Hypotheticals won't keep you warm at night, Dragmit. You are still missing the significance of my "irrelevant" variable. Any storage scheme involving sand or stone starts by tossing away 80 percent of the available btus. I am storing heat overnight in a concrete slab anyway, but its inefficiency doesn't matter. Passive solar is free, and for gray days, so is firewood in my part of the world. I need windows and floor regardless; the stove cost $2,300.
Where is your cheap energy? (and I don't mean hypothetically speaking.) You keep on about building the garage. Shouldn't you working on the car?

Yep- even using a high degree of vacuum for insulation the delta-T & surface area will induce radiated heat transfer.  The heat loss can only be mitigated, never eliminated with insulation, and the transfer will always increase with delta-T & surface area.   It's very basic physics- no high math required.

Hi Alton. Sorry, I forget to put my name in ... sort of. Dragmit spelled backwards is Tim Gard. And you are correct. But then the question is, which continues to cost money, natural gas or insulation? If you let the heat leak out then you must continually replace it. And the price of this stuff isn't coming down, ever. But stop the leaks and the heat will sit forever. Or at least until you take it out. Lets say we have an R factor of 30 with 6 inches of fiberglass insulation. If I add sheet rock and another 6 inches, (12 inch total) does the r factor double? Owens says it does. Does a 6 foot thick wall then increase 12 times the r factor? What about alternating fiberglass and dirt? The dirt has a high r factor, and the insulation would stop heat loss due to air circulation (convection). You see, while you guys have always had to deal with wall space as a factor, underground we can put in whatever we want because the space has no other function. Above ground I could build 40 foot thick walls that would never let out a speck of heat, but I would be dead from suffocation. Warm, but dead. Underground? How thick do you want it? Until 350 degree heat can no longer pass through? Do you think this can not be done? And why not? But lets face the real truth here Alton, the only real cold you'all see there in Alabama is the occasional mint julip! But I got no rattlers! (My Mom was from Memphis family from Alabama.)

Hi Dana,

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That’s not basic physics, that’s boxed cereal. Aim Higher. I do not intend to reach perfection, but if I use that as a goal, and try like hell to get it, then I should have a pretty good shot at something better. You see, you guys always have a reason for not doing things. Its called being a self defeatist and ordering from the Sears catalog. I prefer to try to reach beyond those limitations without automatically accepting the status quo. Like the disease called "Basic physics" when its really not. And math is always required. Even in a simple bank shot in billiards. Take a chance guys, you are the best and the smartest at these things ... cut it loose and think outside the box! Sorry to be so hard on ya.

As a side note, I'm not trying to sell this stuff, just doing a bit of R&R. You would be nuts to take the discussions here and try to sell this product to the consumer. I have no intention of doing that. But if we do come up with a viable system, well that changes everything.

Hey Todd,


Yes Todd, the 80 % might be attainable, but you must look at the mission, not the color of the paint. But, following your statement ... I believe that if I start with a 250 degree rock, and I circulate 100 degree water through it until its temp drops to 80% or 200 degrees, I can still get the 100 degree water up to 180 degrees on the next cycle, so 80% does not make sense. How did you come up with that number anyway? By the way, I trained the horse first, then I built the barn, then built the car. Doing the car first is just ... nuts! <;>P Sounds like your getting a bit irritated. Sorry about that.

I'd ask you to explain that last post except for (a) you'd probably try (b) gotta go. Taking your sermons to heart, I am assuming that Angelina Jolie will ring my doorbell any minute.

Thanks Alton. I too am a professional student. If you don’t mind, keep an eye on this thread. Challenge what I write. Ask questions. Point out errors. Any research I have ever done required deep thought, research and many mistakes. That goes for anyone following this thread. I welcome challenge that inspires thought. Edison could tell you 250 ways not to make a light bulb, why should you and I have to do better? But Tesla? Now there was a thinker ... except for that thing he had for pigeons ... and turbines. A fair warning however, I make fun of Tesla, Edison, and even our paperboy. It is not to be mean, it is just friendly teasing. That is hard sometimes in email, but if I say something that gets under your skin, take it with a grain of salt and plan revenge! (Like my friend Todd above ... I think my freewheeling tack ticked him off. Sorry Todd, didn't mean to get under your skin.) Like I said I love a challenge! And a fight! Damned Irishmen, or Scotsman, or English, or Swedish, or whoever the hell my ancestors played with ... My nationality is Heinz 57 variety! See you in the funny papers.

