Any opinions on this system? Do you agree that it’s the first “green” foundation for a basement? http://www.steelpanelfoundations.com/
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DenverKevin,
I'm not sure green would apply here.. much steel is imported from countries without good clean air standards. Even stuff extracted from american sources there is an awful lot of energy consumption in it's creation, manufacture, and distribution..
Yes, but even if steel produces ten times the CO2 per pound as concrete, steel would be greener because a concrete foundation weighs over 100 times more. Steel is recycled into steel, concrete is recycled into gravel which would be more costly to remove from the site in the future.
Denver Kevin,
Again we need to look at the source of the raw materials and the energy used in it's production.. most concrete is made from mostly local materials and thus requires relatively little energy to make..
Second is durability of foundations.. Someone pointed out stone foundations have been around an extremely long time and have endured even longer.. new technology is at best a guesstimate of potential durability under certain circumstances. Not proven as is the case of other systems.
When you start mentioning recycling foundations I shudder!
So many homes were built using old growth Douglas fir and then within about 50 years are either torn down or so dramatically remodeled that most of the 2000+ year old fir winds up in the dumpster.
The European model is superior, build a home to last centuries rather than decades. That way the replacement tree has time to reach the maturity required to provide a new home when the first home no longer will function that way..
starting out with a foundation who's main advantage is it's ease of recycling isn't the way to achieve that centuries of use.
OK, for the sake of keeping apples to apples, I'll agree that foundation recycling isn't an issue even worth considering.To me, sustainability is conserving resources and money. So, if a lightweight steel foundation costs less, uses less raw material, AND lasts just as long, then it's more sustainable.
DenverKevin
As I said that has durability to be clearly established.
I am not against new technology, heck I embraced SIP's and ICF's long before they became acceptable. A steel foundation hasn't won me anymore than treated wood foundations did.. It may have it's application and I can see where the potential exists from dramatic labor savings, yet I remain unsold.
"most concrete is made from mostly local materials and thus requires relatively little energy to make.. "
Concrete has very high embodied energy because of the kiln production of lime from limestone, as well as the energy required for mining, milling, mixing and transporting.
Precast concrete has 2 mega joules/kg of embodied energy. Concrete production is also a major contributor to global warming.
Steel has 32 mj/kg of embodied energy, and even recycled steel has 8.9 mj/kg.
In a typical house, the concrete foundation contains the largest amount of embodied energy because we use it by the ton. A steel foundation would probably be comparable.
Merely in terms of embodied energy, a local stone foundation would certainly be the "greenest" at 0.8 mg/kg, and an All-Weather Wood foundation would likely be in second place.
ICFs have both the embodied energy of the petrochemical foam (117 mg/kg) and of the concrete used to fill the cores.
The "greenest" foundation is one that avoids the excavation and material use of a full basement. Given the energy-efficiency potential of new homes which can use a central heating plant that fits in a closet, the only reason for a full basement is too much stuff - and it's the American lifestyle of over-consumption which is anything but "green".
I build on shallow, frost-protected foundations or rubble-trench foundations which require minimal site disturbance, minimal excavation and backfill, and minimal material usage. Here in north central Vermont, with an 8500 DD climate, my footings need to be only 12" below grade if they're insulated properly with vertical and wing insulation. I can form these grade beams myself with the same rough-sawn lumber that I'll re-use as floor joists and headers (by protecting them with poly).
With simple, effective, and efficient cost-savings and material-savings methods like this, I can build a passive solar superinsulated house with 12" walls (R-40+) and R-60+ ceilings (with 100% recycled cellulose insulation) using less lumber than a conventional 2x6 house, and it will consume a quarter of the heating energy. And I can build it for $110/sf.
THAT'S GREEN!
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Edited 1/27/2008 3:36 am ET by Riversong
Edited 1/27/2008 3:38 am ET by Riversong
ya beat me to it. The most green basement is no basement I think part of the idea of these steel foundations is that the are better living environments. So if you actually down sized the upper floors (not very American I know) because of the gained space below wouldn't that offset
the energy lost quite a bit?
I think part of the idea of these steel foundations is that the are better living environments. So if you actually down sized the upper floors (not very American I know) because of the gained space below wouldn't that offset the energy lost quite a bit?
