Sand for Thermal Energy Storage

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Discussing the idea of sand for thermal energy storage of heat for months intended for household and greenhouse heating in cold climates that get a lot of sunshine. I discuss the idea of sand verses water for heat storage and look at the different instalation aspects like piping, insulation, and solar collection from parabolic troughs and concentrated solar.
Chapters:
00:00 Introduction
01:51 Household Energy Usage
03:03 Solar Collectors
04:41 Sand Heat Storage
05:11 Air Crete Insulation
05:56 Types of Pipes
07:00 Water Containers
07:35 Delivering Heat
08:45 Liquid Heat Delivery Options
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22 май 2024

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Комментарии : 1,8 тыс.

@SimpleTek 3 года назад

I need your input on piping, insulation, and distribution of heat for a sand battery! Help!

@tonyarnez5193 3 года назад

From what I saw, they don't even use steel pipes, I think they just used flat rocks, steel furnace pipe would probably rot out fast.

@jeffstout6567 3 года назад

R50 is zero energy from a starting point. Fiberglass, foam and air Crete.

@SimpleTek 3 года назад

@@jeffstout6567 nice

@dvr102 3 года назад

maybe lower temperature, but a bigger area with sand?

@SimpleTek 3 года назад

@@dvr102 that's possible

@MichaelJohnson-jt5cu 2 года назад

When I worked in the Solar Industry decades ago we used a saturated water/salt solution that would turn solid at room temperature and turn to liquid when heated. This liquid was stored in plastic stackable trays stored in an insulated room, air flowed through the trays to charge them with heat or extract heat at night using a conventional HVAC duct system in an attic or space for the thermal heat storage.

@SimpleTek 2 года назад

Interesting! Thank you for the comment!

@brianevolved2849 2 года назад

any chance you can give us more details

@SuperJLTube Год назад

Phase change material. I wanted to use a layer of this in my design

@AlxGontijo 8 месяцев назад

So interesting! Awesome! Can you share any technical information about? Any financial information?

@Kontorotsui 8 месяцев назад

What salt?

@MinnesotaBeekeeper 2 года назад

Minnesota. We worked on one house that stored their heat with 1 inch riverstone instead of sand. Never thought about it before but the stone would allow full airflow from the heat source. Eliminating piping. Hum. The stone was in insulated below ground bunkers.

@SkySailor75 Год назад

Interesting. I just bought a property where they pushed the old stone house into a hole, so I definitely have the stones to do this.

@off-gridsurvivalmike8120 Год назад

Great concept, I am building prototypes now for demonstration and to work out the bugs. So your idea of the larger stones will work great. So my thoughts are to have a heating element buried in sand at the bottom of a barrel or some container and now I will add larger stones at the top with maybe some grating between the two mediums at that point I won't need internal piping, like you said the air will flow around the larger stones. Perfect, fantastic commen.

@TheGijzzz 2 года назад

Here in the Netherlands there is already an housing project that uses a big isolated basalt stone mass as an heating battery for heating in the winter. During the summer regular solar panels collect electricity that is stored with piping as heat is the basalt. In the winter this stored heat is used to heat a whole housing block ( name of the project: cesar-project and basalt-batterij)

@SimpleTek 2 года назад

That’s awesome thank you for sharing

@joergsonnenberger6836 Год назад

In Hamburg Siemens-Gamesa has an upscaled grid-level version of this using basalt as well: ETES, it can store 130MWh of heat in about 1000t of stone.

@AlxGontijo 8 месяцев назад

Really nice! That's idea is really awesome... Do you have any information about the ROI of this? Any financial information?

@AlxGontijo 8 месяцев назад

@TheGijzzz

@nicolasp6198 2 года назад

let's do a little bit of math here. before that I just want to point out that water usable working range is closer to 30-90°C rather than 60-85°C. With 30°C water you definitely can heat a room equipped with a costly heating floor OR more smartly a fan-equipped water radiator to replace old high temperature radiators. For water, this gives a DeltaT of 90-30=60K So the volumetric heat capacity for water over that range is E(water)=Cp(water)*rho(water)*DeltaT(water)=4186*1*60=251kJ/L Cp being the thermal capacity in J/K/kg Now for sand : E(sand)=Cp(sand)*rho(sand)*DeltaT(sand) So if we want E(sand) > E(water) we need DeltaT(sand)>251kJ/Cp(sand)/rho(sand) Google says rho(sand)=1.6kg/L and Cp(sand)=835J/K/kg This gives DeltaT(sand)> 187°C Since we took a minimal working temperature of 30°C for water we need to take the same for sand which eventually gives a minimal heating temperature of 217°C. Now we need to remember that at this temperature sand is just as good at storing heat as water is in a given volume. We need it to be a lot better to compensate for its inability to be easily pumped like water. Let us asume that we want sand to be 30% better per volume unit than water. Then sand will have to be heated at 273°C. This means that our free heat source will have to be at least that temperature, which is clearly not that certain for domestic use. The only places where sand can be heated continuously over 250°C is in those concentrated solar farms where a thin curtain of black sand falls across the supper bright focused hotspot on top of the tower. On top of that, those temperature are very close to the auto inflamation of most materials like wood, dust, plastics, etc. So the fire hazard would be extremely high in residential use. With all that said I think that, for domestic use, the better way to consume less wood throughout the year is to throughly insulate your house, use a heat pump that only work during the daylight and store the daily heat in a water tank or a massive wall or soil using simple PEX tubes, it is less sexy (I love exploring tech ideas too...) but it is a long term solution.

@SimpleTek 2 года назад

Thank you for all the detail!

@nathanielmccormick7230 2 года назад

Hello I'm an hvac journeymen. I believe air is your best medium. Using soft copper you can store heat in your sand. Then when you want move your heat from the sand with air to a tube in shell style heat exchanger. A tube in tube heat exchanger would work as well. You then can control water temp by simply controlling flow rate of air around the water tubes. And from Here you have your radiators and such.

@SimpleTek 2 года назад

Interesting

@keithduffield5239 Год назад

Agree - instead of sand the medium can be small granite rocks and you heat air in the parabolic reflectors and discharge at the bottom of the rock pile. In a closed system with non-return valves I am sure circulation could be done with convection/Pressure difference flow.

@davidhoff3829 Год назад

I would also be in favor of the air return. This should be the cheapest option.

@shanewestphal1557 Год назад

I was a boilermaker specializing in heat exchangers with high temp, high pressure. I agree with your answer, was thinking the same thing essentially. Any liquid you use with a high boiling point is going to be expensive and/or and pressure. High heat and high pressure is not safe for most people and expensive.. A combination of water/air/sand would be relatively simple, diy friendly, low maintenance, low pressure.

@mrogormand1 Год назад

@@shanewestphal1557 I've been thinking, would it be possible to remove the burner from a domestic gas boiler, and just feed hot air from your thermal battery to the heat exchanger instead? What would the air temperature at the heat exchanger need to be to make this viable?

@thebandplayedon..6145 2 года назад

So far, I have my greenhouse pit dug, aprox. 5' deep. After insulation with ridged foam I plan on filling the floor in with two feet thick adobe/cob slab, then add another foot or so on top of that but with a 6" diameter channel running thru it to direct and collect heat from a woodstove before heading out thru the chimney. This will operate similar to a cob bench often attached to a rocket mass heater in a home. Only requiring a very minimal amount of wood and effort in the day/evening to create enough radiant heat to get thru our cold Canadian winter nights. And, in summer, the cool floor mass will help regulate the interior temps with at most a dc fan for circulation. I've come to appreciate systems with as few movable, motorized, and electrified parts as possible- less to break, more reliable, easy/free to DIY fix, etc.

@SimpleTek 2 года назад

sounds awesome!

@billdevany3303 Год назад

I love that you have more questions than answers. It breads intelligent conversations and innovation from the "crowd". there are more intelligent and well thought out responses in your comments that I wont even through in my two bits. keep us up on how it goes.

@SimpleTek Год назад

Soo happy I could confuse you

@MikeH-sg2ue 6 месяцев назад

Hi there, as a Canadian, I understand how sand is a nice thought in the Winter! Tahiti has some lovely sandy beaches! I am very interested in sand batteries. In the past I’ve done a couple of small scale experiments. In buckets, & large SS saucepans. Bought 3 older electric kettles from thrift stores. Hooked directly to a 100w solar panel. They all worked. The bucket worked best, but I was concerned about heating the galvanized bucket that hot in the house. Fumes might be an issue. The saucepan worked well, but wasn’t big enough. After watching your video, I now have a bunch of new ideas! Who knows what I’ll come up with? Keep your smiles on!

@SimpleTek 6 месяцев назад

That’s awesome!