Sure it's basic physics, and yes, doubling the thicknesses pretty much doubles the R value and 12x is 12x. If you're going to be cycling the temps you need to factor in the specific heat of the various materials and do a time based model on your temperature swings, which makes the math a bit more complex.

Dirt has a high R factor? Since when?

Heat transfer in soils is a very messy topic and R factors vary with both humidity and temperature. Soils also vary widely in specific heat, but are reliably much lower than water. The PassiveHouse Institute has developed reasonable models of heat transfer in various soils- mayhaps you could buy their software and monkey with it a bit to get a better feel for it. But there's a REASON they typically use several 10s of R value of foam insulation in their foundations in cool-soil areas, and that's to limit the heat loss from the conditioned space at very modest temperatures & delta-Ts compared to water at even domestic hot water levels. Heat loss to the soil IS calculable/model-able, but the fundamentals don't change- it's still a function of surface area and delta-T in a static model.

IIRC there were some folks in OH building arrays of large insulated undergound tanks for thermal storage starting with 1000-1500gallon septic tanks and applying several inches of 2lb foam before burying them. You may be able to google it. They were calling their concept "seasonal flywheel" or something, buffering large amounts of solar heat in multiple tanks to be able to utilize it for space heating going well into the dark winter season, calculating it's depletion to coincide with the higher insolation of late winter when the solar array could again keep up with the load.

Oh, Todd, just thought you might want to know, Angelina Jolie is my niece! She'll be over next week for dinner, want to join us?

>Dirt has a high R factor? Since when?

Yikes! Sorry about that. I should be careful about what I say. You are of course correct, dirt can have a really poor R factor, especially if it has any moisture in it, and if its in the ground its wet. It will suck up heat like a sponge to water. Thats exactly why I wanted to moisten the sand internally in the tank. My interest in deep insertion is not for dirts effectiveness as an insulator necessarily, but because the atmospheric conditions have very little effect on the energy levels in dirt 30 feet below surface. But it does insulate, especially 30 feet of it! I have considered finding a way to dry and keep this earth dry, but I but that would be tough. Its not off the drawing board yet though. This ground temp 30 feet down is pretty much fixed at 50 some odd degrees here in NY. That 30 feet of dirt insulates this ground level quite well from our 20 degree days here in the winter. I have to contain my heat primarily with some other type of insulation, and having and a constant 50 some odd surrounding temp will help. That is my r factor in dirt.

I didn't find the Ohio project you spoke of Dana, but wow! Ha! Here it is in Wikipedia! I knew this was possible! Now, how far can I take it. Zero heating bills? Come to Papa!!

Seasonal thermal store
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[edit] Low-temperature seasonal heat stores
One of the original motivations of early man's movement into caves was probably the ability of the earth to naturally even out variations in temperature. At depths of about 20 feet (6m) temperature is naturally “annualised” at a stable year-round temperature.

With the development of modern passive solar building design, during the 1970s and 1980s a number of techniques were developed in the US that enabled thermally and moisture-protected soil to be used as an effective seasonal storage medium for space heating, with direct conduction as the heat return method.

Two basic techniques can be employed:

In the Passive Annual Heat Storage (PAHS) [1] and similar direct solar gain systems, solar heat is directly captured by the structure's spaces (through windows and other surfaces) in summer and then passively transferred (by conduction) through its floors, walls (and, sometimes, roof) into adjoining thermally-buffered soil. It is then passively returned (by conduction and radiation) as those spaces cool in winter. These techniques were advocated in Daniel Geery's 1982 book Solar Greenhouses: Underground and John Hait's 1983 Passive Annual Heat Storage.
The Annualized Geothermal Solar (AGS) concept [2] involves the capture of heat by isolated solar gain devices (rather than the building structure). From here it is deposited in the earth (or other storage masses or mediums) adjoining the building using active or passive technology. The depth at which the heat is deposited is calculated (according to soil type) to provide a controlled 6-month heat-return time-lag to the building through conduction as the building cools. This alternative was posed by Don Stephens.
These concepts are compared in greater detail at: www.greenershelter.org.

[edit] Warm-temperature seasonal heat stores
Warm-temperature heat stores are a development of low-temperature stores in that solar collectors are used to capture surplus heat in summer and actively raise the temperature of large thermal banks of soil so that heat can be extracted more easily (and more cheaply) in winter. Interseasonal Heat Transfer[3] uses water circulating in pipes embedded in asphalt solar collectors to transfer heat to Thermal Banks[4] beneath the insulated foundation of buildings. A ground source heat pump is used in winter to extract the warmth from the Thermal Bank to provide space heating via underfloor heating. A high Coefficient of Performance is obtained because the heat pump starts with a warm temperature of 25°C from the thermal store, instead of a cold temperature of 10°C from the ground [5].

