Sand Battery heater. Create free heat over 514F using solar electricity!
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Your questions answered here:
• Sand Battery QnA.. Fre...
• Sand Batteries Effecti...
I generated over 500 degrees of heat using 50 pounds of sand and 240 watts
0:00 intro
00:35 What is a sand battery?
2:26 Small scale example
3:44 Large scale
4:58 A discovery
7:53 The lid
12:39 Finished. testing begins
15:41 Recap
Don't forget to check out my other videos for more projects!
Reference links below.
• 1752 A DIY Sand Batter...
• 1752 A DIY Sand Battery - The Theory,...
@ThinkingandTinkering
@desertsun02
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Thirty years ago, my uncles and dad built a house for my grandparents in Fargo ND. They used electricity to heat the house. In Fargo, footings have to be deep and most people have basements. In this case they lined the concrete with insulation and filled it with sand. They ran heating tape through the sand. The local power company had a special off-peak rate. The house was well-insulated and could go for several days in the middle of winter without power.
I don't remember how they controlled the sand temperature but it wasn't that hot since the house was always 75 degrees F and there was no control between the sand and the concrete floor.
I was actually born in ND and got family in Fargo!. It was probably just a big thermal mass but I'll have to ask the relatives still in the area if they know more.
My hat is off to your family, Texas Prepper and all the amazing people that live in ND. I worked up there for many years and I am amazed how resilient and friendly people up there are. When someone talks about people being the backbone of the our country it these kind of people.
Woulda been nice to see it instead of hearing about it. Great thing about videos
@@ourpeoplespoll1474 What would you like to see?
If you could explain the original comment @texan prepper, about using this type of thermal mass to heat a basement as original commenter described that would be amazing.
I kept getting up to let my cat in, but she wasn’t there 🤷🏼♀️. Then I realized it was your cat crying 😂.
Prepper cat George!
I'm about 8 minutes in and I thought I'd point out a potential electrocution hazard.⚡The contacts for the wires on the heating element are not meant to be surrounded by any material. The loose sand and/or the fused sand connects them together providing a path for a short circuit.☠ A solution might be some high-temperature silicone gasket material over each terminal separately. Also of concern is the plastic on the wires, it might also melt in this application. So additional insulation around the wires, with suitable high-temperature material, would be a good idea. Or a better idea as "daughy doc" suggests, make a hole in the side of the container and insert the heating element the same as it would be in it's normal application in a water heater.
I was also concerned about that and I do think it is a valid fear. I have multiple fuses in this system in case something like that happened. Thanks for the comment!
Dry sand is non conductive. There should be no electrical problem. Unfortunately sand is also not a very good heat conductor. A water heating element will burn out very fast as it is designed to have water around it. Water is a much better heat conductor. I think a solution would be to have something havey in the centre that is a good heat conductor and then use the sand arund that as an insulator. Water heating elements are only designed to handle heat up to a little over 100 degree Celsius.
@@leonhardtkristensen4093 That may be the case, if it's clean and 'only' sand, but I still wouldn't touch it while the heating element is turned on.
@@Mavrik9000 That is allright. Safety first of cause. If it is used with low voltage like 12 or 24 volt it is no problem and if it is used with 240 volt I am quite sure the heating element would burn out in no time. With mains voltages one should allways be very carefull. I have had my fair share of electric shocks and survived but it is true that if not used to it even a smaller shock can give a deadly amout of andrinalin in ones body. It is often not the electricity that kills but the adrinalin that does it.
You could also drill a hole in the can and stick the element and the wires out, just be sure all connections are protected with electrical tape.
awesome job mate
Hey bud! Looks like we frequent the same channels. You should do another?
My thoughts exactly , thanks to both of you
@@dennisking8892 Hey Dennis. Have you build one of those HHO generators such as the one on your site with Patrick Kelly? Good instructions btw. If it works, I would be interested.
@@lii1Il no I haven't made it, good luck . I did also see American cop cars taking advantage of the Tec ,on another TH-cam video
@@dennisking8892 interesting! Do you have that vid?. Does it have reliable directions? It's a lot of work so if I'm going to invest that much time and energy, I need to know it is going to work. Biggest concern is hydrogen embrittlement. It very well may greatly reduce the life of the motor which is not worth it unless it's made of 316l stainless which they never are.
I love how you had multiple points of temp measure. Good job and simple yet reliable design. My 2 cents, add a larger heater with more surface area like a range heater or one that comes with wiring designed for really high temps. I would also do like you suggested, drop a pipe into the sand that could be supplied with an air source to be turned on when you want more heat. Please more videos
check out my other videos for more and better testing
This is a pretty cool idea I'd like to mess around with myself. The comment section is GOLDEN!
I've used popcorn tins filled with sand, pea gravel and/or bricks with an incandescent lightbulb to set under metal chicken waterers to keep them from freezing. This is somewhat along those lines.
Vaseline or cooking spray oil work fairly well as release agents for plaster.
I thought about the popcorn tin since we just got done with Christmas! I've seen several variants of this design including one using tea candles sitting on bricks. Sand is cheap, it's interesting and easy to play with. I'm just so STUNNED at the 500f I got out of it
I am wondering how to create a safe place to put something that 🔥 hot.
Downstairs is always cold. The heater isn't that efficient if temp drop too far and it doesn't circulate. Downstairs is lightly refrigerated, upstairs is warm.
I can see setting up one or two of these to radiate heat Downstairs...
but 4 cats 🐈 🐈 🐈 🐈 ...
I have worked on off peek heating systems for a utility company. I think what you have done was a good experiment. 60 volts at 4 amps is 240 watts 5 hours of sun light that's 1200 watt hrs. i have a space heat that i use in my camper just to keep the bed room warm at night it uses 800 watts on low your heater would be = to running my heater 1.5 hours. not to bad. there are homes that use river rock to heat there home in Canada and with no sun for 30 days it kept the home above freezing. tons of river rock one pound of mass takes 1 btu to change it 1 degree.
Thanks!
This is better than school
Thanks for sharing your experiment. I saw another channel trying a similar method. The water heater element just got destroyed from the heat (he could easily break it apart in his hand after it cooled down). He ended up using the element from a stove instead.
