Frost protected shallow foundation, with in floor forced air heat, pretty cool. Matt, I would love for you to do a video of a FPSF. Why go with electric resistance heat instead of heat pump? Then heat pump (in reverse) could cool slab in summer.
We went with the unheated version of this as recommended by Legalett for our location in western Vermont. Thanks guys for turning us onto this amazing foundation method. It's perfect for our situation.
We are currently in the excavation stage for a new house in Nova Scotia. We’ve been passing drawings back and forth with Legalett for months, it seems, and we finally have their plans in hand. It’s hard to get contractors this year but we’re pushing to have the concrete floors installed as soon as possible. For our house it’s a 3-step process: the lower floor gets poured and set up, then we install and pour ICF walls around it, and finally we pour an upper floor behind that. From the side the house is L-shaped, with only the front of the house having a basement, and the back of the house being slab-on-grade. That’s because the lot is pretty steep, rising 14’ up to the main floor level. We’re not using the Legalett radiant heating system because it’s a passive house and we need very little heat overall. Since we’re going to use a fully ducted heat pump for cooling, we might as well get what little heat we need out of it too.
Huh.
In 1985 close to Liverpool Texas I built a 2 bedroom house on Chocolate Bayou that had 3" galvanized metal ducts run in the floor exactly the same way because I'd read as a kid about the Roman floor heating system and wanted to try it. I used a salvaged mobile home downdraft / underfloor duct heating system. Yes, it's close to the Gulf of Mexico but there are a couple of months of cold winter temps that require house heating. Unfortunately, I'd never heard back then of putting insulation under the slab so it didn't have that.
I also used 2x6s to build the external walls so I could add 2" of styrofoam and then regular 3 1/2" fiberglass. Back then double pane windows were rare and definitely special order but I used them.
When everyone else was spending $400 a month on AC cooling their local homes (remember, it's the 80's), my electric bill was $140 in August, the hottest month.
And in winter months (after I got the thermostat regulated) the house was toasty and had very low bills.
amazing!!
Thanks Matt! More of these systems and interviews! 🙏
Student from ACC who emailed you long ago about how awesome you are. And today, it’s still so amazing to see how much of a pioneer of construction and the talks of best practices of technology you are engaging in. You’ve always been an inspiration Matt, a family man, and a teacher. I love your work and what you do, you’re a true American man. Take care, and never lose sight!!!! - John
The Legallet system has been around for a while and the training provided in Halliburton, Ontario is really pretty good. They also offer a passive wall system for outsulation that’s, when combined with other products and sealing tech provide super air tight and efficient buildings.
Hmmmm..... my biggest concern would be whether the slab would be structurally adequate for its intended purpose as from the photos it appears there is not much concrete cover over the heating pvc pipework to the slab surfaces. The other concern is that the heating unit in in the slab itself, which would be almost be impossible to service or replace in the future. I would have extended the pvc pipework (the entry and exit points) protruding through the slab with a collar and then connect the heating unit on top of the slab for easy maintenance. Another consideration is there is no foam sleeve around the pipework for possible slab movement within the slab or slab flexing. Depending on the soil classification this would be accessed. I would have used a electrical wire grid system installed close to the slab top, (like tile heating in a bathroom) across the whole slab which could be installed after the slab is laid, (aaprox 50mm topcoat on slab itself) . This would give a better heat transferred as it is closer to the surface, could be replaced or fixed a lot easier if faults occur, could be zoned in more areas for energy saving, solar powered, and be a cheaper system of heating overall and maintenance. I hope that concrete was adequately vibrated for higher MPA concrete strength!
I wonder if the company thats been making this for decades ever considered these things?
@@mattbrew11 this is probably news to them. Most RUclips commenters are experts in anything.
I would really like to see a hydronic heat pump system discussed -- air to water or geothermal.
Specifically, I would like to see a discussion with Enertech about the newer Advantage System.