I don't know what would make them "better living environments" other than the sales literature of the manufacturers. Concrete is sort of the modern version of the earthen materials used for millennia for housing, but much less forgiving and much more brittle. Steel is a very "cold" industrial material that has not made inroads into residential building until recently, except as basement girders and posts.
You could certainly argue that reducing above-ground space (perhaps one storey instead of two) would be a "green" tade-off, but only if you were building the upper floors with high-energy and high-environmental-impact materials such as imported KD and manufactured lumber and sheetstock, petrochemical foam insulation, and Hardiboard siding. If, however, you build with "greener" materials and methods, then the wood-framed assemblies have much less environmental cost than the basement structure, and they allow for a healthier and more liveable indoor environment because of views, natural daylighting, passive ventilation, and solar gain.Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
For instance, here's some pictures of a local "green" house that used Superior precast panels, heavy and light steel framing, spray foam insulation, and steel roof with copper flashing.
The only thing "green" about it was the reuse of the rock that was blasted from the site for the veneer. The Energy Star inspector said it was a nightmare of thermal bridges.
And I would say it's not "green" also because it does not fit the local vernacular of design in the center of this New England village, right across from a historic covered bridge.Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
I was referring to the manufacturers claims (no Idea of the validity) As to the upper floors, my thought was only regarding a substitution for extra materials needed up stairs (again Not sure just hypothesising). So in that light while green/hyper efficient would obviously be better that's not the point. Less building is always more green,cheaper and more efficient.
By the way a root cellar has been useful for millenium.
I am all for on grade slab foundations,they have proven them selves for many years in Alaska. No argument about that.Yet living on a concrete slab is not for everyone.If people don't like the end result then the method is not a success. And like it or not people tend to have a lot of stuff, our job is to accommodate the customers want and needs.Any time we can do that in an environmentally sound manner I believe it is our responsibility to do so.But to say "you don't need all that stuff" only alienates potential partners in a difficult situation.Look for the best solution to what the customer demands and you will have ACTUALLY helped.
River I think you and Frenchy are both right --But-- I think he was talking about concrete while you are talking about cement the stuff concrete is made out of.But you are right, that stuff is very nasty and dangerous to manufacture,I know first hand what kind of stuff goes on in the manufacturing mills that produce the grey gold,I spent 24 years the first time in one and lasted 2 more years the second time I went back,uck! hated it worse the second time than I did the first time.
I think you and Frenchy are both right --But-- I think he was talking about concrete while you are talking about cement...
The embodied energy numbers I posted were for concrete, not cement.Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
do you not have to go below frost level in vermont?
do you not have to go below frost level in vermont?
A foundation needs to be frost-protected. This could mean excavating below the frost line, or building a shallow frost-protected foundation (as per NAHB guidelines), or building on a well-drained crushed stone bed sitting atop ledge as in the "green" home above.
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shallow, frost-protected foundation
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Edited 1/28/2008 8:09 pm ET by Riversong
What would you use to insulate your shallow, frost protected foundation in an area where the carpenter ants will even chew up and nest in pink fiberglass insulation? I have not been able to find any boric acid treated insulation in the area, although I have heard that there is a company out of, I believe, Georgia that makes rigid foam insulation with impregnated with boric acid.
What would you use to insulate your shallow, frost protected foundation in an area where the carpenter ants will even chew up and nest in pink fiberglass insulation?
That's one of many reasons I don't use fiberglass insulation of any color. But I always cap my foundations - and foam board - with a "termite" barrier. Those pesky little critters might tunnel up inside the foam, but when they realize it's a dead end, they'll go to the neighbor's house.
You can reduce the likelihood of ant infestation by not burying any wood material around or near the house. And carpenter ants infest wet wood, so they're actually a good indicator that you've got a moisture problem. Thank the little buggers and fix the leak.
View Image
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Edited 1/29/2008 1:19 am ET by Riversong
""...sitting atop ledge as in the "green" home above."" Can you define "ledge" for me . The word is being used here in a conotation I am unfamiliar with.
They can't get your Goat if you don't tell them where it is hidden.
Ledge: bedrockRiversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Thanks , that is what I was thinking but wanted confirmation.
They can't get your Goat if you don't tell them where it is hidden.
"the only reason for a full basement is too much stuff"
No.