@yellowbird5411 Год назад

As a primitive heat storage for those who have had to use this method throughout history, rocks and I imagine, sand, would hold their heat for long periods of time. I am thinking of the very old fashioned methods of heating specific areas with hot stones, heated by a fire, then transported to where they were needed. They not only used them for heating beds in freezing bedrooms, but also in outdoor carriages, under the seats, and in their homes where needed. These rocks would get switched out for newly heated stones brought in from either outdoor fires or indoor fireplaces. In this day of fuel shortages throughout many parts of the world, it seems we must inform ourselves of lifesaving methods of survival. When the weather thrust Texas into a deep freeze a couple of years ago, it was reported people froze to death, and pipes broke from freezing also. It seems the electric was down in many areas, and people apparently were not able to stay warm. It pays to know basic survival techniques, and sand used for heat storage makes sense to me. I had been thinking of getting stones, as in Florida we don't have "stones" as much as limestone, inland. But I thought of sand as an option, because if nothing else, Florida has all the sand one needs. Of course, it is mixed in with organic materials, but it is not hard to wash sand to the pure white state. I have done that. Once that is done, dry sand should be good for heating by the fire outside in metal containers that can be safely moved indoors to a metal or fireproof platform to warm small areas, should our grid go down. We dip down into the 30's here, and while no one would necessarily freeze to death, it can get very bitter during the nights, with days usually in the 50's. Thank you for this video, and I just wanted to recognize sand as a great potential heat storage/insulation resource.

@SimpleTek Год назад

Great info

@zeoxbg 2 года назад

I would say that electric heaters, fed by photovoltaics are a great way to store a lot of heat in a closed and well insulated sand container, that has built in pipes for heat exchange. You could easily get the sand to 300-400 degrees C. Stainless steel should be a good material for the container/heat exchanger. Insulation should be very good, maybe a first layer of perlite/cement, second layer of hempcrete or rock wool (or maybe both). And the whole thing put underground. Using a loop of high temp oil, you can easily transfer heat from the sandbox to a water boiler. And relying on photovoltaics, rather than solar heat collectors, means that even in very dim and short winter days, you could get at least some heat. And in the summer you can use the extra power for other stuff.

@SimpleTek 2 года назад

interesting

@paullehto2294 Год назад

Check out Finnish company polar doing it

@t9358 Год назад

Thank you for post. is high temp oil vs high temp air better and less cost. i think Polar Night Energy does hot air and thought it strange

@zeoxbg Год назад

@@t9358 Hot air is a nice concept too. But I think it would be harder to achieve as a DIY project. High temp oil can be achieved very easily using old water heater tanks, copper or steel serpentines... Basically junk that can easily be obtained.

@Ed_Stoddard 3 года назад

I created a scaled down version of a mirror concentrator from a Mother Earth News article in the mid 80's. I used a 10 x 10 array of 12" x 12" mirrors that tracked the sun using simple photo voltaic cells, a relay and a car starter motor to maintain focus on the sun. I raised our 24' above ground pool by about 17 degrees F. I only tracked across the sky and had to adjust every couple of weeks for longitudinal changes. Adding a second motor and sensors would be simple, especially with arduino systems available. I like your idea of using oil instead of water to avoid the thermal limit that steam introduces. The article is entitled "Make a Solar Furnace" under the renewable energy category. Using oil instead of water through a system like that would give you the temperatures you are looking for. Using oil in the trough design would allow a simple thermal gravity flow if aligned right. The cost of mirrors like the article do add up quickly. Keep us up to date on your plans. I like it.

@SimpleTek 3 года назад

Thank you for the info! I enjoyed that!

@danf4447 Год назад

how did you build or make the frame ? strength..windproofing..allignment?

@unclepete100 2 года назад

Use the heat stored in the sand to heat air and pump the air to the dwelling / greenhouse. Eliminate the complexity and expense of liquid handling altogether. Used aircon ducts are usually available in metal scrapyards. Cheers

@SimpleTek 2 года назад

I like it

@frankfrederick5158 2 года назад

A little simplified, but the sand must be heated first. Then the heat can be distributed. Air alone will not create enough heat in a compost pile to heat the sand/rock bed uniformly. Also taking too much heat or a a fast rate from the compost pile decreases the amount of "energy" created. Distributing heat via an air plenum also lowers the efficiency and is adequate for a small confined space but not a larger area. Think "Rocket Mass Heater" concept but will a large mass heat storage area. My greenhouse is 30' x 60' and I will be adding hydroponic growing space next year.

@shaun6828 2 года назад

@@frankfrederick5158 Air doesn't create any heat. It's just a medium for transporting it. Move the air and you move the heat energy it contains. Works pretty much the same as with fluids. Fermentation inside the compost pile will produce heat, but only a small amount. You can extract some of that, but if you take too much, the fermentation process will slow. Air would work fine for warming sand just like any typical household heater or heat gun does. The issue, is having enough input heat to charge the battery at a rate faster than it loses heat. Even with insulation, heat will be leaking out of the battery.

@frankfrederick5158 2 года назад

@@shaun6828 Thanks Shaun, I do believe we are saying the same thing, just in different ways. Your comment on fermentation is correct. I might add it take "air" to create the fermentation process. Starve the process of air, deplete the fermentation (heat) created. Also, for the compost pile to last (up to) 18 months small mounts of water, air, and bio digester are added regularly and the pile "turned" to help the process complete.

@shaun6828 2 года назад

@@frankfrederick5158 I saw a video of a farm that used sealed tanks for the process. They tapped it for methane emissions. I guess it also depends on what is being composted, but ethanol is another possible byproduct...

@pjcdm 2 года назад

Love the channel and your goals. Ya! Making it for cheap is the biggest problem and requires genius solutions. Hot tropical climate here. I need cooling ideas. I have seen the tube in colder water video. I will think and come back with ideas.

@SimpleTek Год назад

I have videos on cooling! Thank you for the kind words

@pjcdm Год назад

@@SimpleTek love that one: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0N61DwS6PpU.html

@georgeyjungle 2 года назад

Build the sand storage box with an air gapped insulated compartment on top and control the temperature of the air so that you can heat a closed loop water system directly via salvaged radiators or copper pipe. You may need an exhaust in the air box as protection to prevent over heating of the water.

@SimpleTek 2 года назад

interesting

@patrickforbes6745 Год назад

Air is probably the best choice for moving the heat into the sand. I’m looking to build a rocket stove and blowing cool air with a small fan across the top in a 4” pipe and then down into the bottom of the sand. The pipe then splits out as a manifold into smaller pipes that have holes in their bottom so the air can get into the porous sand. A similar manifold at the top could bring warm air to where it is needed.

@SimpleTek Год назад

That’s awesome

@palipali4264 Год назад

Make sure to install a good prefilter or in about ten years your entire intake area will be clogged beyond use. Dust is insidious!

@SimpleTek Год назад

@@palipali4264 wise words

@lynnebalzer6689 Год назад

We have a fireplace insert with a huge fire pit - so large that when we fill it with wood, things get too hot, and there is a risk of chimney fire. We came up with the idea of putting large concrete blocks in the back. They will heat up from the burning coals, and stay hot for a long time. Two fans will blow this heated air around the house.

@SimpleTek Год назад

Thermal mass!!! Good idea

@ulfcarlfinnes2820 Год назад

In Sweden, for many decades, they have made and used tiled stoves that are made of ceramic tiles according to a certain system that forces the smoke to make a round trip inside the stove before it enters the chimney. These stoves are only fired up once a day and they slowly give off their heat during the day and night.

@SimpleTek Год назад

very cool!

@enigmaapoc403 Год назад

Are you talking about "Rocket Mass Heaters?" I've been looking into those quite a bit. I have several project ideas inside and out that I'm planning; from cooking to space heating.

@SimpleTek Год назад

@@enigmaapoc403 rocket mass heaters work great

@robertunderdunkterwilliger2290 Год назад

@@enigmaapoc403 en.wikipedia.org/wiki/Masonry_heater

@garyweber6413 Год назад

that's great in all but the whole idea is to never have to feed that god dam wood stove anymore

@frankfrederick5158 2 года назад

Radiant in floor heating also ups the anty. I have using a compost pile heater in the cold, cold winter for a greenhouse using radiant heat. Going on two years, it has served me well.

@SimpleTek 2 года назад

Thanks for sharing, that's awesome!

@alastairbolland6467 2 года назад

I am looking into this at the moment. Can I ask what size the pile is and how you extract and distribute the heat? Cheers.

@frankfrederick5158 2 года назад

Look at "Compost Pile Heat" here on RU-vid. The videos should answer most of your questions. I use a water based system (twice), one loop of actual water for use in a hot tub and other areas, and second with a glycol mix for radiant floor heating. My in floor heating system is not a normal radiant floor. I did the usual insulated base of gravel/sand/insulation then the in-floor tubing run and covered that with sand, then 2" of concrete. I have a small "boiler" for very cold nights and the usual manifold and pumps. A water heater tank (large) serves as a reserve tank for the hot water. AT a -30 F temp outside over winter, the inside greenhouse temp was 68 F.. Although a bit of trouble to create, my energy costs this year were next to nothing. Summer ideas include a better hydroponic system and an HHO generator for electricity/heat/cooking/cooling/pumping/etc. Good luck.

@jeffstout6567 2 года назад

@@frankfrederick5158 what inlet and outlet temperatures were you able to maintain throughout the winter months. Usual infloor supply temps are 110 degrees F and 90-100F outlet for residential, garage and commercial bldg. what’s your thoughts using your compost heating system.

@frankfrederick5158 2 года назад

@@jeffstout6567 Thoughts? No. Facts, Yes. Average 108 to 114 degrees F into the system. Out between 80 and 90 F. It gets cold where I am - VERY cold, so the floor can suck up a lot of heat.