Its all good till it leaks
Three things... The static pressure of 4" pipe requires a lot of power to overcome. It's likely that if you used a thermal camera you would see the pipes fade to blue from the supply. Secondly, you would have to be proactive in ensuring that it won't end up being a giant Habitrail for rodents. One season of not getting that cover sealed will have all the tubes clogged with nests. Thirdly, PVC is not a good conductor of heat.
The pipes are a closed loop system without any outside air entering so no chance of rodents or bugs. The distribution box comes with a lid and prior to the permanent heater being installed the pipes are vacuumed out. The pipes are also fully insulated as they leave the distribution box for the first 10-12% and then 1/2 insulated for the next 10-12% so the hottest air is moved farther down the line to get a more balanced heat distribution. The zebra striping of hot and cold across the floor typical of hydronic does not occur with a Legalett system.
This was very timely! I am starting a project that, hopefully, will showcase new and innovative products for passive and eco-friendly building. I am up in Canada, so it's nice to see some of that innovation coming from here!
This system was invented in Korea probably 2,000 years or more years ago. The kitchen is at one end of the house and a little lower than the other rooms. Traditionally, they cooked with charcoal. a chimney went up from the stove but a shut would have the heat go through a tunnel to the other end where there was another chimney. They slept on the and the heat rose so that the entire room was well heated.
Ondal (pheoetnic spelling) is indeed a Korean innovation and I have slept on heated slab many times (on a mat). The key downside of the system was the charcoal burner was vented by clay tile buried in the slab. The tile would fracture over time and the carbon monoxide would leach into the concrete and eventually into the room - CO poisoning is quite common so leaving a window slightly open is a common practice. Very strange that your body is warm but your breath condenses at about 12 inches off the floor.
@@AFITgrad86 I've spent many a night in homes heated with that system. My late wife was Korean. In the 50s, 60s and 70s I managed 51 trips too Korea for lengths from a few days to a year. Korean also had the first iron-clad vessel about 270 years before the Monitor and the Merrimac. And there was the Tripatica. a few centuries prior to Gutenberg, and the first suspension bridge in the 1590s. Admiral Yi, the man who created that iron-clad ship devised naval tactics that were used by the Japanese in WWII and are still taught today in some countries.
The Ondol was sort of co-developed in both Korea and northern Japan... it's hard to say where the first iteration developed in that region. That said, the concept has appeared numerous times in history in very different locations, presumably independent of each other. The next most famous example is the Roman Hypocaust, which was contemporary to the Ondol in time. There is even some possible evidence that a similar system may have been developed as for back as the neolithic in Turkey roughly 10,000 years ago, although the evidence is contentious at best.
@@AFITgrad86 The Romans invented concrete. It took a very long time for it to get to Korea. You are obviously unfamiliar with the construction of the Ondol system. In Korean it is called gudeul. A clay floor is laid down and a cavity is gouged out. Atop that is a combination of stones (godeuljang) and more clay. The stones retain the heat longer. This is topped with oiled mulberry paper, making the floor waterproof. It seems likely that this was responsible for the custom of removing ones shoes before stepping on this flooring. Crediting the Japanese with it is a stretch. The traditional name for Korea in Japan is "The Land of Gentlemen and Scholars." All, or almost all, court scholars in Japan were Koreans, bringing their and Chinese scholarship. You've heard of kombucha? The West first ran into it in Japan. Kombu was apparently the name of a Korean court scholar who introduced it from China. Cha is tea. It is one of the very few words common to Chinese, Korean and Japanese. The Koreans have always been creative. They created the first ironclad ship and the first suspension bridge during the Hideyoshi invasions of the 1590s. They also beat Gutenberg for a moveable type printing press by more than 2 centuries. The Tripitaka still exists. They created an alphabet in the early 15th Century that put their literacy rate far above their neighbors for centuries.