Our vehicles average to 175,000 miles and LOVE being kept inside the basement.Liberty = Freedom from unjust or undue governmental control.
American Heritage Dictionary
Our vehicles average to 175,000 miles and LOVE being kept inside the basement.
Exactly what I said: too much stuff.
Anyway, how do you get your vehicles down the basement stairs?
Drive in through the 16' door conveniently located right next to the driveway.
Modern transportation is "too much stuff"?Liberty = Freedom from unjust or undue governmental control.
American Heritage Dictionary
Modern transportation is "too much stuff"?
Unfortunately, YUP.
As much as we all have a love affair with our private vehicles, the earth can no longer tolerate it - and it's sending us a pretty clear message that it's not gonna take it anymore.
View ImageRiversong HouseWright
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RIVERSONG,
Sorry to get back to you so late, Been elsewhere looking for work. The problem with your numbers is that you forget to add back in the cost of lost energy heating the space over it's lifetime. Even if the insulation in the ICF's in the foundation only has an R23 And not the R50 which some claim for them, that is a lot better insulation than stone has or raw concrete. Since neither you nor I are capable of predicting the durability of a given house estimates are really worthless but assume for a moment we are speaking about 100 year house.
100 years of no insulation in a foundation would have a very high energy cost compared to 100 years with an R23. As to your claim of building 12 inch walls for $110 cost more information would be needed to properly judge that. I do know my costs to build with SIP's and they were nowhere near that..
My objection to stud walls has nothing to do with using wood versis other materials.. I like, heck I love wood for all it's beauty and characteristics. Shoot, I built a double timberframe! But I live where wood is readily available cheaply locally. If I lived in the southwest I'd build with adobe, If I lived elsewhere I'd build with whatever is a good, durable product.
Wood is seldom that. There is far to much energy used in getting it to where it's needed. I've seen lumber from Alaska shipped to the southeast and southern pine in Canada.. While rail has a low energy per ton it is not in a vacum.. all that steel used to build the rails and trains has a massive energy content..
ICF's while they use energy to make them they are normally shipped around the country in drums or tankers. and only whenthey are in the location they will be used are they converted into foam.. That alone is a significant energy savings..
Finally we get to durabilty. There are still concrete is use that were first used by the Romans. Virtually nothing they made of wood remains, at last not still providing shelter. That's a couple of thousands years or so.give or take a few hundred.. .. wood simply isn't that durable..
The problem with your numbers is that you forget to add back in the cost of lost energy heating the space over it's lifetime...100 years of no insulation in a foundation would have a very high energy cost compared to 100 years with an R23.
Absolutely. I was only adressing the "greenness" of the foundation system, which was the claim of the OP, not the life-cycle costs of the entire structure. And I was only addressing embodied energy numbers, which should take into account transportation energy as well as frabrication energy (though I can't be sure what's been factored into those numbers).
And the OP was talking about a basement, which may or may not be conditioned space.
Certainly, embodied energy, global warming contribution, water and air pollution impacts, renewability, recyclability, toxicity, contribution to energy savings, and durability all have to be considered to determine if a material, method or system is "green", though I think the term "sustainable" is more appropriate and less vague.
But I would take issue with your statement that "wood simply isn't that durable", since wooden houses in Europe have lasted 500 years, and even some in the US have been standing for 300 years. And if wood regenerates itself (in the form of trees) in 30 years, then any lifespan more than that is "free" to the environment. Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Riversong,
I keep thinking locally, I should talk about nationally but because of all the factors involved that would get extremely cumbersome.. Who would ever stand still for that?
Locally the foundation is conditioned space.. In fact I would expect anyplace where a foundation is actually used it would be conditioned space.. Un insulated the natural temps are at 55 degrees, the temp of the earth below the frost point. Minus the loss/gains of exposed foundation surface area..
You need to understand that the fundamentals still apply. Heat continues to rise, cold continues to settle.. Seldom is there any real insulation isolating living space from foundation space which means that foundation space is conditioned space.
Secondly.
In part the reason I built my double timberframe was because of the durability of some European timberframes.. However I don't fool myself by thinking that wood is as durable as concrete can be.. Nor is it as durable as foam can be.. what is the reported expected life of a Styrofoam coffee cup in a land fill? Was it 50,000 years or something like that? Stone homes made during Roman times still are providing housing today, a couple of thousand years later. Concrete was really first used about that time and where it was used it still remains holding up viaducts and doing other such chores..