@1202Sid 2 года назад

I'm Canadian situated in Quebec and I've been looking into this for a long time. Like said before we need to follow the KISS principal. I think that using a heat pump to move heat from a lower temp source to a high temp storage might be the way to go. I'll be looking at a 4 port system soon where I can use 2 ports to store/retrieve heat from the storage and 2 ports for house HVAC. Might be even better with only one circuit to control heat transfer both ways from the battery.

@SimpleTek 2 года назад

great ideas!

@donalddalley7274 Год назад

Depending on the amount of storage mass, a heat pump is going to, typically, manage low temperatures. The advantage of sand is that it can deal with very high temps. The greater the mass, the higher the temps, the greater the energy storage capacity. If you have a well sealed house with in-floor heating, the demand for space heat may be low. Water heating is different.

@1202Sid Год назад

@@donalddalley7274 Of course, for maximizing the low limits.

@randallross6286 2 года назад

Transfer the heat from the parabolic collectors with air. It's free and no need to worry about leaks. Keep the blower fans on the cooler inlet side. Water coils in the sand can transfer heat to the house. The collected air from the top of the thermal sand storage can flow through the greenhouse before is goes back to the solar collectors, or just circulate the warm air to the greenhouse on cloudy days. Water coils in the hotter parts of the sand can be used to power steam generators for electricity.

@graveseeker 2 года назад

That eliminates the 'rainy day' backup that the sand provides.

@SimpleTek Год назад

@johanventer5730 Год назад

Good idea with the steam generator for electricity

@FoodForThought. 2 года назад

Brand new subscriber. Thanks for the videos as I'm looking at building a small urban solar greenhouse in Woodstock Ontario to extend my growing by a couple of months (3 if I can grow 6 weeks early and 6 weeks later). I look forward to getting more ideas from you. Eddie.

@SimpleTek 2 года назад

Thank you for the kind words!!!

@jarrettvick4571 2 года назад

Got this figured out already. I’ll be sharing it on my RU-vid channel soon.

@SimpleTek 2 года назад

looking forward to it

@jarrettvick4571 2 года назад

@@SimpleTek by the way, not a challenge, it’s like you say, when we share everyone benefits. I saw some guys on a video a couple of months back discussing this on a large scale for cities. This was not the first. However, it is the first one I saw on wax. Interesting! They heated their sand to 700 degrees centigrade and emphasized the sand had to be dry… huh?? I’d think it would be dry!! Read some comments below…. It was the Finland group I watched, refreshed my feeble memory!

@justinweatherford8129 2 года назад

Yes, the sand would have to be dry for systems that get even close to the boiling point of water. If it isn't enclosed then rainwater would steal some of your heat in the evaporation process. If you had an enclosed system that had wet sand, then you better have a pressure relief valve to vent off the pressure created by the water that you left in there. That water in your enclosed system would take care of itself over time, but why risk the damage to your thermal battery?

@hotrod7696 Год назад

You can use black steel pipes with fiberglass insulation and for the temp regulation you can use a mixing valve and a heat exchanger from oil to glycol. Great video, thanks.

@SimpleTek Год назад

Thank you for the ideas and kind words!

@smjones4238 2 года назад

I am now subbed... I was going to try synthetic oil, can get hot. Have always wanted to use a trough collector. Need auto adjusting capability however, Bright days can call the fire department. In and out loops into sand use the oil. Run thru a plate to plate exchanger to loop in the house. Pump the water in a loop thru the coils in the house. Use 3way valves so loop is always flowing. Have a 3 way mixing valve on the water side of the exchanger to keep loop speed up while adjusting the percentage of hot water to recirculated water. You could probably even pipe the sand/oil side of the plate to thermo siphon when the demand is low, but have a boost pump in the circuit. Random thoughts: Might want to check the stratification of heat in a big pile of sand. You might use the coils and pumps that introduce the heat and take it out to recirculate the heat by pumping the top coil through the bottom one to keep heat saturation fairly equal. Heat always gets away at the top. I'm sure that you can see that I'm a controls guy. Retired from 30 years of being paid to be a control freak. I also ran the Building Management System where I was. A LOT of analog mixing control stuff with fussy people that like their offices just so. When you put in a lot of control, you can either make it work or it will SHOW YOU the weak spot. 70yo retired with 65yo wife on 2.3ac 45mi ne of Metro Denver limits. 35X70X25 shop just gettin 'restarted'!

@SimpleTek 2 года назад

interesting!

@taith2 2 года назад

I've been researching subject for long time, use ceramic medium, best guess is chimney prefabs. Use nitrogen as heat transfer medium and air turbines to move heat around, can place turbine on cold side. I'm aiming for temperatures reaching 700+C here, borderline stainless steel heat, because it's in later parts in my project where stainless is inevitable at one point of it. Liquid salt and liquid sodium is too corrosive, for your small scale I'd suggest using nitrogen as neutral medium. Can use existing evacuated tubes and parabolic mirrors. For your use best is steel water pipes that are stick weld and have nitrogen running trough it. Obvious side note, you need air pump engine well separated from blades and any regular bearings.

@SimpleTek 2 года назад

very cool!

@youssefdarwich6576 Год назад

Love the thinking here. Check out Curtis stones passive solar greenhouse. Insulated packed sand with air tubing running underground. Takes hot air from greenhouse pumps under ground, cooler air comes out. Inverse in winter. Would be interesting to combine liquid lines underground

@SimpleTek Год назад

Curtis Stone does amazing work respecting ROI on everything EXCEPT his passive solar greenhouses. It works, but it could be built for 1/6 or less the money and do the same thing. He’s aware of that and says it though .

@DaveBuildsThings Месяц назад

After reading many of the comments, my 2 cents for what it's worth. If you have enough sand in a sufficient volume and insulated then my thought would be to use a copper tube coil buried into the sand at regular intervals. Copper has a melting point of 1,085 °C so the temperature would not affect it so long as it was as solid run. (No solder) I would make the size of the piping about 1/2" to 3/4" to maximize the contact area. A simple blower system can be used to push the outside air into the solar collector and feed the heated air into the pipes buried in the sand. No need for a special air pump as it only blows the outside air in and not the warmed air. Also, if the sand temps are right you could use a few peltier wafers to utilize the heat to run the air pump after the mass has warmed. Peltier wafers or chips are used in thermoelectric coolers. When these wafers are powered they transfer heat from one side to the other, which side the heat or cold goes to depends on the DC polarity applied to them. That's why they can also heat the contents of a cooler. But if they are heated on one side and cooled on the other they produce electricity and maybe enough to run an air blower if combined in a large enough scale. Think wood stove fans with no battery that run on the heat generated. That's how they work. Electrical generation was the intent in their original design. The cooler/heater part was found out later. My idea would not be a fast transfer of heat but in IMO it really doesn't need to be if you're collecting heat throughout the day, week, month, etc. Super efficient? Maybe not 100% but I figure it's a good starting point. Thanks for getting me thinking about this. It might be a great way to warm my large chicken coop (24 chickens) in Ontario Canada in the winter. 👍

@SimpleTek Месяц назад

Cheers!

@OyvindSOyvindS 2 года назад

Hello, and thanks for the video. I am planning a similar project. You mention Aircrete, maybe look at foamcrete instead, as aircrete are prone to water permetation and consequently cracking.

@SimpleTek 2 года назад

Thanks for the tips!

@chrismartin2524 3 года назад

Very interesting. Been moving in this direction for a while. Still in progress

@SimpleTek 3 года назад

@edschultheis9537 2 года назад

I believe that the best working fluid for transferring heat to/from your sand battery may be MINERAL OIL. It seems to fit all of your requirements, while also having advantages over other fluids. As an alternative, you may also check into using cottonseed oil or rapeseed oil (also known as Canola oil) as these last two choices are more biodegradable. I saw a couple of suggestions to use water with antifreeze, but that will start to boil at about 226 F (108 C) at atmospheric pressure w/ a 50/50 mix of water and antifreeze. You wanted a fluid that would handle about 300 C. So I don't think this is a good choice. Some facts about MINERAL OIL: > It is already used as a working heat-transfer fluid in products like electrical radiators, power pole transformers and high-voltage applications. > The maximum operating temperature is 316 C (600 F) > Boiling point at atmospheric pressure is 349 C (657 F) > It is essentially non-toxic and more importantly essentially non-toxic to humans/animals > It is odorless and colorless > It does not conduct electricity > It can be purchased in both industrial grades and food-safe grades Sources: www.multitherm.com/multitherm-pg-1.html en.wikipedia.org/wiki/Mineral_oil Ed Schultheis, PE Mechanical design engineer for 35 years My consulting business Schultek Engineering & Technology, Inc. schultek.com

@SimpleTek 2 года назад

interesting

@edschultheis9537 2 года назад

@@SimpleTek I have another thought about heat transfer to the sand thermal battery... Heat transfer between one material and another is maximized by making sure that there is intimate contact between the materials. If this were my project I think that I would experiment a bit with the following setup: 1) Use mineral oil for the working fluid in a closed-loop system, pumping the oil through aluminum or copper tubing from the solar source to the sand battery. 2) Fill the box with sand as you originally planned. 3) Pour additional mineral oil directly into the box of sand so that it fills all the tiny voids between the sand particles. This setup would ensure very intimate contact between the outside of the tubing and the mineral oil in the sand box. This setup would also ensure very intimate contact between the mineral oil in the sand box and the sand particles. This would ensure a very good heat transfer to the sand. I'm not sure how much mineral oil would be required to fill the tiny voids between the sand particles in the box. Hopefully it would not be much. I would do a small test with container of sand of known volume. Then fill the container with water until no more will fit. Then you will know how much additional oil would be required to fill the tiny voids between the sand particles. Ed Schultheis

@jeffreydustin5303 2 года назад

@@edschultheis9537 Mineral oil is a very interesting idea. What about burying a kiln in sand and somehow solar heating the sand to heat the kiln? Inside the kiln is a rockwool blanketed tubing of some heat resistant material that carries mineral oil or salt water to the desired heating endpoint. It is a loop so the cool fluid goes back to the kiln. The sand is a thermal mass and can slowly release heat...buried treasure. The insulation is more about slowly cooking the fluid, because insulation just slows heat transfer, it doesn't prevent it.