When I was in South Korea, a lot of homes had pipes like that in the foundation and they would use coal powered heaters to heat their homes. It was dangerous because if the foundation cracked, carbon monoxide would seep up from the cracks and kill people. Glad to hear this system uses safe electric heat. :)
the problem in Korea was that they laid tin cans end to end and then poured concrete over them. If they had used stove pipe there would have been fewer deaths
Great heating/cooling system. Imagine what could be achieved if combined with a Canadian Well heating/cooling system. Bet you wouldn't even need any energy consuming mechanical equipment of any kind. Full passive.
The void solar panel is a must try. If it's tight enough you could move the air with some 12v DC fans conveniently located and powered directly by 1 or 2 photovoltaic panels. It's amazing what can be achieved today. Congrats and Mat, thank you once again for the heads up.
This is so kool! I saw something like this in Fine Home Building, the foundation that is. Im planing to build a barn, heat it with wood, I have a endless free supply. this heating set up looks far more simple and reliable than any fluid. I suppose the only thing is how hot the air is going into the piping. I love my truewerk gear. It moves like nothing else and is super durable.
Very interesting. Thanks for sharing. We live in a much colder climate with -30C average lows in January and a few days of -40C/F. It’s in the mountains of Mongolia. We use electric underfloor heating supplemented by wood/cow dung furnaces in our gers (“yurts”). Electricity is cheap or even free at night. Fallen wood and cow dung is free on our land and the common land around.
The insulation in the walls/roof is wool felt and basalt/volcanic rock in the foundation.
How was the Yurt isolated to contain heat inside with -30C outside temperature?
I mean.. if it’s just wool - how thick was it in order to ensure it withstands -30C outside.
Thx
@@offgridatef1102 Actually, Mongolian gers (aka yurts) aren't really insulated very well. The wool felt is about 10cm thick (4") in the walls and roof. The base is insulated with about 20cm (8") of basalt rock mixed with loose gravel under a concrete slab. I believe it's maybe equivalent to 4" of EPS.
The solution is to heat the heck out of the gers. Since electricity is dirt cheap or even free at night in Mongolia, it's possible to keep it comfortable by just using a lot of it. During extremely cold weather we can supplement the electric underfloor heating with wood and cow dung - free on our land and nearby common land - in a stove.
We thought about adding an extra layer of XPS (5cm / 2") in the floor but it probably wouldn't pay off in the long run since the walls and roof are greater sources of heat loss. Also when energy is cheap (or free) it's hard to justify an extra $1000 for the XPS.
@@martinfoster5163 Thank you very much!
I will try to experiment with my future Yurt next year, but without electricity.
30cm wool insulation (it’s almost free in my case) and mechanical heating.
@@offgridatef1102 Wow, 30cm is a lot. I suppose we could get more wool felt too because it's quite affordable here with 45 million sheep. However, how to attach it would be a challenge and, like I said, it wouldn't necessarily pay off.
You two make very good content together. Nice video!
thank you for this, yes please follow up on the design of the rest of the house. also i have been wearing Truwerk since the beginning. Love the pants and shorts they are game changers.
That is such a neat 💡 idea. It's definitely an improvement over the idea from the '80's that DIY solar cells that circulated heated water inside a framed 4×8 black plastic, that blowed the heated air thru the HVAC system.
What takes care of the condensation in the piping?
And the mold?
This is what they do for the slab for cold storage facilities.
Seems so much smarter than with water
Add air heating?
@@mabamabam not really heating but more conditioning.
Great idea! This could even be tied into a home-made air heater if one had enough cans to make it. If this was tied into a passive air transfer system using grill panels in the floor/ceiling as was done in Craftsman homes and earlier, it could almost be fully passive heating. Nice!
this is awesome. every since learning about the ancient Roman and Korean fire- heated floors, I've been thinking of modern ways to implement that concept. this is brilliant. I wish they'd talked about the details of wall-floor interface, etc. but really, really cool. thanks!
Fire heated floors work better and are more efficient.