Building green is extremely complex. I can buy local wood but since it took over 200 years for some of the timbers I used to grow that means for wood to be sustainable I need to be reasonably sure this place will be solid and functional 200+ years from now.. In addition the complex question of insulation versis energy must be answered. For better or worse I choose to insulate to the very best of my ability rather than use greater energy in the future.
Frankly, I will continue to advocate that position.
Hi Frenchy have read your posts for a while now haven't had a chance to say hello.
I think an important point about sustainability of timber frames is there innate beauty. Time has shown that people value there timber frame homes enough to maintain them. So not only is this one of our most durable building methods structurally but they also adapt to changing life styles and fashions. If the next generation doesn't value the house it will not survive.
There are many other "sustainable" to choose from Strawbale,Cobb, cord wood etc. Even super efficient designs S.I.P. Double walled,frost protected foundations the list goes on. But if they don't inspire love and appreciation from future generations they simply fade away, and must be rebuilt.
Henley,
Thanks that's an excellant point and one that I haven't argued.. I agree completely with it.
Ugly homes are torn down. Nice, interesting, and houses which show thought and concern in their design seem to endure well.
Hopefully some in the future will value what I've done and the care I used in making this home energy efficent and durable. Maybe seeing all the wood etc. will be the reason. Please don't let some wannabe-a-designer turn this place into something it's not!
But if they don't inspire love and appreciation from future generations they simply fade away, and must be rebuilt.
Ah, yes !!!!!
The one ingredient almost always missing from discussions about "green" or "sustainable" bulding: CRAFT.
Near me, there's a world-famous architect who is building what he calls the "5000 year house", as it's almost entirely built of cast-in-place concrete - inside and out.
It's a design marvel, but feels so cold and dank that I can't imagine anyone wanting to live in it at all, let alone for 5,000 years. On top of that, since he's had a lot of unskilled or low-skilled people helping him, the craftmanship is extremely poor in places, and the whole thing just looks like trouble.
(I'll post some pictures when I switch to my laptop.)Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
The 5000 year house?
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Edited 1/29/2008 9:00 pm ET by Riversong
That is a breathtakingly ugly house. Doesn't VT have any taste police? The architect should be forced to live in it.
The sad thing is it would be possible to make a house of concrete that isn't hideous. Poor design and execution to the extreme.Thanks for the pics.
Locally the foundation is conditioned space.. In fact I would expect anyplace where a foundation is actually used it would be conditioned space..
Local traditions clearly vary. Here in New England, basements were initially built as root cellars and later as a place to put a coal-fired furnace and a coal bin. As homes added indoor plumbing, the spring pipe typically entered the cellar where they might be a cistern and was pumped up to the house. As insulation became more available, from rockwool to fiberglass, 1st floors were retrofitted to keep the upstairs warm but sometimes at the expense of pipes freezing in the cellar.
It's a relatively recent phenomenon that we've begun to consider a basement as part of the living space, to be kept dry and heated. Yet I've heard old-timers say that to build a full cellar in New England is like building a swimming pool and trying to keep the water OUT. And undergound living space often suffers from a lack of daylighting, ventilation, and egress.
Uninsulated the natural temps are at 55 degrees, the temp of the earth below the frost point.
Is it that warm in Lake Minnetonka? The ground temp is the same as the average annual air temperature, which is 42°-44° here in Vermont. But basements obviously get some heat loss from the house above.
You need to understand that the fundamentals still apply. Heat continues to rise, cold continues to settle..
Actually, this is one of those common misconceptions that I have to disabuse my students of. Heat moves equally in all directions (by conduction and radiation). It is only warm FLUIDS that rise (liquids and gasses) and not because they're warm but because when they warm they expand and become less dense and more buoyant.
the reason I built my double timberframe was because of the durability of some European timberframes.. However I don't fool myself by thinking that wood is as durable as concrete can be.. Nor is it as durable as foam can be..
In some ways, wood can be more durable in that it is a far more forgiving material than concrete in the event of settling or seismic activity. Just as a tree can bend in the wind, it is sometimes more likely to survive strong forces than a material which can only crack. And concrete is susceptible to shrinkage and expansion cracking, sea water, chlorides, sulfates, and even bacteria - and has little tensile strength without adding steel.