Can you link to it? Mine seems to be falling apart also but I'd love to see others!
@@texasprepperprojects here is a link
www.youtube.com/@off-gridsurvivalmike8120/videos
What is the link? Looks like it was removed???
@@NORSKGARDEN it was on this channel. Update 5 or so. It was one of his earlier vids before he switched to stove coils www.youtube.com/@off-gridsurvivalmike8120/videos
There's already oil filled thermostatic heating devices in the market place so why not run the solar wiring power supply to energize such a device or bury one of these in a box of SAND ????? 😮 😮 😊 😊 ❤ ......
I just watched another video where they used heat powered fans on top of the sand to spread the heat (the kind you use on wood stoves).
I have seen that same video. It's given me an idea for something similar. Stay tuned
@@texasprepperprojects if you are interested in that scenario, please consider the idea of using Stirling engines to generate electricity. Say enough to charge a "Power Wall" and to provide juice for the heating element. Also look at the linings for small scale smelting operations and fire brick. I would be very interested how it turns out since I live in a rural area of the Hill Country.
I played with the sand idea years ago but wanted some features that would be difficult with sand so I changed to mineral oil. It can still get up to 500 degrees and yet is easily moved to where it is needed via plumbing. To save on cost I filtered used motor oil several times to clean out all the fine sludge that could clog up the pipes. It gets heated by being pumped through a set of solar evacuated tubes, with the pump being controlled by a low voltage thermostat so it only runs when the tubes are hot. It goes into a highly insulated tank for storage (the battery). The size of the battery determines how long it will work for those cloudy weeks when there is no charge available. As needed it gets pumped into each room where it passes through a small radiator which has a small fan blowing through it. Hot air comes out the front. Each room has an independent pump and thermostat. I'm working on an in-floor radiant system as the next upgrade that will be built into my retirement home. Because it is thermostatically controlled, I can leave for extended periods and not have to worry about my pipes freezing. I love not having a heating bill yet still being quite comfortable regardless of the weather. Another upgrade will be a heat exchanger used for domestic hot water. That will have to be regulated more precisely to avoid scalding.
Best idea I've heard yet
Neat!
catch 22....... FIRE.. no this system should not catch fire from anything about the heater ...BUT.... if your home catches on fire some other way..... its mostly a gonner once that oil catches fire (or its fumes) ...... that oil fire will be nasty..... Also if any unburned oil leaks out- odds are you may get a big fine and/or required to pay out the ass for environmental clean up and have EPA all over your ass.
be aware as well....... this setup completely invalidates your home insurance. They will not cover "Anything" including things unrelated to this system. Ins. Company Lawyers are paid to find excuses to not pay back out to who has been paying in. They likely will use this heater as an excuse.
Not saying folk should not do this.. just be prepared (put $$ you would pay for insurance into high yield savings for example- aka "self insure"). Be honest and straight with firefighters if you have a fire.... they need to know about the system IMMEDIATELY... be aware too the captain may call all his fighters off the job and only do water cannon from distance... for the safety of firefighters
The use of oil sounds interesting. The circulating water radiant floor is becoming more common so it should be easy to incorporate this idea. I’m a little apprehensive about sleeping on top of a pool of hot flammable liquid but with the oil battery surrounding an antifreeze/water heat exchanger ,that more energy-dense storage sounds good.
@@danielking2944 use type oil found in electric oil heaters and/or powerline tranformers?
Nice video , thanks for sharing this with us. I think I may be able to use this for sure.
Thanks!
:) this sounds like fun going to add to my bucket list of projects.... thanks for followup video - I recommend to watch it as well
Sounds great!
We are in Connecticut and really like this idea. My husband & I live in an electrically heated apartment building, so a quiet, non-fume producing solar heater sounds great! We have read through alot of the comments to find suggestions for improvements. Here is our plan: We will be using an old steel milk crate to keep our heater up off the floor, an electric stove element along with the ceramic socket and high temp wires from the stove, (or a hot plate if we can find one) and basalt (igneous) rocks surrounded by sand for a denser thermal mass. We will probably use furnace (refractory) cement to create the top cover and ceramic base for the heating unit, which would allow us easy access to all parts if needed. We already have a few 12 vdc fans salvaged from old computer towers to circulate the air.
Watch all my other videos on this. Short answer, don't bother. An electric blanket will keep you more warm and doesn't use much power
Um…in CT there is NO NEED to save the heat until night time!! Just have the panels run a DC heater WHENEVER it’s sunny!!
Tell your insurance company
thanks for bring up the computer towers. i have a mining rig, that's new. i wonder if it would work the same?
@@texasprepperprojects i'm sure those can be ran off my eco flow over night.
Thanks for your work. Im working on a similar concept, mine is targeting the size of a fridge, with outer walls design with high temp insulation. Internally I will do a copper coil for heat extration via pumped water, and multiple 220v heating coils. Will do design so sand can be emptied, and filled. Put it on a pad outdoors, as its going to be heavy. My offgrid solar is 24 Kilowatts of power, so this will be my dump load, when my batteries are full, I can redirect during the day to the heat. my house is already designed for radiant heat, so easy to use hot water for it, or pre-heat for house hold hot water and hot tub.
Use a radiator fluid it will raise the boiling point of the water.
Cool
Neat
Excellent video, and some of the comments are very creative and useful, too.
Thank you.
Glad you think so!
Great video! I'm fascinated with the idea of storing solar heat gain directly. It seems like a reasonable and worthwhile endeavor.
Any dense material can hold heat. All materials have their own unique physical characteristics. Dry sand is a great idea because anyone who's walked barefoot on a sandy area knows how hot it can get. Water is another dense material that will hold it's heat, although it tends to give up it's thermal energy quickly. Water is nice because it flows through pipes and can carry the heat from one place to another.
I once read watched a video about storing heat in paraffin oil. It's most outstanding physical characteristic I can recall is that it doesn't boil until 500 - 600 degrees fahrenheit! And it flows through pipes and hoses.
I read one comment from someone who would set a 5 gallon bucket of paraffin oil on his wood stove in the evening as the fire burned out and it would keep giving off heat much longer than the stove itself.