Hi,
my father built our home in Kiruna, Sweden, far north of the polar cirkel, 500 m above sea surface, in 1965-1966, with a similar system for heating.
And?
@@christophernunn943 It worked!
Friends of ours just built their home using this system. Incidentally, the air panel you are speaking of is from either "Your Solar Home (SolarSheet) or Conserval's SolarWall. Both Canadian companies who invented solar air heating. NREL is on record as stating that SolarWall exhibits the highest efficiency of any active solar technology in existence and has their newest building clad in the system. It is typically used for commercial/Industrial construction whereas the SolarSheet is a residential product that is typically set-up for 100% recirculation.
Good to see old design approaches updated.
The design principle for the foundation has been around awhile - US Corp Eng. And Adopted in Europe.
Same for the air type under floor heating system.
I worked as a University solar research assistant on homes that used similar piping in "rock storage" . We tried Winter heating connected to Trombe Wall. ,and summer cooling to ground source air pipes.
Nice to see these alternatives in practice.
THANK YOU, BOTH! You just "made my day, Pilgrim". Looking into Hypocausts... so sensible and more affordable.
We built our house like this in Canada in 1990. A floating Alaskan slab with HVAC pipes throughout. Works great for our passive solar design with geothermal forced air.
Thanks for inspiration - nothing like hearing a long term report.
This is my primary choice for a foundation of my retirement home I am planning in the next 10 years. This system can be combined with icf walls and additional exterior foam. It seems like a reasonably straight forward way to meet passive standard.
Not having a basement will hurt my resale value, but oh well...
The ultimate dream would be to encapsulate a house in a greenhouse and create your own microclimate.
I saw gentleman in Nebraska that built a greenhouse, and home. He was growing citrus trees in the winter. I’m sure you can plug into a RUclips search, and find it.
@@garyb.4080 Thanks, I will look for that. I am in Ontario, and the citrus trees would be quite a challenge in this climate, but a reasonable growing season without huge energy input should be attainable especially if I use passive solar principles. Summer overheating is more of a concern.
Interesting video. I am looking forward to see if you do another on the rest of the build especially the outside covering. It looks like the roof and walls are made in one piece sections. The roof comes down and just curves over and down the wall. I have never seen this used on an A-frame style house and looks very efficient and water tight. I have seen curved metal roofs on carports but never seen it used on a house at least not in my area.
The house ittself is super cool. Would love a video covering all the details!
Would love to see Steve B. go over the build plans of this house! I'd settle for a link to the plans though. I'm considering a build in MA, not quite as cold as CO rockies and am interested in affordable high performance homes like this. $20k for foundation plus heating system sounds like a big win!
For what it's worth, I think $20k is just for the radiant system, engineering and associated materials (foam, vapor barrier etc). I imagine the forming, rebar, concrete, labor, finishing etc cost him an additional $10k or more. Still a huge win tho!
Someone in Maine (and likely other states) was making something similar but using the holes in cinder block as air pipes and covering the blocks with various flooring types (including concrete). They used the roof as a solar thermal collection to make the hot air to go through the cider blocks. This system should be far more durable as cider blocks can break easier than actual concrete.
Subjective as you could lay 4” thick block on its side on a thin footing slab and then grout the seams pour over the top with another layer of concrete.
Fantastic video on the Legalett system. Gotta love Bryan's cre8ivity and willingness to go for it with an unconventional approach.
Great stuff! Thank you and I really appreciate you sharing!
I am interested in geothermal with pipe beneath the home. I wonder if a combination of these two would work - and be worth it - in milder climates where a heat pump would replace your electric heater. I"m blown away that your "foam" can hold up the entire house without being pressed flat
XPS foam panels are used around foundations because it resists compression.
I have a layer underneath my pool to protect from rocky soil
Using air instead of water is probably a smart move for a house that may not be occupied all the time. However, air has a _much_ lower heat capacity. You have to move a _much_ larger volume of air to compensate. Personally, if I was staying there regularly during the cold months, I’d opt for hydronic heat. Maybe I’m biased but I’d have to see it in action before I’d be convinced that the performance is as good as hydronic.