As for foam, the material degrades from UV and other weathering, although the plastic molecules remain in perpetuity. Hardly a durable material!
Stone homes made during Roman times still are providing housing today, a couple of thousand years later. Concrete was really first used about that time and where it was used it still remains holding up viaducts and doing other such chores..
Apparently, the Assyrians and Babylonians used clay cement concrete and the Egyptians use gypsum and lime concrete. The Romans later used quicklime and pumice. Some of those mixtures might have been more durable than our modern Portland concrete, as we see highways and dams eroding all around us.
Building green is extremely complex. I can buy local wood but since it took over 200 years for some of the timbers I used to grow that means for wood to be sustainable I need to be reasonably sure this place will be solid and functional 200+ years from now..
200 years doesn't seem like too much to ask from a house, though the average American stays in a home for 7 years before moving on. But, in addition to durability and longevity, there's also the issue of end-of-life-cycle disposal or reuse. Old timbers are commonly de-constructed and reused, whereas old concrete must be broken up and used, at best, for fill. And old foam... will most likely end up in a landfill or incinerator.
In addition the complex question of insulation versis energy must be answered. For better or worse I choose to insulate to the very best of my ability rather than use greater energy in the future.
Yes, life-cycle costs must be weighed against life-cycle benefits, such as operating energy savings. But, as our structures become more energy-efficient, the life-time embodied energies (including both intitial and ongoing maintenance inputs) become far more significant.
So, while I agree that lots of insulation makes great sense (I've been building R-40/R-60 homes for 20 years), the kind of insulation we choose and its other environmental impacts become very significant, particularly the global warming contribution.
[By the way, what is a double timber frame?]Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
I will take issue with this statement. "...whereas old concrete must be broken up and used, at best, for fill."' Not uncommon anymore to have the old concrete reground into usable aggregate for more concrete. Local insurance company just had their old building demo'ed and every bit of the concrete was re used on site as aggregate. All the steel was recycled as well. If you haven't been aware of such uses it is happening in other places around the country. Asphalt is reground and remade as well.
They can't get your Goat if you don't tell them where it is hidden.
I grew up in an older suburb of Cleve. Ohio. House was built in 1912. Our basement and those of every neighbor I can think of were utilized year round . Laundry facilities, dark room, kids play area for winter , family rooms etc. along with water heater and furnaces were all located in that space. Regional differences I think.
They can't get your Goat if you don't tell them where it is hidden.
riversong,
The more we discuss this the more variables enter and to put those in perspective I keep referring to my own house.. I apologize for that..
So briefly if you ever go to Europe or look at European timberframes you will see the timber structure on the outside but not always on the inside.. Here in America you see timbers indoors but seldom on the exterior and then usually only around the entry..
My home has timbers both inside and outside with SIP's squeezed between. In retrospect I wish I'd used ICF's instead.
In order to ensure the maximum durability I choose wood that is very decay resistant. Black walnut on the exterior and white oak on the interior.. pictures at 85891.1 and 94941.1 as well.
Now back to the issue of living space versus conditioned space.. today our basements are often where the furnace is as well as plumbing and etc.. heat that escapes thru radiation etc. from furnace ducts or whatever eventually works it's way upstairs. Loses due to lack of insulation means that to retain heat the foundation itself must be insulated. Lacking that some heat is wasted warming the ground or around the foundation.. More and more that space is also used for living space.. it may be a shop or Garage (in my case) or a rec room or whatever.. depending on the land around the basement it may even be a bedroom..
Speaking about heat,, you are slicing definitions very thin. The effect is the same heat rises Or we could also say the ground falls away from hot air balloons I suppose..
If Timberframes were as durable as stone is we'd have a lot of 2 or 3000 year old timberframes.. Instead only a tiny handful of them remain over 500 years old. Timberframes can be destroyed by insects, decay, fire, and earth movement..
There were tens of thousands of log homes built 2 and 300 years ago in this country yet only a handful remain from that era and most of them have had major repairs or replacements done to them.. . So how wood is used is critical to it's durability.
Concrete on the other hand isn't nearly as critical.. it won't normally decay or be attacked by insects, fire usually doesn't destroy it and it doesn't rot with simple contact with the ground..