@zedostenso3069 2 года назад

@@jeffreydustin5303 A thermos bottle arrangement around the storage would help to slow the heat loss. Now me are talking big bucks.

@stevenjohnson1409 Год назад

@@edschultheis9537 What are the environmental considerations of mineral oil in case of a spill/leak?

@PropensityVisualized 2 года назад

Great series

@SimpleTek 2 года назад

Thank you!

@keevineastridge5107 2 года назад

Small, simple wood stove (or other heat source) powered thermosiphon (55-gallon drum filled with automotive coolant) to radiant heated floor (sand) insulated with aircrete around the sides and bottom. This, combined with insulated back wall - metal on the inside - painted black, filled with sand. If you want, fill a couple of black plastic drums with water to add some humidity as well as adding some thermal mass. I also saw Survival Lilly make a small solar system to power a small heater through the night. I thought that was very creative. You could easily cover the back wall with a white sheet in the summer and remove the black plastic drums as the weather gets warmer during the summer months.

@SimpleTek Год назад

nice

@acmefixer1 2 года назад

What you need to be more concerned about is how you will pump the fluid through the system without melting or burning up the pump, pipes or valves. The way I would do it is to use hundreds of inexpensive flat mirrors to reflect the sunlight through a glass covered hole in the sand box to heat the sand directly. Then circulate water through the sand for use wherever.

@SimpleTek 2 года назад

yep

@NwoDispatcher 2 года назад

How about fiber optic?

@lii1Il 2 года назад

@@NwoDispatcher fiber optics? Is that only used for the visible range? Does it also transfer infrared?

@NwoDispatcher 2 года назад

@@lii1Il well it's all electromagnetism. I'm sure different materials could be used for different wavelengths

@lii1Il 2 года назад

@@NwoDispatcher as long as heat doesn't escape through the fibers as well. Idk, sounds interesting. 52% of heat from solar is IR. Small amount UV. I've studied this in the past on my own including black Body emissivity etc. It's not easy to find a material that is like a diode and heat energy in all it's forms goes through a material without blocking 5-10% even in thin materials. I've seen lights however going through fiber optics straight from the sun to light a space indoors, however they are expensive and probably filter out IR radiation. Curious to see what you come up with? Love your idea of heating a hole in the ground. The glass covering the space and it's emissivity to heat radiation can be a challenge. I've been working on this at home for a long time now. Found one possible solution but the state of the art material is not in production yet.

@TheGijzzz 2 года назад

For a small room/ green house i would say: buy an green egg /ceramic bbq, fill it with sand/ basalt. Stick some 12v ceramic heating elements ptc in it on and connect them the solar pannels. Use the lid to regulate the heat.

@SimpleTek 2 года назад

Expensive but might work

@adytech5788 Год назад

This green egg BBQ has alway burn my steak after 1 min ,i like it blue :)

@richardflowers8073 5 месяцев назад

I learned a lot. Will try some version of this in my greenhouse

@SimpleTek 5 месяцев назад

Awesome

@joemurphy4517 2 года назад

I'm about to build a high performance house. We are using geothermal hvac and solar hot water. We are running our hot water in the roof rain screen with metal roof and radiant barrier. It will be a continuous Ling with no breaks being pumped to an insulated pre tank in the attic. We are in climate zone 3 so our cooling is more of an issue than heating. Non the less we will try it to see how it works out. Good luck with your project 👍

@SimpleTek 2 года назад

I hope your house works awesome! thank you for the kind words!

@michietn5391 2 года назад

Talk about this... to transfer heat from wood stove to sand, try air, thru steel pipe. Wood exhaust contains VOCs so we'll need to use a filter or transfer device to keep our hot air clean. For pumping hot air, use the hot end of auto turbocharger, cold end replaced with electric motor. Other thoughts: supercharge (compressed air) the wood combustion chamber, electrostatic exhaust filter at other end.

@SimpleTek 2 года назад

Great idea

@dfherr86 2 года назад

Used and spent motor oil might be an affordable solution in some areas. Switching to an oil burner isn't the most eco friendly. However that also allows you the opportunity to meet with more mechanics that might be able to help. Hydraulic fluid is pretty useful as it can take a ton of heat and is designed to be pumped. However you heat it, you can contain it in 55 gallon motor oil drums and cycle it through a radiator. Heliostats are great in sunnier places than Manitoba. Honestly an automated pellet stove hooked up to wifi for the auger might be the simplest solution to what you're trying to manage. Just elevate the hopper that feeds the augur and maintain it as necessary.

@SimpleTek 2 года назад

cool ideas

@rodneymoore7270 2 года назад

I would run it thru a good filter first and remember that spent motor oil is also a good base to make diesel fuel

@garyd5622 5 месяцев назад

A 70s solar system used air blowers from a solar collector to an insulated gravel heat storage running year long collecting heat during the summer and releasing it in the winter. Gravel was used to make the air pass through it easier to move throughout.

@SimpleTek 5 месяцев назад

Cool! Thank you for sharing

@shaynearmstrong9290 2 года назад

That's what I start reading comments and lose what I had to put down. I was very interested in the beginning how you were going to store heat throughout the winter. If you have to put heat into the sand you could just as well easily put it into your house (when the sun's available). I'm not sure I would try or waste time storing the heat in the ground unless it was under the house. Maybe build the sand battery in the walls instead. Thanks for some ideas!

@SimpleTek 2 года назад

I appreciate that, look into drake landing solar community

@clydewxi 2 года назад

I would look at conducting tubing both electrically and thermally. It serves as both electrical heating element and air conduit. Bury such a tubing array in the sand. Use the output of the solar panels to power electrical heater. Run an air pump to circulate air through the tubing.

@SimpleTek 2 года назад

good idea

@HawkinsMutes Год назад

This is what I was just coming around to. Another option is to mix some carbon black in with the sand and the medium becomes the heater. Would still need copper pipe to harvest the hot air/water though...

@OktoPutsch 2 года назад

Hey mate, what you need to study are simply "heat exchangers" this is a well known domain and largerly used in the industry, and this is the convergence point between heat storage and its use. The good thing here is that you know which temperature range you'll have to work with, so you can start projecting and dimensioning your installation. Even simpler to design and order well sized thermo-electric generators. Have fun !

@SimpleTek 2 года назад

cool

@inner-mate5089 Год назад

Hi, Would you be able to recommend any sites where I could size efficient 12-24 volt thermo electric generators. Thanks do much.

@angelmadera2263 2 года назад

Hey thanks for info love ur channel

@SimpleTek Год назад

Thank you for the kind words

@reuse_or_die Год назад

If you want really simple and low tech that uses upcycled materials it makes sense to me to build solar walls with old windows or glass doors, especially those from shower units or vehicles, which are very tough and harder to melt down for recycling. I built a rocket mass heater which uses mostly sand to store the heat from my wood burner, reducing the wood used by two thirds

@SimpleTek Год назад

Great idea

@1978jra 2 года назад

Some back of the envelope calculations. 4,19 kJ/(K·kg) *100kg*100K=41 900kJ 0,84 kJ/(kg*K)*100kg*1000K=84 000kJ So yes you can store more heat in sand if you heat it to 1000C but I still would say that water is better choice. 1000C is good forging temperature and I suspect materials that can handle that are quite expensive (at least for small scale). Still sand is far better choice than I anticipated. You might even be able to do it without any piping in the sand itself, just pump air trough the sand.

@SimpleTek 2 года назад

thank you for the insight!

@Sol-En Год назад

I think that the best thermal exchange fluid for sand heating is air at high pressure in pipes. You can circulate this air by high temperature compressor between concentrator and sand heat storage

@SimpleTek Год назад

maybe...

@Sol-En Год назад

@@SimpleTek Turbo high temperature compressor is not difficult to manufacture. You just need long shaft between impeller and electric engine

@katoanthony3704 2 года назад

Great work

@SimpleTek 2 года назад

Thank you

@TheWickerShireProject 2 года назад

We plan on using MINERAL OIL ( it's Inert ) 350F / 180C. Run through Pex using a Solar style water heater/collector with a 1 watt Car water pump. Its simple. System is buried in IBC totes under ground wrapped ( set ) in aircrete. Return closed loop is water ( easy clean up should there be any future failures to the system ) run through hydro radiators. Great Preheater to add to any Hot water system.

@SimpleTek 2 года назад

cool!