Check out my other videos. I dont think this makes sense on a small scale
I am not such that I would put flammable material near a stove!!!!!!!!!!
In a proper container, I would imagine it's as safe as you make it.
@@murphyaustin9096
One of the greatest thing about electricity is how easy you can move the energy from one location to another. You can keep your sand battery in one location and use a 12 gauge extension cable to carry the power.
Using just one heater element forces it to get very very very hot to transfer heat to the sand. It risks extream oxidizing sortening it's life. Stove heater elements are better designed for extreame heat without being oxidized. It will also have a higher surface area in contact with the sand.
can the sand crystalize?, like his did, into something that can short the element and or start electrically charging the sand causing a shock hazard. I assume sand is not conductive.... but that does not mean something in the sand might be?
hence why I was thinking some silicon covered heating pads (like drum heaters) distributed thru the battery may be a better choice?
@@coachgeo In short, i don't know about molten sand/glass. I have some educated guesses but I could be wrong.
silicon dioxide I quarts glass and sand is a very good insulator.The DC resistance is very very high and there is probably very very very little current flowing through molten sand, even with some contaminates.
But if you preheat a piece of glass, and stick it into a microwave, the glass will absorb the microwave and melt. This is called dielectric heating. It happens because silicon dioxide is a polar molecule and when Glas is heated it's free to orientated with the changing electric field likevwater does in a microwave. This also means molten molten glass can capacitive couple alternating currents, although I have no idea how much or how little that is given a resistor heating element but my guess is that the surface area at each end is small and 50 or 60 hz isn't frequent enough to dump much energy though dielectric heating.
Yes 👌
@@coachgeo poke the element in from the top to bury the element but leave the wires exposed
@@kreynolds1123
The melting point of sand is about 2930 degrees faranheit. This wouldn't be able to be achieved with what he is using if he applied proper heat transference.
The biggest issue he is having here and the reason the silica clumped to the element is due to the lack of heat transfer. The element was "building" the heat right in the center and in order to keep from concentrating the heat you would need to do some calculations in order to know how much or how quick to heat up the mass in it's entirety.
Also when he molded in a straw so that he could temp probe the mass he just made a small thermal "volcano" where a crap ton of the energy is going to make its way towards, hence heating up the area surrounding the hole first cause the heat to want to escape faster there and not spread homogenously. So the thermal couple between the sand on the element and the energy coming from the electricity in the element was a stronger bond than that of the rest of the mass so therefore it continued getting hotter and hotter. If there was a "cutoff" point in intervals the "hotspot" would have time to transfer that energy to the "cooler" areas hence, making it able to become hotter and more efficient.
This heating is governed by the dielectric properties of the material. The dielectric properties depend on the frequency, and temperature.(With sand, moisture content also affects dielectric properties). The dielectric properties of some materials are mainly dependent on temperature, whereby the coupling is increased as the temperature increases. These materials are prone to a thermal runaway effect that is initially caused by low temperature differences in the material. Those
areas that have a slightly higher temperature than the surrounding material take up more energy due to better coupling to the high frequency waves. This results in a faster temperature
increase, which in turn leads to even better coupling and increased energy take-up, and so on.
This thermal runaway can result in local destruction or even melting of the material. Assuming you allow it to reach over 2000 degrees faranheit.
Great idea, and so glad to see someone thinking out of the modern box.
Just a reminder, Bricks have always (or were) always used in the past. People would take a brick out of the fireplace, put it in a cloth wrap and place that into the bed to stay warm. THUS....
You technically could put that element into a frame with poured concrete, then let it dry, and have a handle built in over top so all you do is carry it. Plus you could make an insulating box to go around it. Even could make the insulating box out of glass with a no air in a vacuum.
As for the solid fused sand, that's what you find on the beach after lightening strikes.
Watch the other videos in the series
@@texasprepperprojectsJust a thought but there likely are many junked hot water heaters that leak(water) but would hold sand. I would also
consider removing the outer jacket and insulation, wrap the entire heater
with copper tubing, and then replace the outer jacket for appearance.
Water could be circulated through the copper tubing, carrying off the
heat that is being lost, and moving it into a second, non leaking hot
water heater.
@@jamespatterson3153 check out my part 2 video for why I didn't do this
Excellent work TPP, you think like I do but we are not Physicist. I worked in corporate tech for 35 years and have performed many experiments many involving temperature measurement of devices. You took all the important measurements and answered my questions. I've had a great interest in sand batteries and this is the first good video that demonstrated practical concept.
Thank you. Check out my follow-up videos for more tests and measurements
I like this. Will start experimenting on it myself. This seems to be one of the cheaper more reasonable ways to create extra heat. Thanks!
Check my other videos for testing
Also, try a “sand hog” element. They are used in water heaters where there is a lot of sediment in the water., they are made of a tougher material and will last longer.
How about putting it on a 4-legged stand about 30 inches off the floor and use a fan to circulate the heat?
Why?
BTW this is great! I was thinking of a cheap and easy way to keep my greenhouse from freezing temps.
Check my other videos for testing
Thank you so much bro, I have uncles in Texas but I'm in Canada were we really need this, I love your heart 💖🙏👌😎
You are so welcome
Love the simplicity
thank you
To make it a real battery (saving heat for when you need it), you will want to insulate the heater. Surround the heater with a thick layer of rock wool insulation and make an insulated lid - when you lose power, take the lid off and blow air across the top.
this is my plan for version 2! thanks for the reply!
@@texasprepperprojects this will work but you have to encase the rockwool because the adhesive in the rockwool will breakdown at 200 degrees but the rockwool will last up to 1000 degrees itself it just gets messy and fibrous after 200. Ceramic wool for kilns does not have this issue.
Blow air across the top with one of those electric-free stove fans...can't remember the technical name for them.
@@texasprepperprojects An0ther 0pti0n is fire brick. Generally, l00k f0r pe0ple making diy kilns.
I’m imagining copper grounding rods brazed to a copper disc and drive them down into the sand to make a giant heat sink. This would wick the heat upward faster than sand alone.