You speak about how foam can be attacked by exposure to UV sunlight.. I might point out that wood does the same thing.. So we take measures to protect the weaknesses inherent with each material. We paint wood, we cover foam we add rebar to concrete..
In better world we don't have any end of life issues with buildings.. they remain intact and simply adapt to new conditions.. Nobody is worried about breaking up the Sistine Chapel or the Taj Mahal. On the other hand few mobile homes last even 30 years let alone hundreds of years.. perhaps we should mandate people live in a beautiful building? Sorry, I use sarcasm when I lack a simple way to say what I'm trying to..
It's complex, insist that all places meet some standard or allow less than excellant in order to provide housing to people who cannot afford excellance..
The fundamental problem is that there are more people living on earth than the earth can sustain..
The fundamental problem is that there are more people living on earth than the earth can sustain..
Now here we agree completely.
But I don't suppose this is the forum for discussing what to do about that?
P.S. I'm not splitting hairs about heat movement. What I stated was precisely correct. And I believe that we humans, who have been given the amazing power of communication, have as much obligation to use our words with as much care as we put into crafting a fine house.Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Riversong.
The internet is tough for people like me.. I'm dyslexic. Finding where they hid the that letter this time is tough.. The only reason I can spell at all is the trick they teach copywriters. That often allows me to use spell check to get the letters in the correct order..Lacking that I search for similar words which spell check will allow me to correct. I define hunt and peck. I am pleased when what I write makes sense, let alone is well crafted..
With regard to heat movement.. you are correct however to make that arguement along with all the others will make every single posting far too long.. I take what short cuts are available and if I don't always meet the exact definition Hopefully the concept is made well enough so my point can be understood..
The fundamental problem is that there are more people living on earth than the earth can sustain..Now here we agree completely. But I don't suppose this is the forum for discussing what to do about that?Actually we've had a couple of threads here on the subject of vasectomies. My company has first dollar medical reimbursement for vasectomies but have never paid out. Personally I think it's one of the best things I ever did (to stop at one) Be wellM------------------
"You cannot work hard enough to make up for a sloppy estimate."
Is it that warm in Lake Minnetonka? The ground temp is the same as the average annual air temperature, which is 42°-44° here in Vermont. But basements obviously get some heat loss from the house above.
Near the surface, yes. But five or six feet underground that temperature is regulated in the northern half of the US at between 50° and 55° annually. Put a thermometer on a basement floor and you'll see.
You're right about heat movement. I learned it as "heat goes to where there isn't any," also known as moving to areas of lower pressure, or higher energy moving to areas of lower energy. All else being equal, the pressure of the atmosphere decreases as altitude increases, so in many or most cases heat does rise.
five or six feet underground that temperature is regulated in the northern half of the US at between 50° and 55° annually. Put a thermometer on a basement floor and you'll see.
Who "regulates" it - the gov'mint?
The basement floor temperature is NOT the ground temperature. The average annual air temperature in Minnetonka is 46.4°F, which will be exactly the same as the constant ground temperature.
All else being equal, the pressure of the atmosphere decreases as altitude increases, so in many or most cases heat does rise.
In EVERY case, heat moves equally in all directions. The movement of heat is by conduction and radiation. In each case heat will move from hotter to colder, regardless of direction.
The only time "heat" will rise is by convection, but it is not the heat that rises - it is the warm (and hence less dense and hence more buoyant) fluid, either liquid or gas. The heat in those fluids is still dispersing equally in all directions, even as the fluid rises.
The average annual air temperature in Minnetonka is 46.4°F, which will be exactly the same as the constant ground temperature.
At what depth? Six inches? Six feet? Six hundred feet?
In EVERY case, heat moves equally in all directions. The movement of heat is by conduction and radiation. In each case heat will move from hotter to colder, regardless of direction.
The only time "heat" will rise is by convection, but it is not the heat that rises - it is the warm (and hence less dense and hence more buoyant) fluid, either liquid or gas. The heat in those fluids is still dispersing equally in all directions, even as the fluid rises.
That's what I said.
"That's what I said."
What you said was: "in many or most cases heat does rise"
Heat does NOT rise. Hot fluids rise. Heat moves equally in all directions.
The average annual air temperature in Minnetonka is 46.4°F, which will be exactly the same as the constant ground temperature.
At what depth? Six inches? Six feet? Six hundred feet?