@whosonfirst1309 2 года назад

What if you took a new empty 500 gal septic tank and fill it w/ sand/water mix (water added for better thermal transfer) added copper/pex/ stainless steelcoils for both the primary and secondary exchanger and used that? The tank cold be wrapped in insulated board both inside and out. You could manifold the tubing for better transfer also there’s a thing called Glauber salt that phase changes with heat. Just a few thoughts I had, have a good one

@hughmanatee7433 2 года назад

The best system I have seen is much simpler and does use sand. My friend built a concrete building 10x10x10 he used concrete blocks but I would use the styrofoam concrete forms that lock together. Down the middle of the building is a wood stove custom made 2’x2’x9’. The stove is ruggedly built to withstand the weight of the sand. He also used a 16 foot length of 6 inch steel well casing as a chimney welded into the top of the stove. The building has styrofoam placed on the inside of the block walk to keep the heat in and also on the top. The stove is completely covered in sand and a system of pipes are distributed through the sand which goes all the way up to the top of the building. Water is pumped through the sand with ordinary circulator pumps out to his house. He actually rigged the plumbing to his existing oil boiler so he can heat his home with existing piping and radiators. He lights a small fire once every couple of days to maintain the temperature in the heat sink. He has antifreeze in the lines so it won’t freeze if he isn’t using it in the winter. The thing that is better about this system is that there is no creosote buildup because the water doesn’t contact the firebox directly. Also those water jacket heaters only hold so much water and don’t store the heat. My friend also has a domestic water coil going through the heat sink. If he goes away during cold weather he has to blow out the domestic coil because it has no antifreeze. This system can be adapted to use in greenhouses and other uses.

@SimpleTek 2 года назад

very cool thank you for sharing

@patrickcleburneuczjsxpmp9558 2 года назад

@John Pino That's very similar to something I'm interested in doing. Can you recommend ways to get more information/details on what you described, not just that set-up but any sort of related information or links or people...? Thanks!

@hughmanatee7433 2 года назад

@@patrickcleburneuczjsxpmp9558 I don’t have any more info. I know he did buy the plans from an engineer but the plans are outdated. The pipe used was 1/2” pvc and copper. I would think that pex or soft copper coil pipe would be a more modern choice. I know that there was no pipe within 6” of the top of the stove, I would stay away a foot to be safe. I don’t know how hot the sand gets you could melt the pex. I know he doesn’t make a big fire, just enough to maintain the heat sink. If your project requires a lot more heat you could use iron pipe and a larger building. I think my friend’s system can hold a million BTU’s and release 100,000 an hour. I also wonder if a rocket stove would be more efficient. I have also thought about modifying this model to include a charcoal oven so that you could make bio char for the farm.

@patrickcleburneuczjsxpmp9558 2 года назад

@@hughmanatee7433 Thanks very much for the reply. You're saying more of the same things I'm thinking. I'm currently using an outdoor water stove (and the firebox is big enough that I'm also making charcoal in a modified standard size (5 gal?) propane tank), and that system has worked great for me, but the stove is about at the end of its life -- it has a small leak already -- and I'm trying to figure out what I want for a replacement. One thing I'm pretty sure about is that I want to continue to heat with wood and I want to continue with an outdoor system. (I think I prefer a system like I have now that is completely separate from the house, but I might consider a stove that was in/attached to the house if I could feed it from outside.) If the stove itself were all masonry, I wouldn't have to worry about leaks or any water-metal issues with the stove itself, but then if I had some kind of water tank above the masonry I could store BTU's in the tank and use the water to transfer the heat to the house (and maybe use the water to indirectly heat my domestic hot water like I do now.) But if the tank started to leak I could replace it without replacing the whole stove. So that's more or less my idea. I don't know if a rocket type batch firing system (like traditional central/eastern European masonry stoves) is what I'd want or not -- I like that I can currently use very large pieces of wood, that I'm not strictly limited to ideally seasoned wood, and that I can keep a fire going rather than having to start lots of fires, but I realize there's a trade-off in efficiency and how cleanly it burns -- but I guess an all masonry firebox would allow for long-slow or fast-intense burns. I guess a masonry firebox would have to be smaller than what I have now, but I might be able to incorporate a baking oven or warming chamber into the the design. I don't think I've ever even heard of anyone else that has an outdoor masonry stove with water to circulate the heat to the house, but I'm not sure why. Obviously steel water stoves can be mass manufactured and delivered ready to use, but I really like the idea of a more modular set-up that might be able to last a lot longer and be relatively cheap and easy to fix (especially compared to water stoves which rust out or leak for other reasons.) Thanks!

@hughmanatee7433 2 года назад

@@patrickcleburneuczjsxpmp9558 I would avoid any water tank used to save heat. The sand is the key and it is about mass. Go big.

@1mtstewart 2 года назад

Thank you for the challenge and video. I am interested in the concept of developing a "package earth based thermal battery" to incorporate into everything that I build from this point forward. Residence, office, workshop, warehouse, studio or livestock structures should incorporate this into the project while the excavating equipment is on the property, to effectively negate the energy costs of use and ownership for multiple generations and the life of the structures! To be clear (er) the materials cannot be beyond the extended range, for the most part, of the DYI hobbyist, farmer, small business, builder etc... so they need to be obtainable through the normal channels and relatively inexpensive. For subsurface, insulated heat (and cool) storage, i like the idea of corrugated flexible pipes in loops with a manifold at the blower sites to circulate air to charge and reclaim the desired temperature and smooth the peaks and valleys of the temperatures over 24 hours, days or weeks, akin to Earthship design. Since sand is cheap, wouldn't it be better to use to fill around a network of 4"-8" corrugated piping within an insulated sides and top thermal battery below the above structures as opposed to other medias like earth, gravel, stone etc...? Some people may prefer to do this with water or other fluids but beyond the readily available and inexpensive PEX tubing (

@SimpleTek Год назад

keep me informed!!!!

@xXPsych0DadXx Год назад

For delivering right temperature you need simple heat exchanger. Simplest solution, take a coil made of stainless steel pipes and put it in the storage device. Length of the pipes in storage, flow rate of water in pipe and temperature in storage will determine the output temperature. Make multiple circuits with valves that can be on and off ( increasing or decreasing total length of pipe to regulate output temperature). Many electrical heaters for water use this system.

@SimpleTek Год назад

Well said

@kristalmckinstry2095 Год назад

Consider a concentrated reflector system directly heating an air-crete box of sand with one window wall lined on the interior with cupric-oxide. An air gapped box around that box (thus two layers of window) could collect heat losses of the sand box into a lower temp storage like water.

@SimpleTek Год назад

interesting idea!

@donalddalley7274 2 года назад

David Poz has a series of videos regarding his water storage tank and solar water heating panels system. It's just a bit small for his usage, but it gives him up to three days of autonomy. And that is what thermal storage is all about, right? The more days of autonomy the better.

@SimpleTek 2 года назад

I know his channel, great stuff

@PyroEvil Год назад

I did the calculation on my side ( with density and specific heat value of sand ) and I need about 60 000 liters of sand ( 60 cubic meter ) at a temperature of 500 degres celcius to cover my heating needs during winter in Canada. That's enormous ! It's about 10 000kWh of heating energy needed and perfectly isulated. So probably to cover the heat loss , need more than that.

@SimpleTek Год назад

@nickrowe9221 Год назад

schedule 80 steel pipe, used full synthetic motor oil (it is free from your local garage) it will not burn until it gets to 450*F not as high as you could heat sand but it is the most cost effective thing I have found so far, consider using sea shipping containers for your storage, and rockwool insulation (the only insulation that can take 1500*F ) Ive been giving this system a lot of thought for a central heating system for my farm. Resistive heat is horribly inefficient. Im thinking a heat pump would work better... if I charge the sand in the summer the wast cold could be used to cool the house and green houses. Im in NH and we will build deep winter greenhouses that are insulated on all but the south side, so will only need added heat for 3 months. We are still working on design and collecting building materials and will start building summer of 2023. best of luck to everyone trying to figure out this problem!

@SimpleTek Год назад

Sweet

@randycrowe4978 2 года назад

Here are a few thoughts for you. 1. oils and other chemicals are costly and in the case of a spill, may cost a fortune to clean up. If you used oil for pumping the heat into the sand, simplest solution for retrieving the heat is obviously air. Liquid salts are very abrasive and will destroy most piping quickly if I understand that correctly. If you are storing heat, you could even use a Stirling engine to convert some of the heat to electric.

@SimpleTek 2 года назад

interesting!

@umardentras7251 2 года назад

I have such a thought bt don't knw hw practical and efficient it is

@peteraquablue 2 года назад

where can i get a decently sized stirling engine from?

@mariusmossum2923 2 года назад

Assuming one is using sand already; and reaching temperatures well above 100C, then I guess using a steam-engine for generating electricity would be better? Not that I have built one myself. But my research leads me to believe that it will be way more compact, give higher output, will be easier to build, and probably cheaper. Not a steam-turbine though. Would have to be a piston-system, like an old four-stroke engine or something.

@tarawood-bradley2119 2 года назад

As a proof of concept for sand I would personally start with your boiler and building an enclosure around it and filling it with sand. Then the system can grow with solar collectors.