Hey, I really like this idea. I was looking, and an oven heater element is a similar price, but is probably better designed for these sorts of temperatures.
Check out video 3
Nicely done, I built one just 4-5 weeks ago.
thanks
Great research. Great comment section. Need this sand battery and a thermoelectric fan for relief during power outages in the hot desert regions
Nope. If your in a desert, then direct solar-battery-inverter is FAR easier than dealing with this mess
@@texasprepperprojects thanks for your response
I'd like to add my vote to using the heating element from either an electric grill or an electric range instead of from a water heater. For extracting the heat possibly try running some metal tubes (copper or steel) through holes in the bottom and exiting out through the top of the sand/plaster, convection should get air moving through them. Those tubes probably WOULD get hot enough to burn on contact though.
I've decided to go ahead and give this a try. Stay tuned to version 2!
Just use a thin copper plate that goes to the bottom of the pail. Then have a thermoelectric fan in contact with the copper plate. This will have the effect of extracting the heat and blowing it with the fan. There are videos of this here on TH-cam as well.
A countertop, "Griddle", should do the, trick?
Why couldn't you just use a, "crock - pot?"
It's the same thing, basically?
@@galenyoung8349 Crock Pots USUALLY don't get that hot. Not sure how hot it would get if you bypassed all of the control circuits.
OrRunWaterTroughPipes.
Pro tip: Spray the inside of the bucket top with Pam cooking spray to help with the plaster release. Might also try using mortar or drywall mud instead as it's cheap and like cement when set.
Great idea!!
Thank you for this video.
Thank you, also, to those who add information in the comments.
Make sure to check out part 2 and 3 for follow up tests
Great video, thanks and I could have definitely used this during our East Texas Freeze-a-Thon a few years ago, that was crazy, probably not as much sun during that time as we get during the summer, but this looks like a great way to create heat in an off-grid situation!!!
Check out video 2 and 3. I think an electric blanket makes more sense
Wood stove surface temperatures range between 500°-800°F. I could see using some firebricks and a welded steel box. The power requirements wouldn't be trivial but it's do-able. Neat concept, thank you for sharing.
Hi,l'm so very happy to see your video,can i write your compoment that you to built this batery
Thanks for the tips!
Okay, anyone who does this needs to treat the thermal battery like a wood burning stove! Air gap insulation, heat shielding from anything that could be combustible. Radiant heat can, and will start fires a distance from your sand battery.
Please do not set it on 2x4s! Set it on stones, bricks or glass blocks, with an air gap between for air flow. I wouldn't set it directly on top of carpet either. Unless you have a concrete board between to take the heat. My wood burning stove is set a base layer of glass block, then a thin concrete board (shower wall type) and then the stove sits on that. There is plenty of air flow under the concrete board to keep it below 90F.
Radiant heat can (and does) start house fires. So just be careful with it. That includes keeping curtains, furniture and anything else that can catch fire at least 3 feet away from the sand battery.
neat idea
very good experiment,i have been working along similar lines
Thank
Good idea thanks for sharing the information ...
You bet!
Nice video and fun experiment. I think that the large stainless steel surface area is wasting a lot of your heat. Heat is radiating off the pot while you are trying to charge it. That is why the surface of the pot only gets to 90 some odd degrees. I think that you need a fiberglass insulation jacket around the pot while charging, to be removed when you want it to radiate heat. It will absorb and radiate better if you paint the the pot black inside and out.
check video 2 and 3 for follow up
That is so cool.i love it
Thanks!
I've been thinking of doing the same thing, thanks for doing this proof of concept!
watch all the videos in the series. I try several different things and do actual testing later.
Thanks for the information.
You bet!
This is called a storage heater. The commercial ones use thermal 'bricks', computer control for heat release and fans to blow things about.
If you want to power the heating element directly from a solar PV array, make sure you match the load resistance (the resistance of the heating element). It will be about 4 to 20 ohms and this should match the apparent PV terminal resistance at the average sun intensity. You do this by measuring the current and voltage and dividing the two. For a quick guess at the resistance, take the VOL (open loop voltage) and the ICL (closed loop current) readings from the label on the panel and divide the VOL by the ICL. However, the VOL changes depending on if multiple panels are connected in series and the ICL depends on how many panels are connected in parallel.
The reason why you want to match the load and source resistance is for the best efficiency. A mismatch will significantly reduce the effectiveness of transferring solar energy to heat energy.
At the temperatures you measured you are going to burn out the heating element. The highest that element is expecting to get is 212F since all it does is heat water. The alternatives are nitinol wire used in electric kilns and electric bar heaters. It's cheap enough and the good thing is you can tune the load resistance by simply having more or less length of wire since the resistance is just a function of length.
To get the heat out, you could put a coil of copper or steal pipe in the sand and just blow air through is. The air could be scorching hot so be careful. Don't put any liquid in the coil - whatever it is it will probably just boil, expand and blow up.
great technical information!
His nuts, but cool
I plan to try to use the heating element from an electric stove, which can handle the higher temps.
@@SmallVansBigWorld I am going to do so as well for version 2. Stay tuned!
As stated below a stove element would do better. You might consider building two of these if they will heat up in 2 to 2.5 hours and you have 5 hours of direct sunlight. Heat one and bring it into the space you want to heat and have the other one heating. While they are heating have them as insulated as possible so very little heat is lost. Better yet have them in your garage if any wall faces South, bring the wires in thru a thimble to a correctly sized breaker and have pigtails to connect to the battery. Think of it as having two batteries for your drill, while one is running the drill the other is recharging. Doing it this way it doesn't have to wait for a grid down situation to be used. If it is going to be cold Saturday night, heat up the batteries Saturday afternoon, if it is going to be sunny, and let them give off heat as long as they will that afternoon and evening. Means less power from the power company.
Or you could run a cable to both heater locations
Cuánto horas de calor me suministra una botella de 1 litro con agua, y cuántas horas si fuera arena sola 🤔?
check out my follow up videos
Getting positive feedback from Robert is an instant subscribe.
I was going to anyway. U rock.
Thanks!
Excellent project.
A slide stating all electrical ratings and dimensions would help viewers immensely.
Thanks.