[edit] High-temperature seasonal thermal stores
High-temperature seasonal thermal stores are found on a variety of scales, from those installed in individual houses to those serving neighbourhoods via district heating.

If you are willing to scrap your radiators, combining storage and ground source heat pump is an intriguing idea. First, you'd get lots of capacity at reasonable temperatures. A max temp of 140 is doable for conventional solar hot water. (Iif you stood the tank on its end, you'd get great stratification.) Storage could contribute down to 60 degrees. With an 80 degree delta T, your tank would store 6.4 million btus. But that would be a pre-heat pump figure. Using a blending valve to deliver optimal temperature, you could magnify storage by 3 to 4 times, or 15M btu to 24 million btu. The array would continue to add heat through the winter, and this btu stream would also be multiplied by the heat pump's coefficient of performance. You'd calculate how much collector surface you'd need to generate 6.4M btu through the summer. You'd size the pump and ground loop accordingly. Just eyeballing it, I'd get half of my heating load for free* in a smallish efficient house, and the other half at geo's attractive COP.
*The capital cost could be a very large number.

You'd need a tiny air conditioning load. You'd need a large and economical backup. (In a bad winter, you wouldn't want to be reduced to a cold tank and a severely undersized heat pump.) Retrofitting ducts or radiant would be expensive and messy. And you should run this by a geo guy, because I know zip about its practical aspects.

I need to consider small pieces at a time. Please explain scrapping radiators?

You used that naughty word ... conventional. By using magnifying glass I can easily reach much higher temps than 140. Remember, I have 6 months to allow fluid to heat under glass. And if I must, I can build more glass to speed things up. More heat, more energy. Your thoughts?

Also, how much would the value of a house go up if you never had to buy heat? That is what would offset the cost of a passive system like this. As soon as I start adding heat pumps the electric bill goes up. Remember, we are trying to avoid the status quo. There are more questions about your post, but I will come back to those. Oh, and yes, until proven I would not remove my furnace. R&D means Research and Development, not Raging Dummy!

First unfortunately you can't perfectly insulate a room to not allow it to gain or loose heat to its surroundings. But assuming you could the answer is simple, it would be warmer. If the fridge is consuming 250 watts to run and it ran for two hours the space would be 500 watts warmer (1700 BTU’s) as well as the heat extracted from the interior of the fridge. The interior of the fridge would be way cooler than 33F if it ran for two hours. A fridge is just a heat pump moving the heat from inside the insulated box or the inside of the fridge to the exterior of the fridge and warming the space it is in, in this case a sealed space.

Unfortunately, you may fine that it is worth less.  In any case, the universe of potetial buyers will be reduced.   While your system may appeal to green, nerdy, DIY tinkerers, I think think it wil scare a lot of "mainstream" buyers.

My €0.02

Bruce

Correct Brock! And once you see that, it is obvious, no? If you ask most people that question face to face, quick thought leads them to believe the room temp will drop. But, if you cause people to take the time to think about it, they usually figure this out. If you take time to think about these things, you will find the obvious answers are not always right. Because we are not combat pilots, we do not need to make decisions that fast, so we can take the time to mull things over, and we should. Thats the key to research. I am constantly taking points I have 'learned', reinserting new data, and rethinking them. I sometimes find it hard to believe things can be radically changed so much by so little, but look what a few dollars of frozen water can do to a 2.5 million dollar aircraft! Variables guys, dont forget about the variables!

Another research point. Never begin a thought with 'you can't'. We know this, but if we fail to attempt something because we attached this phrase too quickly, a key could be missed. This is what I mean about shooting as high as you can. Now, in regard to this, something like zero energy loss may be unattainable. But that is only with the knowledge we have. There were people out there who truly believed human flight was impossible. Its a damn good thing others refused to listen to that 'you cant'. As soon as you say you can't, ... you can't. Your finished. But only because *you* developed that limitation. Try 'maybe I can ... if ... ' I need you guys man, dont freeze.

My mission is not to lock up this energy with zero losses, only to work towards zero so I never stop looking for something better. I can not stop trying. But we must not loose the information gained in the attempt. This is the real prize!