I guess it doesn’t really matter if your heat load is super low
Air holds more heat the warmer it gets because it will hold more moisture. If you can hold 85F air at 50F dew point you’d be in a great spot. Subzero refrigeration companies that do bulk cold storage use this same type of cooling to regulate the building slab.
100mm pipe is 16x larger than 12mm pipe. And it only takes tiny pressure differences to have massive air flow.
Have built two homes with this system. It performs as well or better than Hydronic. It is a closed loop system with no heat loses using the electric inserts as there is no external heat source.
@@boylston418 nice, have you compared it against the cost of running a hydronic system? I thought water was a better medium to transfer energy through than air. Much more efficient
. Seems like this system is cheaper up front but hydronic would be cheaper over time?
Muy bueno, les felicito !!!!, Saludos desde San Luis Argentina!!!
I love this idea and would like to start one on my Craig Colorado lot!
This would be great for gas, wood or solar heat but for straight electric resistance heat it would have been so much easier and cheaper to use electric grid heat in the concrete. The insulation is what is notable here. 👍
the electric grid does go bad in 40-60 years so the air pipes makes sense even if the plastic pipes crack it should be still a working heating solution as long as the foundation is solid.
Back in the late 50s, a guy, Eugene Sternberg, built some fun smaller MCM houses in Denver. He heated them like this. It was as an alternative to hydronic floors, which at the time used copper.
neat
I owned a really neat custom built bungalow that was constructed in 1952. Really neat custom features were all over this house but one of the coolest features it had was in the basement. There was a poured pad then a joist system 6” high throughout the whole basement. The joists crisscrossed the flooring but ended up 12” from the wall in a serpentine manner. They were braced by the concrete pad so no buckling etc then at the turn. My buddy and I finally figured it out that they actually had a heat vent off the furnace that fed into this labyrinth and then found a small vent by a window so in effect it was the same as the system in the video. That basement was very comfortable.
This is a very interesting method application of an ancient Korean floor heating system. Koreans have been air heating their floors for more than a thousand years. Keep promoting this method, and hope it does catch on, regards.
I live in Cleveland, Ohio. A Canadian border city, it gets cold here.
My cheap slab house has a downflow furnace, that blows hot air through six inch clay pipes under the concrete floor.
It stays barefoot warm in the winter, and all that expensive stuff you are getting paid to sell is not needed.
I expect the foam insulation is the greater cost. They said the pipes were thin wall.
I’m a builder in Saskatchewan Canada and we do in floor heat all the time we see temperatures up to -50with the wind this is a very interesting system and I’ll be looking into more information on this thanks for the update
I build in BC, we do legalett systems all the time but never air piping
If you are interested in heated floor, check "ondol" system most Korean builders use to heat up the floor.
I'm going to be building out the shell of a house I bought in the mountains of Montenegro in a couple of years. I need to ask my architect if she's ever heard of this. Heated floors are pretty common in the Balkans in the mountains, but usually hydronic or electric. Awesome intro to a product I've never heard of.
Back in the 80's-a forward thinking customer asked us to build an, admittedly more primitive, early version of this type of system using CMUs to create ducts-it was easy to build, cheap and very effective. Built on a slab, with a membrane and sand and another 3" slab over it-very effective and still in use. Talk about THERMAL MASS. PS> This is Maine
This principle has been in use in Korea for several thousand years. Check out the term "ondol" for more info.