@tarawood-bradley2119 2 года назад

thinking about this, we need to change the boiling point of water, an anti freeze/boil additive. Interesting question is if you saturate water with as much salt as it can hold then how much does that increase boiling point by.

@tarawood-bradley2119 2 года назад

vegetable oils also have a flash point of 406 degrees C. drum.lib.umd.edu/handle/1903/11333

@tarawood-bradley2119 2 года назад

Sand is the storage medium I am trying to think of a way to move that heat from external storage to be usable in the house. An advanced method would be to convert the heat to steam to drive a turbine connected to a generator.

@SimpleTek 2 года назад

great ideas

@BenKoren Год назад

As a thermal mass, the problem with sand is that energy cannot efficiently conduct between granules due to the air gaps between them, so then energy needs to transfer via radiation, which is much slower. This is why sand is known as a great insulator - the pockets of air. If you’re looking for cheap thermal mass, look to “road rock” or “road base”. The specific composition varies by region, but it’s what’s used under roads. It has a healthy composition of large, medium, and small aggregates, and compacts very, very well - meaning that energy will flow through it via conduction, not radiation.

@SimpleTek Год назад

Interesting… thank you

@user-vq4mt4zd4e Год назад

good job and thank you

@SimpleTek Год назад

;)

@z4zuse 3 года назад

The Know You Know channel had an item about Polar Night Energy, 2 weeks ago

@SimpleTek 3 года назад

I saw it - but they don't really talk about how to charge and uncharge the sand battery - just that sand hold heat lol

@matttaimuty5397 2 года назад

I did some research on this very idea. I learned that asphalt will hold more heat, up to a certain point, than any other earthly material.

@SimpleTek 2 года назад

interesting

@jeffstout6567 2 года назад

The denser the material the better the heat holding capability

@michaeljoncour4903 Год назад

stinky

@Omnesum Год назад

Video just popped up again, haven't seen any follow up but a few channels fail to notify. Anyway, consider how much energy your 300C sand actually holds per volume and then look at water in reverse: what is the local groundwater temp and how much water would be required to absorb your heat to below boiling? Depending on how you plan to access/ use the stored heat you could set up a steam turbine generator for electric which could also absorb some energy transfer. You could stall the steam in tanks buried in sand with valves that release the steam/ pressure through other turbines/ tanks until it's just hot water of the desired temperature to heat the house and fill the water heater. This would also distill the water in process.

@Omnesum Год назад

Let me simplify this ramble. If you have a sand tank in the ground, the temperature around it will decrease with distance. Water pipes in the ground where it's around 100C can then be piped through the floor for heating then into the water heater. Same distance diffusion should work with oil or antifreeze

@SimpleTek Год назад

Interesting

@enochaarrestad1168 2 года назад

Using this concept and pv thermal hybrid panels should work great.

@SimpleTek 2 года назад

Yep

@tmbrye2 2 года назад

Have you looked at Russ Finch's methods for growing things in cold climates? If I had a big enough property that is the way I would heat things up like a green house. I'm just starting to look at sand heating and storage for some around the house ideas so I'm just beginning my experimentation. My first challenge is to see how hot I can get sand with just the sun.

@SimpleTek 2 года назад

Yes, he has a much higher ground temperature than I do. I have a video that addresses how to fix that though

@nigelwilliams7920 3 года назад

Well a cubic metre of sand stores 105 MJ for a heat difference of 30C, while a cubic metre of water stores 125 MJ. So water is better up to 100 C. The advantage of sand/rock is that a much higher temperature differential is available. But, as you say, and as my own contemplations have found, the complexity of dealing with temperatures over 100C on a domestic set up are too much. I can buy at 30 cubic metre plastic or concrete water tank for about $3000, and if that is heated to say 60 degrees above ambient, then I have 7560 MJ of energy stored there. Foam concrete insulation, plus fibre glass batts would slow heat loss enough and such a system would be affordable and simple enough to build. Hot rock/sand with say high pressure air to transport heat from the solar concentrator is just toooooo hard for the ordinary person. A bit of warm water plumbing and a few circulator pumps is a simple job.. 7560 MJ is equivalent to 70 days heating at 30 kWh per day. Even assuming 50% lost via heat losses, and another 50% lost via poor transfer effeciencies, that is 35 days at 15 kWh per day. If your heat capture panels are able toget anything like 30 kWh input on a normal winter day, then you are safe for the full year's space heating providing you don't get more than 15 days rubbish weather in a row. You would see the storm coming anyway, and button up tight to conserve the resource. That sounds viable to me. Rocks or sand? Too hot to handle, IMHO..

@SimpleTek 3 года назад

interesting! thank you for the reply

@myounges 3 года назад

I fully agree on domestic DIY scale you need to get as simple as possible because even the easiest setups bring unexpected challenges... :) Check out a guy called Sergiy Yurko he has a channel about a lot of solar collectors and thermal storage. Really interesting.

@SimpleTek 3 года назад

@@myounges I actually have a channel link exchange with Sergiy. He does INCREDIBLE work with solar collectors and water thermal batteries! I absolutly LOVE his work.

@myounges 3 года назад

@@SimpleTek great minds think alike... Haha yes that guy really takes his job seriously. 👍

@graveseeker 2 года назад

How about lights, cooking or cooling for those of us in the deep South? Shouldn't the system provide electricity?

@randallshuck2976 2 года назад

They have been doing this in England for years. The average house in the UK in the 1970s had a gas or coal fired furnace that ran long hours every day. the flue of the furnace was surrounded by copper pipes that absorb waste heat as it is going up the flue and heats water/oil which is pumped to each room and through a block heater that is roughly 4 ft long 3 ft high and 3 ft thick. the block heater is filled with the copper tubes surrounded by and sand it absorbs the heat all day and radiates it out all night when the furnace is banked down to conserve fuel. It stays warm enough to keep the average size room (10 X 10) toasty. It serves the same purpose as the hot oil or steam radiators that were standard until the mid-sixties in the USA with the added benefit of holding the heat longer. It isn't so much a factor of how extremely hot the water/oil gets as much as how long the heat is allowed to build up before the heat source is removed.

@SimpleTek 2 года назад

That’s awesome

@DigitalAwareness Год назад

great ideas

@SimpleTek Год назад

Thank you

@metatechnologist 2 года назад

Regular store bought PVC pipe can go to 140 F or 60 C. While it won't be the primary "coil" it certainly might work in a return/transfer circuit.

@SimpleTek 2 года назад

need more heat!!!!

@ronson-natsarim Год назад

The flow rate of the liquid through the sand determines contact time which regulates thermal energy absorbed by the liquid. You could run water through 1,000° sand and adjust your flow rate so that the output temperature is 70° (or whatever you desire).

@SimpleTek Год назад

nice

@kyleburdick8771 Год назад

Water run through 1000 degree sand would be steam...

@SimpleTek Год назад

@@kyleburdick8771 depends on speed, length of run and contact time

@kenhilving276 Год назад

How do you get around having some water left in the pipe where the sand continues to heat it to super steam?

@SimpleTek Год назад

@@kenhilving276 good point

@harmonysalem9377 2 года назад

Merci from Montreal, Canada.

@SimpleTek 2 года назад

cheers from Oak Point, Manitoba!

@NeilStansbury 2 года назад

I've just finished lining the interior wall of my house with 20mm corrugated cardboard filled with very fine sand to act as acoustic barriers and a thermal heat sink, we'll see how well it works later this year. My suggestion would be to buy 9 cheap copper electric immersion heaters. Remove the immersion units and fill each one with your copper piping and sand. Then sink each one of those units into a concrete "jacket" in a 1, 2, 3, 2, 1 layout and surround that jacket with the water. Concrete has excellent thermal mass itself, is easy to insulate all around, has high heat tolerance, and it's water tight. With individual "heating units" units you can easily replace/upgrade when needed.

@SimpleTek 2 года назад

I like it!

@NeilStansbury 2 года назад

@@SimpleTek Btw, the reason I suggested a 3x3 layout of the immersion units rather than in a circle was the XPS insulation that is designed for below grade insulation comes in large 2.4x1.2m sheets (in the UK anyway), so insulating a square concrete jacket rather than a round one would be much easier. I also suspect running the water through a square jacket would be simpler too.

@danlds17 Год назад

You're worried about 300 F deg air being too hot for your house. So at a convenient point after you've extracted the heated air from your sand-mass, mix it with a variable amount of external air to achieve a reasonable temp. for your home. The engineering for the mixing area might be expensive (in order to not lose your original stored energy), but I'm not an expert. Or another idea, just pump the 300 F deg right into an old-fashioned floor radiator (the kind originally built for steam).

@SimpleTek Год назад

Well said

@kickeryou 3 года назад

For charging use electric Resistive Heating and solar. Vehicle Glow plugs can heat to 1400C. Stove elements can heat to 900C. For extracting heat look at copper pipe and air to a holding water tank like you discussed. I wonder what a regular hot water tank filled with sand would do if the aquastats are modified for high heat?

@SimpleTek 3 года назад

Thank you! very interesting ideas!!!!!!!!

@jeebus6263 2 года назад

More volume would be more efficient, a well insulated water tank may be a good test bed tho.

@ai4px 2 года назад

Glow plugs and resistive elements get heat in. How to get it out?