Ok, thanks
Please continue these videos on experiments with sand batteries. I've been thinking about designs and the next least expensive alternative. Here are some alternative supplies and materials, and some facts about large commercial sand batteries:
1. For a heating element a single burner hot plate seems perfect. They have thermostat controls, and the heating element could be removed and extended with wires.
2. For an inexpensive metal container there are metal tubs and buckets of various sizes.
3. Rock and some concretes have slightly better properties than sand. They are almost twice as dense, have higher heat capacities and higher thermal conductance. So pieces of those surrounded by sand will work better than just sand.
*If the speed that the sand heats up or the bulkiness of it is not a concern then the information below doesn't matter too much.*
If however, the speed of heating or the overall size of the system matters then the next part might be helpful.
*Other Materials:*
1. The specific heat capacity of sand is 830 J/kg K.
Its density is 93.6 lb/ft3.
Its thermal conductivity is 0.25 W/m K. (Yes, it is that low, so it's very slow to heat up.)
2. The next least expensive solid substance, I can think of, for a thermal battery is Iron/steel.
Its heat capacity of 460-540 J/kg K, depending on the alloy.
It's about 5 times as dense as sand, at 492 lb/ft3.
Iron alloys have a thermal conductance of 15-53 W/m K. (The softer less expensive types have higher numbers.)
3. Aluminum, with a heat capacity of 900 J/Kg K is more than double the Iron alloys but is more expensive.
The density of Aluminium is 169 lb/ft3.
Various alloys of aluminum have thermal conductivities between 150-190 W/m K. (So it heats up quickly.)
It's not a bad option, especially if one is willing to melt it into ingots.
4. Fortunately scrap metal exists, but finding a source and pieces of the right size and thickness might be difficult. Cutting the metal would probably be necessary in most cases.
5. A regular store item would be iron disk weight plates, which are about $2 to $3 per pound.
*Large commercial sand batteries:*
1. Sand has a high thermal capacity, but is a poor conductor of heat for a solid because it is not very dense, and each piece has minimal contact with the others.
2. In the large versions, they get around the poor heat conductance by speeding up the heat transfer with high-pressure heated air. Air is pumped through open pipes that run through the sand.
3. The pumped air method is not feasible for small in-home versions, at a reasonable cost.
I think since sand has these properties, of heating up and down slowly is what makes this works so well. It's more about storage rather than transmitting the heat. An equivalent alternative is water, but that has it's down side, as he mentioned.
@@SmallVansBigWorld . H2O has the best heat capacity for liquids, so sand and water would send the heat evenly to the sand and help have better temperature over all. Thank you @Mavric9000
@@clintw9114 At temps over 100C how long is the water going to hang around?
@@clintw9114 Water would evaporate, so you'd have to seal the container, effectively creating a pressure cooker. So that would be dangerous, without a proper pressure relief valve it could explode.
@@Mavrik9000 .
yes it will go boom if sealed. you are running it uncontrolled, no temp regulation so the element will not last long. The heating element is made to heat and be cooled by what is is in, if it is on max at all time they will only last so long, if you add a temperature regulator to it so it stops at 200f it will last years. At 200F just under evaporation of water the sand that hold more heat and fully heat up and the water will help add heat to the room faster. I have had to deal with this type of element in oil jacketed and water jacketed cook pots, holding lines, they fail fast when dry. I hope this helps. If you do add water please make sure the back of the connectors are out of it there are live and that is why the sand seemed to melt around them, they could of been arcing. They are made to be out in air. Don't need any one getting shocked.
Instead of plaster of paris, use the high temperature ceramic bricks that are used to line a fireplace, chimney, or brick oven. These are available at home improvement stores like Home Depot, Lowe's, etc. You could also use those type of bricks to build a base to set the pot on.
PS there is a commercial grade version being tested in Finland, and the article said that the sand could be heated to 600 C (1000 F) before it melts.
Nifty
Question: Once sand melts, is it a better conductor because it now has more density?
Thank you for the idea! I didn't know that you could run a water heater thingy on the lower voltage. I had been thinking of going to the dump and grabbing an old water heater and filling it w/ a couple hundred pounds of sand. However, once it is filled, that is where it stays! Also, if any buried unit failed, a real bear to remove and replace. I LOVE the idea of using old finned radiator coils, I would use old A/C fins and just pump air through them.
It's possible to run lower voltages but remember you'll get a much lower wattage/heat output
retired plumber / pipefitter just looked up large container's like small silo which I can foresee lots of ways unused heat could be trapped. thanx TPP
Very cool!
It is extremely well done ,you should definitely finish following up I was so much expecting that follow up that I will Subscribe to your channel just to see that follow up Thank you so much and we will be doing this experiment also with some twist of our own again excellent video can't wait to see more.
Thank you!!
I've just been turned onto this method of heating and I think using an old hot water tank would be a great container. They're insulated and they even have a pre-installed electric heating element. I'd be happy to watch you make it first. LOL!
check out my other videos for testing and builds, as well as some questions answered
hot water tank is optimal but you don't fill it with sand you fill it with water.. search solar hotwater heater on yt .. its a better solution.
@Zippy TheChicken Interesting to continue using water in the tank rather than sand. Does water retain heat as long as sand? I know sand and stones have the ability to capture heat and hold the heat for a long period of time. If water has the same heat retention, then there is definitely no need to fill it with sand.
Electric hot water heater elements need to be in water or they'll burn out pretty quick.
@Gene328 Thanks for the insight. Just to clarify, I was only talking about using the hot water tank as the insulated vessel given its construction. I always assumed a different and more robust heating element would be needed as opposed to the stock heating element.
Cool idea, keep experimenting and improving. 👍
Thanks, will do!
Merci from Montreal, Canada.
Hello there!!
Hi, Nice project. You could turn the pot upside down. Make an entrance at the bottom for the thermometers and the heating element. They Will be at the cool bottom side and the warmth will be trapped on top. No chance of any heat to leak through the lid. Secondly add insulation on the sides and insert U shaped tubes from bottom to top and back . Blow cold air through the tubes to extract heat. So you control when you want it. Use air to extract heat. With a fluid is more dangerous because it will boil. Extracting heat allows you to setup the sandbattery stationary elsewhere and increase its size and capaciteit. The Hot air could be used to heat a secundairy heat exchanger Linked to a central heating system. You will have thus more control over the maximum temperature in the secondairy heat exchanger.