I have seen a few builds like this with "passive" cooling/heating setups that go through the floor, walls and roof.... pretty much making heating and cooling *FREE* all year around
very cool setup, Matt. Reminds me of the climate batteries/annualized geosolar basement setups also use snaked air tubes like that, only instead of heaters in slab, they use a manifold type pipe running along the top ridge of the ceiling to pump hot air back down into the slab. IDK if that type of setup could be added to that maker of that system, but if you check out the Greenhouse in Invermere, BC, Canada they have a big annualized geo solar setup that keeps it above freezing all year just with a fan for the top pipe. Would love to see you do a series of videos melding your ideas with "off grid" or "green building" like Cob, Passive Solar, Earthship, Earthbag, etc. type homes XD
Build a house in Flagstaff AZ the same way. Though the contractor bailed on the PVC, and just used long runs of corrugated drain pipe. Had a basement under part of the house and ended up with a pellet furnace pushing the air into three parallel runs. Leaked wherever the concrete was cracked, but that was ok. Never got super warm (the slab was not initially insulated), but it kept it comfortable enough through the winter.
LOL. The contractor was an idiot. corrugated drain pipe will react with the concrete and rust away over time. PVC is inert and will not react with the concrete.
In the early eighties my dad built a house , that has this, but he used irrigation aluminum 4in pipe , plus he has passive-solar. Someday I hope to finish the house as he didn't have the money to ever finish it before he passed away.
It's an interesting idea but I've never seen it work.
Aluminum is a bad choice for the piping. Use PVC, it will not react with the concrete. Aluminum also expands at a higher rate than concrete, so the pipes will eventually break the concrete apart.
@@pyhead9916 interesting concrete looks perfect not 1 crack from 80s also aluminum looks ok-need to put a camera in to see for sure. Wonder if he put some coating on the pipe?? Or did other things to stop corrosion, as really concrete looks great no cracks. 40 years old nearly. I was just reading also if you install aluminum in concrete and are carefull, following some key steps this works. Of course probably not by building codes of today . I know we avoid aluminum and concrete. Doing solar pv
many thanks!! all that ideas will be useful to my house in Mendoza, Argentina, close to the Andes
Excellent video very informative... Thanks..
Thom in Scotland.
I wonder about the density of the foam beneath the foundation. Like psi capability for house support, over 50 years.
When designed correctly, yes.
I have had no issues for 20 years. Brilliant and very energy efficient system. I am installing another in my new log cabin. I did not want to live without my heated floors here in Canada.
Plus, in the summer it feels like we have AC, but we don't, it keeps the house cool.
I wonder if you could make this geothermal. I've seen a greenhouse use a similar set up, running the air through a woodchip pile, i womder if the solar idea is to run air through a black panel on the roof. Like water solar heating
That is what i was thinking. Using a closed solar water system and run air over it.
I’m looking at retro fitting a heating system using the plumbing alone.
I’m in a coastal climate with damp cold and high winds,so heat loss is a given.
I’m thinking along the lines of combining a refractory masonry box, heating the box can create temperatures from moderate to red hot. Routing piping to my water heater can fit to existing radiators.
Abundant heat that can be modified to meet any conditions and diverse fuels.
Propane, wood fuels,solar input.
Thanks for bringing this to our attention.
Well done.
Excellent stuff bro. Truly Amazing
You've reinvented the Hypocaust system used in ancient Roman buildings. That looks like a great option to a standard hydronic heating/cooling system, especially in a vacation home in colder climates.. I'd like to see an option to use a heat-pump, preferably geothermal, rather than the in-floor units shown.
there isn't any reason why this system has to be electric resistive heating, the in-floor units are probably just a duct fan and a heating coil... just bring the pipes up out of the slab and plumb them into a traditional manifold.
@@kschleic9053 because a heat pump is reliable below 32F.
Diminished returns installing geothermal and if in Colorado almost impossible getting by ground water regulations. Well drilling is expensive in dirt, digging rock is even more expensive.
@@RaddestDad Understood, but a geo unit CAN be closed loop. And if you get below (about) 10' from natural grade you have a pretty constant temperature which is what a geo heat pump loves.
@@RaddestDad Modern heat pumps are reliable to 0°F. Either way you'd save 4x the energy in mild months. Worth every penny.