@Swampwild1 2 года назад

Great video. I’m in Hadashville. Here’s my main point- if I buy a system that can meet my needs in the winter then I’m producing 10-15x the power I need in spring/summer. So efficiency is irrelevant, it’s all about cheap storage and retrieval. Especially with panels price dropping. The panels are probably 1/4 of the total system cost.

@Swampwild1 2 года назад

I like the idea of sand heated with glow plugs. Simple reliable. Imagine using TEG to convert that heat back to electricity. I know it’s very very inefficient. But someone do the math for me. How much sand? You could create a 2 stage sand cell for just the hydronic heat. But you probably also need electricity because we get so little in December? I use wood in a soapstone fireplace now, hope to do the Chinese greenhouse maybe.

@k1ng401 Год назад

I imagine a large insulated storage container with two sets of copper tubing coiled inside surrounded by sand. One set of tubing circulates heated air from a standard electric heater through the sand and heats it, the other tube also full of air which is heated from the sand is ducted to a fan in your house or greenhouse. The sand heater operates during the day, usually powered by excess solar. The fan that circulates the heated air inside the house can run at any time but in daytime will usually be solar as well. I’m just not sure if the air will be too hot straight out of the sand battery and the best way to manage that. If it is is too hot then I’d siphon off some of the super hot air, mix it with outside air to cool it to the right temp before releasing it in the house.

@SimpleTek Год назад

Cool idea

@peterrogers3085 Год назад

Use air collectors to heat the mass and then a separate air pipe to pump back out the heat, you can then introduce the hot air via a mixer pipe of local air or feed it into a large mass radiator in your home. Pump the air from the cold side into the heat store and receive the heated air.

@SimpleTek Год назад

Good idea!

@robertclark8928 2 года назад

You could use photovoltaics to run an electric heater to heat air and blow it through tubes in a sand battery. The same hot air would be recycled around in a closed loop and continuously reheated by the electric elements of a heater. I don't know how hot you could get it but I would think you could get it to at least 500 degrees like an oven.

@SimpleTek 2 года назад

I like it

@mattstaat2646 2 года назад

This is what I am investigating. Right now I'm uncertain on how to calculate the area of heat an individual pipe would transfer into the sand.

@edclark6543 Год назад

Couldn't you just use heating elements embedded in the sand?

@andrewb9595 2 года назад

Love the idea of using aircrete (which I was thinking of doing myself) for the insulation on your storage tank. You could build the tank entirely out of aircrete and rebar OR you could buy a metal water tank (like a livestock tank) and insulate it by filling aircrete around it. Storing heat that will be used for heating is easy enough, but storing heat and transferring it into electricity to cover the other 40% of your homes electricity demands when the sun isn't out is the real challenge.

@SimpleTek 2 года назад

great ideas!

@lii1Il 2 года назад

Andrew, love the idea of storing water in livestock tank and insulating with aircrete. May need to waterproof aircrete as water may seep through it and exposed parts may crack with ice allowing water and thus corrosion as long term issues. Great idea however. Water even at lower temps under 200c is still great at storing heat just requires more space to meet total needs. Yes storing heat does not account for the rest of electric bill but it's a great start and reduces the rest. If one uses high temp solution, the stored heat can be used for cooking! That's cool! May be more practical to have a dedicated system for cooking to reduce cost such as piping, building etc. and for simplicity. May be easier to have solar panels and batteries for the remaining electrical needs. That's my guess. Turbines for electricity are cost prohibitive to my knowledge.

@andrewb9595 2 года назад

@@lii1Il Batteries are also pretty cost prohibitive if you have grid access. As for cooking and/or energy generation when the sun isn't out, a methane digester (piped directly to the stove or to a generator) wouldn't be a terrible idea. Also instead of solar panels, I've been looking into the idea of using a parabolic trough collector to generate electricity via a sterling engine and then collect the water after the sterling engine as stored hot water which can be recycled in a closed loop. This would be one hell of a project, but it'd be totally off grid depending on your energy demand and geographic location.

@lii1Il 2 года назад

@@andrewb9595 keep me in the loop! Want to see what you come up with. Biogas is a thing. It's common in India I have been told and perfectly clean. Big or cow poop may work better than human.

@ericslayton4779 2 года назад

@@lii1Il hydrogen sulfide is not clean but can be filtered out with activated charcoal and lime water.

@autismfarmer1504 2 года назад

Simple Tek, If you move to New Brunswick let me know. Here is a Catastrophe-Prepper type perspective: Water storage is critical. Having electricity is critical. Having compost is critical. Here are my suggestions based on a pole shift scenario where the sun is blacked out and the earth is wobbling for 12+ years. Water barrels can hold up tables in greenhouse. Wind power for grow lights and water pumps. COMPOST THERMAL BATTERY for heat & natural gas creation 120F to 170F. Pallet wrap used for quick repairs to greenhouse film. In prepping there must be many redundancies such at: Fans that pump upper air into the lower sand thermal mass to regulate the heat in the greenhouse. Here is weak point in this plan: Massive earthquake, wind & hail falling from sky and fire. The redundancy for this would be creating an ICF underground greenhouse bunker. Keep 8 mil silage tarps, solar panels, etc. stored until after event has subsided to install at a later date.

@SimpleTek 2 года назад

will do

@rolandroka2082 6 месяцев назад

Sand battery is probably one of the most interesting idea to store heat energy for a long time. I am thinking about to realize that in a small scale, just for an alternative heating source for my house. Interesting question is, how to transfer heat out of the battery (in my case, intake goes trough electric heating element attached to a solar system)? Well, i think the cheapest version is the air (free available, heat resistant) . Also, you can use it in some kind of heat exchanger to heat up oil, watter or even another separated airflow like room heating with air.

@SimpleTek 6 месяцев назад

It is a great idea

@dustind3502 2 года назад

Air under the sand should rise through the sand while heating so long as it remains dry and you have coarse sand. Delivery of the air could be as simple as metal piping to molded holes in the air create.

@SimpleTek 2 года назад

interesting

@lii1Il 2 года назад

I would be afraid of air quality issues with the air flowing through the sand. Yes it would rise and heat but still. Cheaper than piping. If the air could heat separate air or surface UNDER an air barrier then perhaps.

@dustind3502 2 года назад

@@lii1Il if air quality was a problem, a simple heat exchanger would nullify the problem. Dirty air on one side, house clean air on the other. Or wash the sand and use an air filter until the fine particles are gone.

@lii1Il 2 года назад

@@dustind3502 yes heat exchanger would be ideal for this build. Also as few engineers seem to know, water vapor also rises slowly through the whole building, and wood framing would not respond well but mold and other nastys would love it! Therefore you would have to install a robust dehumidifier. So as you stated, it would need a robust vapor barrier and heat exchanger which are sold commonly on the market. TY

@zedostenso3069 2 года назад

@@lii1Il Takes a lot of energy to operate a dehumidifier.

@anomikak1062 2 года назад

Have you thought about moving the sand? My knee jerk reaction is to say it would cost too much to move the sand except in a separate battery project moving sand is the actual solution to a physical electric battery. I wonder if you could combine those 2 systems. The sand is slowly moved upwards by (excess) solar panel power via a standard motor. But move it upward on a parabolic mirror trough. As it goes up it is storing both potential energy and heat. Once it's hot, drop it off the trough and into your aircrete tank which is 20 feet off the ground or on a hill or cliff if available. When your batteries need charging or you are cold you drop the hot sand down a pipe and collect the electric via inverter and the hot sand lands inside your green house where you blow a fan it to extract the heat into the air. The sand sits in some sort of "sand radiator" until it's cold and you use a microcontroller to open the flap at the bottom and the sand drops out into the base holding tank where it waits for a sunny day to make it's trip back up the mirror trough. I like this idea so much I'm going to try it. Thanks for the inspiration.

@SimpleTek 2 года назад

interesting

@tedrookstool6627 2 года назад

MOVE THE HEAT NOT THE SAND.

@gregjohnson9051 2 года назад

Look at an infrared heating system that would be found in some commercial garages. They have a 4” black steel tube with reflectors. You might be able to use it in reverse.

@SimpleTek 2 года назад

interesting

@rodneymoore7270 2 года назад

In looking into this it appears to be advantageous to put rock on the top of the sand before the aircrete enclosure. In that enclosure heat of course tends to rise and the rocks can store additional heat before the aircrete insulation comes into play .....

@SimpleTek Год назад

interesting

@tonyarnez5193 3 года назад

Check out Korean traditional floor heating system ... basically a giant rocket stove under the ground that could heat the sand which will radiat a constant temperature all night !

@SimpleTek 3 года назад

very interesting!!!!! Thank you

@michaelglenning5107 3 года назад

Sounds like the Russian system as well.

@SimpleTek 3 года назад

@@michaelglenning5107 which Russian system?

@michaelglenning5107 3 года назад

@@SimpleTek Russians would build a slightly off horizontal chimney in the ground. The fire box would be below ground. Seasonal solar heat storage is the same concept. Heat from the summertime is pumped through a horizontal underground air duct system. In winter the heat works it's way up. I see numerous people venting excess heat buildup in the greenhouse outdoors when in fact it should be transfered to the ground underneath it.