He is dealing with so much heat in some spots, he might have a problem with oxidation of metals. But maybe he can run some copper pipes down the outside and coil inwards along the botyom and drill some holes on the bottom of the copper coils and force air through slowky and let the air filter through the sand.
If he had a more distributed heating element with a larger surface area, a mineral oil could withstand 500-600f. It would fill the airgaps reduce prevent oxidation of metals in the heating element and better distribute the heat to the entire body of sand. Downside is while it may end up holding more heat, the sides would get hotter more quickly and it wouldn't hold the heat as long.
maybe
Good video ! I haven't read trough all of the comments , but I've seen some god suggestions for improving the sand battery. I would suggest that you get rid of copper water heating unit , because it will fail shortly at that temperatures and go with stainless steel ones (like from hot plate , or (even better) small electric barbecue grills - bigger heating surface) . Other suggestion would be to drill holes in the bottom of the caldron and to make electric connection outside of the sand container and prevent wires from melting and burning. You can also make hole for thermometer on the bottom too (with some insulation between edge of the hole and heating unit and thermometer probe). Also , fine sand works better (like silica sand) and couple of coils of flex metal hose (about 2" diameter), within heated sand , will do great for convection heating (blowing hot air) , with a small fan on one end.
I would skip the electric heaters altogether and use a solar hot water system instead. That would allow the sand battery to be tied in to a radiant heat system throughout the house.
@@kmoecub it is not comparable temperature vise. Also , hot water system is a - system , while this can be stand alone unit (and portable , depending on a size and weight).
Flex metal hose is a great idea!
agreed
Great video, thank you for sharing
Thanks for watching!
Very cool, thanks for sharing! Just subscribed!
Thanks!! Check out my other stuff!
If you decide to give this another go, next time, you might want to get some heat resistant piping (preferably something flexible) and then thread it through the sand. Have both ends poking out the top and then get a small fan to blow air through the piping. I bet money it would generate a nice warm, directable stream of air instead of just having to rely on just the radiative heat it's generating.
Watch my recap video for more details about v2
Why not use a stove top coil heating element? More surface area.
Check video 2 and 3
I use to build conveyor belt dryers with ceramic heaters. Your element melting problem is similiar to some problems we had.
Biggest problem was at wire to element hookup.
Cure was high temp nickel wire and high temp crimps from wire to elements.
I switched to silicon wires
I certainly hope that we come up with something soon for practical use. We can't depend on outside entities to keep us safe or secure. We need to step up and make it happen ourselves.
Look around you, can you communicate with your neighbors. Speak the same language?
The infrastructure of this nation is in a great state of disrepair, decades, of neglect.
You are the only solution to the work that needs to be done.
Thank you for posting this video. We will have to experiment on all facets of safety, security, health, and comfort. Make it happen!
Thanks!
this is really good , just please don't forget that sand expands a lot because of quartz in it , also sand as an element expands since I remember 5% expansion so if you put a cover that tight to it , it could explore in the worst case of just split your pot ! be careful
check out my other videos for testing
Sand shouldn't expand at all, right? Isn't it glass?
@@tehapu7358 no, it will expand, it's the law!
heating element should be install through a hole in the side or maybe cemented into the plaster on the vertical, so wires are not in contact with hot sand this would overcome some issues you have with shorting out or melting, there are a few ideas i could give on better heat transfer but this would require more detail than i would like to go into right now, overall good idea
Check out video 2 for my reason
Thanks for sharing 👍
Thank you too
I was looking into sand batteries for a while and I liked your experiment. I was also thinking of heating the sand using the solar concentrator lens which may come at a lesser cost and faster to heat than the solar. It can takeout the possibility of wires burning up inside the sand. The metal fins can be embedded inside the sand like you mentioned with its tip exposed out at the center of plaster of paris to which the solar concentrator will target to heat and transfer that to sand?
Check out my other videos in the series before you do. I tested a lot of things
Use a little fuel to raise the temperature initially. Use a parabolic reflective surface to direct the heat to where you want it. Make sure it covers the top. So hood it.
Check video 2 and 3!
Well between your information from the video and also all the information in comments the idea popped into my head is to make like three separate sand batteries and then put them under my RV and then insulate with a pink foam around around the RV would work great and being the metal container in contact to the ground the ground would also become a battery under the RV so the sand battery only has to be as big to hold the heating element this way you could run only the bedroom area overnight off batteries and and program the living area to come on and shut bedroom off couple hours before you wake up couple of solar panels will always be cheaper than having to buy propane to run the big buddy because I am using one and through a three-week cold snap with lots of rain I burn through a 20 lb tank pretty quick.
Sit tight for my testing of version 2. Might be of benefit to you
Ty so very much for sharing your experience and knowledge.
You may save lives.
God-bless you and your family Brother 👪 ❤️ ✝️
Welcome!
great simple Idea 💡 😊
Thank you! Cheers!
I think the biggest design challenge with heated sand is the wire insulator and element insulator melting. If they have ceramic insulators, its fine. You need high temperature wire insulation inside the sand. Also, crimped connections will live where soldered connections will melt.
The beauty of this is that you can keep the sand indoors and insulated and put in a temperature switch that cuts off the electricity before the components fail. You could put an insulation blanket over the sand container to regulate the heat into your house. You could also use a thermostatically controlled fan to turn on automatically to control the room temperature.
You could charge a battery with the solar and when the battery is full, dump the remaining heat into the heat battery. Then use the battery to run a fan etc.
Its good that you tried something. Most times all I see is someone buying an expensive gadget and doing a review.
Check out my follow up videos
technically since sand is not electrically conductive you can have exposed solid copper all the way to the heater contacts
@@robertjones1730 true
@@texasprepperprojectsno, don't do that, because then you reduce the resistance produce less heat within the sand and transfer the resistance to the wire or fuses which will melt
Just drill a hole in the side of the pan and put the element through there. Either that or buy a tank designed to boil water with a heating element that can withstand the heat of boiled sand...