Are there no "settling" issues or concerns with this type of foundation? And where do they mount the walls at? I see foam around the edges of the concrete... do they mount them to the concrete before the foam?
hello jem jones. i suppose that it is rather a soil than a foudation: the enveloppe sits on a real foundation( mortar and. .. i do not remember the name in english) and the interior walls, sitting on the pex and mortar are just separating walls with no weight on it.
these videos are so entertaining... i jus found them, KEEP THEM UP!!
I am liking this--- wow in the mountains - I am curious if you have a drain in it in case a pipe in the house breaks and floods it. With that tight of house- you would have a air exchanger- have that in the eves on a south facing side of the house to try and pull in warmer air?
You know, I grew up in Colorado during the 70s, and that is where I saw most of it. The Western mountain states are probably the best areas for passive solar heating. I also worked a summer in New Hampshire, though, and I saw it there as well. They don't get as much sun during the winter, but what made it work there is that the building codes were lax, which allowed a lot of homeowners to innovate with their own designs. The people I met were very happy with their passive solar homes. I wonder what they think after 10 or 20 years.
My question is how does the thin-wall piping and foam handle the weight of the concrete long term?
Well, there are 2200 year old examples still intact so...
@@mcamodell Thanks for a useless answer
Thanks for the stupid question.
@@prestonthomas9406 Once concrete dries and sets there is no load for the PVC pipe to carry, concrete under and around the pipe will carry the weigth of the concrete above it. You could even remove the pipe, there would be no difference.
Interesting information, thanks guys
A very interesting concept, thank you for sharing. Curious as to the purpose of the 4" holes in the sides below metal wall plate shown at 5:52?
Look up the Geoff Lawton Canadian greenhouse. They take summer air and shove it under the slab with a fan. The heat from summer is trapped all winter and keeps the floor at 70 degrees F all year round.
Huh?
@@jjhays36 referring to using the soil as a battery to store thermal energy
Interesting concept but don’t see the benefit over hydronic. If you are concerned with freezing can’t you just add anti-freeze to the system? Also the rest of the plumbing can still freeze so you haven’t solved all of your freeze concerns. Going to an 8” slab is expensive basically doubling the slab thickness and won’t be able to have good solar. For solar to be effective you need heat storage and air cannot hold heat like a water tank can. Grab the heat during the day then pay out at night after sun has gone down and you need the heat. Hydronic can cool the slab in the summer if you use an open direct system, using incoming water to cool the slab for free.
No, or almost no pressure, and therefore little chance of leaks.
Same thoughts here. It's pretty cool but the specific heat capacity of air is much lower than water. I guess both heat the foundation, and that has more volume than the water or air pipes, but the "stored energy" in air is relatively 0 to water.
@@62Cristoforo most pex is rated to last 100 years, I would not put any fittings in the slab. So long as you are reasonably careful during the construction the chances of developing a leak are extremely remote. Also depending on the type of system installed hydronic can operate at only a few psi. Personally I like open direct systems because of the free cooling you get during the summer and the simplicity of the heating equipment and even at ~50psi it is far less than the burst pressure of pex.
Not to mention the leggalet system is so overpriced for what they supply. I got full hydronic kit with engineering for a fraction of the cost. Then factor in the cost to produce the heat from electricity. Ouch.
Hi I am wondering who you used for your radiant design? I am looking at radiantec in Vermont and just wanted to see who else is out there. Thanks
I would be interested in that exact design!
I head off to South Florida from chilly New Hampshire around mid October. I hate leaving my furnace running all winter. I leave it at 50*F in the cellar, 55*F on the 1st level and 50*F on the upper floor. I use natural gas for fuel in a newer furnace. I shut the hot water tank off completely. I don't know (because I'm stupid) how to winterize my home w/o worrying too much about everything. Unlike the old days when I ran an old Ecoliner Oil Burner Furnace to the point that the fire box did not exist. I sometimes had the furnace man tell me the patch he used to seal the boiler could last 6 hours or six months. Not a good feeling when I'm turning the deadbolt on the front door while my ride to the airport is waiting. God watched over me! All was well when I returned! My home was built in 1930 and now has insulation. The place is drafty, but when everyone else at work was sick I would tell them that I have a "built-in" air exchanger and I would stay sick free!