At the depth at which the ground temperature is constant year round.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Riversong,,
I think what Mike and I are both trying to explain is that the center of the earth is hot.. I mean really hot!
it loses temp as we rise up but even during the winter if you are below the frost line (50 inches here typically at worst) the ground temp is warmed to 55 degrees. That is the basis of earth sheltered homes..
stuff everything into an area that never drops below 55 degrees and it's relatively easy to heat and extremely easy to cool in the summer..
it loses temp as we rise up but even during the winter if you are below the frost line (50 inches here typically at worst) the ground temp is warmed to 55 degrees. That is the basis of earth sheltered homes..
The heat at the core of the earth contributes a negligible amount of heat to the mantle, which stays at approximately the average annual air temperature of each climate zone.
As a caver, I can assure you that this is true. We have electronic recording data monitors underground, and the temperature of Vermont caves is 44°-46° year round.
In Hawai'i , cavers wear t-shirts and shorts. In VT, cavers have to wear long-johns in the heat of summer, and we go into caves in winter to warm up.
View Image
At depths of twenty feet or more, there is no significant change from summer to winter, and the mean ground temperature approaches the annual average air temperature plus 2°F down to about 200 feet.
The reason that Earth-sheltered homes (and ground-source heat pumps) work is that - in winter - the ground temperature is greater than the average air temperature, so there is less delta-T and slower heat loss. The house is NOT warmed by the earth in northern climates.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Frenchy, last night I did a bunch of internet research and apparently Riversong is correct--I read several technical papers and all of them agree with his statement. The center of the earth is hot, but that's not the basis for earth-sheltered homes.
I couldn't find where the 50° average came from--it's been in my head so long it seems like stone hard truth--but I'm pretty sure Robert knows what he's talking about.
Mike,
I'll Have to conceed that as well. That 55degree number is in my head and I have nothing on hand to back it up..
Maybe we got it from Piffin.
Seriously, it must have been at least ten years ago or maybe fifteen that I first heard it, and put a thermometer on an unheated basement floor to test. Must have been an old solar home book I got from my FIL?
Mike,
Nah, Let's blame it on Splintergroupie. she's more interesting <grin>
We could, but then I'd never get a Splintergroupie cribbage board.
Mike,
Face it, your whipped! <Big Grin>
and by a cribbage board no less.......
At what depth? Six inches? Six feet? Six hundred feet?
At the depth at which the ground temperature is constant year round.
Consider me learned.
;-)
"Do you agree that it's the first "green" foundation for a basement? "
No.
A stacked stone foundation would be much greener and has been around for a long, long time.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
How does a stacked stone foundation resist uplift?
In terms of embodied energy content and resource conservation there are very few steel building systems that qualify as green.
Even if the steel is 100% recycled from a plant withing 300 miles shipping distance of the construction site there will always be better ways to use that resource such as re-manufacturing it into vehicles or infrastructure that cannot be built from wood or concrete.
For a green panelized foundation system look at one of the pre-insulated Superior wall type products with a low VOC adhesive at the joints.
Alternatively one of the Insulated concrete form systems like poly steel 3600 with the borate treatment in the foam to stop termites is a good alternative.
Just remember that concrete is only green if used conservatively. No benefit in pouring a 10 inch wall if three will get the job done, this is where the Superior wall system shines.
m
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"You cannot work hard enough to make up for a sloppy estimate."
Hold on a minute, Superior Walls have steel studs too. Why would you use a product that has steel and concrete when you could use one with steel only? (and a lower price and lower shipping costs)
Fair enough but we have two competing superior wall type plants making panels locally from local concrete and gravel. I don't want to get into the dis-assembly and re-use of my building components s at the end of their life cycle, I prefer to think they will be remodeled and occupied long into the future as homes.------------------
"You cannot work hard enough to make up for a sloppy estimate."
I like the way you can get a LOCAL company to come out and form the foundation walls out of re-usable forms with LOCAL workers.
The concrete comes out of a LOCAL plant that gets it's rock out of a LOCAL quarry.
I also like concrete foundations. They are really strong and last a long time.
If you talk to the locals they have stories about the quarry, the concrete plant, and who builds good foundations. It's all interconnected.
Connections with your surrounding area and the people that live there is as green as it gets. It's not about the product really.