Insulate [the exterior of] the bottom, to avoid scorching the surface underneath, with Rockwool maybe over cement backer board. Also, add a removable insulated lid over the top, and maybe some aluminum fins as you suggest.
stay tuned for rev 2 coming soon!
@@texasprepperprojects I meant the exterior. I made that edit to avoid any potential confusion.
@@texasprepperprojects Also, an oven thermometer or one of a higher range would be helpful with these experiments.
@@Mavrik9000 Agreed. That's why I bought that meat thermometer, which I maxxed out!
@@texasprepperprojects Amazon has more than one analog deep fry probe thermometer that goes up to 500°F for under $10.
I am interested in the idea and it would be good if practical designs were implemented to be used in homes and other facilities. In any case, your efforts are appreciated.
Watch the other videos in the series
Nice work man!
thanks!
Beautiful work here! Thank you for your share! In a future project, you might look into aircrete in place of Plaster of Paris. I'm considering tubing and a compressor to dump heat from a server and a turbine to convert it to electricity. The server converts 3kW to heat, and I'm wondering how much I can convert back. Sand can take 830kJ/kg/°C. I'm planning to run the heat from the server into the compressor, then the sand battery, and then the turbine, the exhaust from the turbine then goes through a vortex tube resenting the remaining heat back to the loop and the cold into the server. My ultimate aim is to process 1MW or 2MW. It will be very interesting to see how much electricity I can recycle.
I think i'm going to use concrete for the next build. It's actually cheaper than plaster of paris
Now you have me thinking of possibilities. Let us know how your work goes. I think you're on to something in regards to small scale/business waste heat recovery and power generation that would work well in the suburbs and rural areas.
Maybe run a coil of copper pipe in the sand then circulate water through a radiant baseboard heater. I think going a little bigger would be better. Make a stand to keep it up from the floor. Make it so the elements thread into the bottom then the wires would not be in the sand. The only issue is powering the circulation pump. Would be a really cool project. Hopefully it wouldn't boil the water and pressurize the system.
Check video 2 and 3
Well done.
Thank you!
Hey Scott that was great video about making a sand solar heater I'm here in Texas coldspring Texas and I run my whole house off solar and 12-volt system so man you you open my mind up to a cool thing cuz I only have a buddy heater and now it's showing how you can do this thing with sand now here's another idea I got you could put that pot on some cinder blocks and then blocks get hot from the pot to and they would give us some heat that's another little way of looking at it but yeah I like the way if you take the top off and let the heat run out and then you can possibly put a 12-volt fan in there and get more heat out of it so man great video man thanks for sharing it I'm looking forward to seeing some more of yo videos
Check out my follow up videoes
Very interesting. Though of getting a aluminum water trough used for live stock, filled with sand, and use multiple heater laments. You can stick steel rods or angle iron in the sand as radiators. Could go as far and placing some ducting over the radiators and a small house fan to push heat into the home?
check out video 2 and 3 for testing of this
Well done, my concern would be the wires. they were made to be out side the water heater and not subject to such high heat. maybe drill a hold in the side and install like in a water heater. just my thoughts.
Check video 2
I'm in the Greenville area I know you're "cold". Love the video. Great DYI.
Your stated solar panel production in factory spec at 70 degrees. Expect a little less. You should still make your goal though on most days.
Suggestions: to hopefully prevent sand making glass at the terminals add paragin wax to fill space between sand grains and also take advantage of phase change increased thermal capacity and discharge time. Playground sand will have less room fir wax than coarse sand/beach sand.
Set the pot on a cast iron trivet or a low rot iron plant stand.
Convert a defunct 40 pound or bigger propane tank or heavy/thick galvanized steel trash can. Furnace bricks on bottom or your plaster of paris.
Set heating element vertically in center and try to get equal distance from top and bottom of element as distance to walls. Thus, the suggestion of propane tank. Heating elements come in a lot of lengths. A little math will give you the optimum length for the actual container you choose.
You need more thermal capacity than you can produce. Not much, but more. Once the system is saturated things will start to warp, melt, rupture, go south. Add a loth of extra insulation to the wires. You need more protection than your theoretical may temp. Or, seperate the wires and chase out of the vessel on opposite sides. The sand and wax are non-conductive so bare wires are no big deal as long as they can't arc at the element terminals. After the first run, this isn't an issue as the new glass will prevent it. But, until then, you could short the system and fry your electronics up stream.
Radiator fins on the outside might help. Or, burry a thick wall cpper coil in the sand and circulate fluids to a used truck radiator with the OEM electric fans still on the housing (step down the fan speed). This could branch off and heat multible bedrooms through the night.
I love your idea. I wish you all great success. This is just me spit balling some ideas while driving home from work. I hope some it might help and that it all makes sense.
check my 2 follow up videos for reasons why I did what I did, and testing of those ideas
I have also the same,but i did put a heatpipe in the sand connected to my radiator. The heating element is from old boiler 60 ltr and fitted on the lid so the connection is outside. And the bucket is isolated with clay and alu foil.And using a converter from 12 volt to 60 volt.
Neat
Seems to me such a thing is most valuable if you have a space you'd like to keep from freezing (like a grow room under LED lights) that gets no direct sun. You could put heat battery in the grow room and the solar panel a good distance away where the sun shines. It's not obvious to me how you'd convert the heat contained therein into electricity.
Well done.
A Peltier element will convert heat to electricity or vice versa.
Peltier element or steam turbine or steam motor for mechanical power. But its most efficient when used directly for heating
i'm already using solar
I'm already making electricity with solar
Why did the insulation on the wires near the heating element not melt?
great question. i dont know
This is cool. Thanks
Thanks for watchin!
I like it, but I was thinking, maybe can make use of crock pot.
I actually use toaster oven, espresso/coffee maker, rice cooker, boil hot water, using my 200AH lithium batteries and 400W Solar Cells, can generate actual like 275W. I'm in New England area, so I'm sure you'll have no problem once you get this sand battery concept down. If portable you can paint black and also just leave in the sun, and compliment with solar cells. Then roll into house.