@michaelglenning5107 3 года назад

ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-7PXfvfZ-b-o.html

@garywillis5790 2 года назад

The higher the temperature the higher the losses. The best way to my mind would be to pump the heat into the ground in the summer, then extract in the winter. The heat wouldn't heat your home for long without the aid of a heat pump, that's the only issue! Greenhouse would perhaps keep it ice free year round.. although the losses from a greenhouse are massive.

@SimpleTek 2 года назад

good insight

@beaurobinson4518 Год назад

@@SimpleTek hho

@beaurobinson4518 Год назад

@@SimpleTekhydrogen on demand It burns at very high temps and is easy to generate using solar And you do not have to store hydrogen

@philipbrown1433 3 года назад

Use durasol or faswall ICF for your storage walls walls filled with aircrete. Fireproof insulated structure for your system.

@SimpleTek 3 года назад

interesting.... thank you

@roberthicks5454 2 года назад

As for the storage container, what about layers. The inner layer, say 10 feet diameter, is surrounded by something like Styrofoam, which is also surrounded by more sand. The Styrofoam insulates the heat form the next ring and the sand slows the transfer. I was also wondering about having wet sand and the styrofoam would block the water from aiding in the transmission from one ring to the next. I would think you could have several ring to keep the heat from escaping. I have heard that hydrogen or maybe helium is a good transfer medium as long as it is completely sealed, but I have no idea of the cost.

@SemperBlood 2 года назад

Going in blind. I would go with Iron piping in a sand pit. Just use air to charge it in the summer. And air to siphon out the heat. The higher the temperature the less air you need to move throughout the system.

@SimpleTek 2 года назад

interesting idea

@kimmer6 2 года назад

Air is not that good of a heat transfer medium. Hydrogen conducts heat 7 times faster than air. That's the lifeblood of every refinery and its in almost every generator over 100 megawatts but it finds every crack and escapes. Liquids are a better heat exchange medium especially if a phase change occurs...gas to liquid, solid melting, etc. Water is the cheapest most available heat transfer medium. I was going to try filling a 275 gallon IBC tote with road base gravel with 6 inches of sprayed rigid urethane foam as an insulator and water as the transfer medium. Ain't got there yet....

@redstone1999 2 года назад

@@kimmer6 I thought the same thing. But the plastic of ibc tote needs to be below 160* F (preferably 140* F or less). My plan was using it to regulate water temperature of fish tank at 80*F year round in my insulated fish-house. The plan is down-sized to a 55 gal steel drum with PEX and sand-gravel mix as water heat exchange/bank. The ibc is better used as another 25 kgs of fish raising and water volume is a heat bank also. The floor is 6 " of sand & river gravel and polypipe over 4 " of insulation board (R-20) base. ( I wanted to go 2-3 feet deep and do STHC system. But time frame & finances did not allow it. )

@kimmer6 2 года назад

@@redstone1999 I was planning on having a roof company spray 6'' of rigid urethane foam on all sides and top and bottom embedding the steel frame. Then it wouldn't really matter how hot the IBC tank got as it is encapsulated. Make a top hatch to load it with sand/gravel. I had 2 inches of foam sprayed on my roof 18 months ago and the stuff is wonderful. I can walk all over it and not damage anything. My attic fan rarely comes on at all any more. The foam insulates really well. We had 106 degrees F the other day and the house bottled up got to 79F. The attic was 88F. I saw 119 degrees F in the attic with the laser thermometer 2 years ago, and 106 degrees on my bedroom ceiling. Roofing foam is way more rigid than foam in the can. You have a good plan. My aquarium hobby went down the tubes decades ago. My son was 3 years old and turned the thermostat to full. I came home and $1000 worth of tropical fish were dead.

@redstone1999 2 года назад

@@kimmer6 Kids ??? Lovable little lords of destruction :D I like the idea of insulating my fish tanks with roofing foam.

@michaelkaer 2 года назад

If you build the collector on a big home made lazy Susan, alignment would be easy. I would try mineral oil if you can get it.olive oil can go rancid.

@SimpleTek 2 года назад

interesting idea.

@68HC060 2 года назад

@@SimpleTek I think this is an excellent idea, especially if Michael is saying that the collector is the full size of the lazy Susan, rotating slowly and having only a tiny bit of it exposed to the heat source. If it rotates into an insulated area, this would probably be the simplest and perhaps most cost effective way of making a heat collector + storage. No need for pumping.

@68HC060 2 года назад

-And you could of course use sand for storage, but you really could use _anything_ - including big flat rocks. ;)

@68HC060 2 года назад

And the first time I read Michael's comment, I understood it as it was meant to be understood. -The 'storage' idea came from when I skimmed the comment a second time and completely forgot that the lazy Susan was about alignment and not storage. =)

@sarahhavillamelooliveira5825 18 дней назад

I was thinking in the lines of no-movable parts, sun thermoelectric energy. It would be probably less expensive and safer. My idea goes like this: two tanks. The top one is circulating water due to it's high specific heat (my location does not freeze) that goes into an caco3 paint based heat radiator. Colder water sinks, therefore the coldest part would be in contact with the peltier. Lower one is filled with sand and has a pipe circulating oil (in a pinch sunflower or soybean oil migh work) and into a solar contrator. Again we assemble it in a way that the oil will cicle on its own based on the fact that heat goes up and cold goes down. I have no idea of how well this would work, but I tried reducing failure points while increasing heat difference, plus diminishing costs (less of those expensive metal tubes). The good thing about this system is that it will still produce electricity at night. I would use this only for electricity generation thought. For heating water for daily use I would use the water-sand methods.

@SimpleTek 17 дней назад

Interesting

@riverhouseparadiseproject3298 Год назад

I've seen videos of simple electric ceramic heating nodes. They seemed to get to incredible heat over time with little electricity. If i recall they could be placed under a copper sheet to transfer a larger area of heat up into the sand. From there I don't know if simple air tubing or liquid tubing would be better. I would think air that could then be moved to a 2nd area for conversion as you mentioned.

@SimpleTek Год назад

Well said

@CS-uc2oh 6 месяцев назад

12v ptc heaters they are called

@ttaylor7777 2 года назад

The Cp of Sand is about 0.8 KJ/(kg*K). So if you heat it from 0 to 500C you get about 400 KJ/Kg. Water taken from 0 to 100C will give you 418 KJ/kg. About equal to sand with only 1/5th of the temperature change. If you can use steam the value goes up to 2776 kJ/kg. Most good storage media use phase change to provide much great energy density in a small range. If you want to use something for heating or cooling you are better off using palm or coconut oil with a phase change temperature near what you want to use for room temperature. Sand will require too much mass, space, and infrastructure to be worthwhile.

@SimpleTek 2 года назад

wow

@matthewnewton9129 Год назад

But you aren’t generally going to be heating water from 0-100. More likely from ambient temperatures to about 80c to avoid pressure problems. So a lot less energy storage. Also you will have steam/evaporation problems with water or degradation problems over time using oil.

@mbseeking6570 Год назад

Which is not a lot of heat. 1kWh = 3600 kJ...

@EpicTurbulance Год назад

A hero once said "I don't like sand", then burnt to a crisp.

@SimpleTek Год назад

@MushInSkull 6 месяцев назад

Sounds like something Anakin said. 🤔😁

@twosongs7396 Год назад

You’re brilliant!

@SimpleTek Год назад

Thank you for the overly kind words

@wildfun496 2 года назад

Make a manifold out of concrete or any metal or high temp pipe, bury it in an insulated sand box with pipes, and run hot air through it, and at night it should hold heat, also you could just put the whole thing under the house, just use separate pipes that lay on top of the block and go back into the house for heat at night, the out side could have a temp thermostat ,on, off fan could be solar with small battery back up. Also you have radiators, you cold bury a tank or manifold in the sand box, circulate the water through everything, have a high pressure safety valve outside and in. The sand should take a lot of the heat out, just have a shut off for high heat that way the temp won't go too high, or loop the water that is in the radiators somehow, till the temp drops, separate from the solar setup, Just ideas that may or may not work! but good video, and I also subscribed!

@SimpleTek 2 года назад

Good idea

@Bucksighter 2 года назад

What has a better thermal coefficient for a heat battery medium, clay or sand?

@SimpleTek 2 года назад

I don't know!

@rainewalker532 2 года назад

The problem with clay is that any moisture contained in the clay at the high temperatures would turn to steam which would cause pockets to form in the clay or worse could cause a steam explosion as it heated up in a tight space.

@lmeredeemed5043 2 года назад

I just watched the Finland group who are the inventors of using sand. This site may have gotten his idea from The Polar Night Company in Finland.

@SimpleTek 2 года назад

both very interesting concepts!

@tmbrye2 2 года назад

I wouldn't say they are the "inventors" of using sand but hopefully they can make it to a reality. Thoughts of using sand have been around more than a decade ago.

@jimargeropoulos8309 2 года назад

I was just re reading Bob Ramlow's book solar water heading. He warned that oils as heading loop fluids cause issues with any rubber seals that they encounter. Also that ethylene glycol is toxic and should be avoided as a transfer fluid. He also talked about insulation, saying that common ones will melt or degrade in uv.

@SimpleTek 2 года назад

interesting - thank you

@lii1Il 2 года назад

Ceramic Fiber gaskets are good up to 1000c but can be brittle. I'm sure with a little research one can find higher temp ones. PTFE up to I think 260c but I typically would keep operating temps 10% lower than ratings jic.