How did this get through inspection or permitting. Was it difficult?
Probably it's in the middle of no where so no permits or inspection needed.
This is BS
Have had no issues with inspections. In some canadian provinces it is eligible for reduced power rates as well.
@@trimble1049 what do you mean?
This kind of foundation is allowed in the IRC code book it's called a frost protected shallow foundation. I believe it has to be engineered though because it has the foam under the whole thing.
Dunno if they'll get into this later in video, but my heart sank seeing that electrical heating unit. It seems to me that this is the perfect situation for an array of evacuated tube solar collectors as the heat source. I would use them with the resistance heating as only backup. In fact, why not put a ground loop and use a heat pump? Anything except resistance heat!! So wasteful.
do air - air heat pump work in cold environnments?
I am intrigued. I would probably stick with a traditional foundation but install this in the floor. My first thought is that this could be very DIY friendly. All parts can be purchased from a Home Depot style store. Design layout would probably take some thought.
Why couldn't you duct it directly into a forced air furnace? Instead of purchasing the "hair dryer" heating unit? Have a diverter to feed the floor and not the house when you are away. Then use the forced air to warm the house quickly when you get there.
Looks like a great system. Thanks for the video.
Additional tip use Glas grabble below instead of stone... easier and better for water runoff
Dalle Isoslab is another Canadian company that does insulated slabs like this.
Yes and is more easy installation and cheaper option on concrete and rebar.legalett is raft slab,iso-slab is monolitic slab with military airport technic design,with customer choice about electric or water radiant heathing system.
@@benoitdelorme5256 I build legalett on the coast all the time, never heard of this one. I will check it out thanks
Half fill the pipe with water to hold it down till concrete sets, then pump it and air dry it while construction is going, really it should have a drain and slope anyway..
Neat system guys but I don't think it world work in south Georgia. Any ideas for cooling? I use a package heat pump at the moment
in a different climate, a drain would be a must... in high alpine Colorado, the air is so dry all year round that it isn't really a consideration. A cup of water will evaporate empty in a few hours if there is a breeze blowing across it😂
Best building convo's on RUclips. BOSS!
Cool info, thanks for review
I did this but accidentally plumbed my toilet into it
Hot shit
Air Doesn’t Expand or Freeze 🥶
Genius really.
* we had an Air based, Solar Panel system, 1980’s. Again just Air Blowers and Censors.
One of my friends has a similar system on his south facing roof. Surprising how warm the discharge the air is.
Air doesn't expand? Physics doesn't apply to air? How does our weather work then?
Thanks Matt. I am a big fan of your work from Australia. I am moving soon to Ottawa and found this video very interesting because I am actually looking to build similar A frame lodge around Ottawa/Montreal. Could you please make a video with Brian about his A frame project it looks awesome and would love to learn from you and Brian. Thanks a lot. Top bloke Brian 👏 👌
Contractors and engineers in Australia approach housing problems in different ways than America.
Look at solar troughs, and consider that you can use transparent plastic tubes outside black-painted metal pipes, concentrating solar with cheap metal mirrors onto the metal pipe, and you circulate air both through the metal pipe and between the metal pipe and transparent tube, and get that heat into your underfloor air heating pipes. If money are not a problem, you can use metal flat metal mirrors with fresnel lenses to concentrate sunlight onto metal pipes places close to the wall of your house, and have the pipes lowered or raised automatically once an hour to maximize the solar concentration. And you can also use a stirling engine or low-temperature steam engine (which uses another substance instead of water, whose boiling point is lower than that of water), to use the excess heat for making electricity.
Putting a sheet of poly over the tube before pouring will probably keep the pipe on the ground…. Nice stuff