In rev 2 I'll use a trash can with thinner walls. I do think that if you have direct sun you can 'boost' the heat in the sand on top of the electrical heating.
Hello! Very nice video! After seeing Finland huge sand battery I quickly run is there any smaller one for homes and I found company from UK which make 'WarmStone' sand battery which can provide heat for 2 weeks or even more! Very interesting idea and I think it will be a future.
get 1 or 2 55 gallon drum, fill them up with sand, and put a bunch of heating elements in for using solar electric... OR run a copper coil thru the drums if you are using solar heating panels, circulating antifreeze solution thru the copper pipes... theres probably a way to heat the drums using solar air panels as well but it would take some engineering
It's a fun idea
This is a nice project but needs to be scaled way up for anything larger than a small bathroom. Looking at the panels I estimate you are heating the sand at 200 watts max.
200 watts from 5 hours of sun is 1,000 watt hours or 1 kilowatt hour which is equal to 2.5 ounces of propane. If bulk propane is $3.00 a gallon that would cost $.011 if you buy 1 lb. cylinders it about 7X or $.77 worth of propane. (about $0.10 to $0.25 worth of electricity depending on where you live) .
This is true. Check my other videos for more information
I’ve a similar idea using an electric smoker I bought off a local auction for $5.00
This year for thanksgiving sales I invested in solar panels and battery.(battery for propane furnace in case of outage).
The smoker has heat control where it will cut out at a certain temp. Copper tubing will distribute the heat through the sand as it can be used for directed air or even water.
My 2cents
Great vid!
Full setup showing solar panels coming soon! I just need to wait for the sun to come out!
Figure out how much power you gain approximately per day. Divide that by 12. That’s how much power you can use every 2 hours in a 24 hour cycle. Match those numbers with a long lasting heat source. Match those numbers too the right size sand battery. Make the heat rise after charges so that fan can disperse the heat until the heat is gone. You will need a high cycle battery too complete the system but I bet it’s quite efficient. I feel like your idea is linked too efficiency in some way. I love thinking about these things. I got a 98 in advance chem at one point before I left school. Would love to have a chat with you about it 👊
I think that this is about thermodynamics and heat gain.. and what the best way to release that is. The 500F temp I got was nuts, but it needs to be released slowly and in an intelligent way. Stay tuned for rev 2 and rev 3.. But feel free to email me to discuss more!
@@texasprepperprojects ok. I just subbed. Will stay tuned. Have you thought of making the sand hourglass out after over time? Might be an easy may too time release the heat.
@@texasprepperprojects super cool topics 👏👏
@@texasprepperprojects heated sand waterfall? 😂
I would personally use the PV panels to heat water in an insulated tank so you could then either use it later as domestic hot water or pump it around radiators to produce room heating. Yes, sand holds more heat but hot water is far more usefull in a domestic situation in my view :)
stay tuned...
Sand actually doesn't hold more heat. Water has a specific heat over 4 times that of sand. The sand would have to be almost 850 degrees to hold the same amount of energy water does at 190.
We assume that water holds less because it's far more conductive and produces steam that cools it off quicker.
The only materials that have higher specific heat than water are liquid hydrogen, liquid helium and liquid ammonia. For obvious reasons none of those things are viable because of their silly low boiling temperature.
If you want this demonstrated for your self take an infrared thermometer on a hot day and find some sand on the ground that's 140 degrees and touch it. It will be hot but will cool off almost immediately because of shade/dispersing it's energy into your hand.
Try this again (don't actually try this again) with 140 degree water. It would be very painful and you would get 1st/2nd degree burns.
@@W1ldSm1le
Exactly as you said, I've done calculation and at best, for the same volume, sand will hold 12% more energy. It is however not worth it, besides the complexity of doing it and high temp risks, energy losses will be far greater then extra 10% energy stored.
Sand doesn't explode like steam will so I'm makes the whole system a lot easier to design and maintain.
This would be amazing to offset insane heating costs in my cabin. Have a stove I could set it on that is gas and made to radiate heating. Fantastic job man! Would love to see any updates on this as a system.
Check out my other videos. Short version, it's not worth it. Can you do geothermal?
Good to know, and great thought. Appreciate it. It’s super rocky soil out here and a big water table 40 ft down, so geothermal would have some big challenges here.
Oh, this maybe a great idea for outside dogs during the cold months!
could be!
This is a very cool experiment. One thing you don't explain well in this video is the relationship to heat/temperature and energy density. You mention the higher potential of heat storage for sand vs water, but not the caveats that come with it.
First, the amount of energy a substance holds predicts how much energy it takes to heat that substance to a certain temperature.
Water holds roughly five times the amount of energy as sand per unit of mass. So at the same temperature and the same weight, the water is holding 5 times as much heat energy.
This means, you need to either use 5 times the quantity of sand to make up for this, or raise the temperature of the sand by 5 times to get to a comparable energy density.
Sand can meet this requirement. I will use Celsius as it makes seeing the relationship easier in this case. Water boils at 100 C under normal atmospheric pressures. Sand melts at roughly around 1500 C at the same pressure. So, you can store 3 times the heat energy in the sand vs the water, and sand is as cheap as water, practically.
Here come the buts.
1) Do you have anything that can hold the sand at that temp?
2) While letting you get the heat out without melting the transport medium?
3) What temps do copper and other pipes start melting?
4) What temp will the element start melting?
5) Can you hook it up to a heat pump instead since they can transfer heat more efficiently?
6) Will you use water or air to transport the heat?
7) Why did I mention atmospheric pressure?
The answer to 7 is, we can change the boiling point of materials by changing the pressure they are under. This is the trick heat pumps use to work more efficiently. It takes less energy to bump up or down pressure and let the steam move itself than to pump the liquid. And liquids can hold more energy if you put them under more pressure.
So, in homes where we already have water pipes and storage tanks, where we have the tech and products, and we can pressurize water to boil at twice the temp, we can achieve similar results to what is practical with sand.
Now, in the world of large scale installations, this could be different.
Copper melts at 1084C, common alloys likely lower, iron a bit higher.
The pressure required to double the boiling point of water is 225 PSIA, about 15 times the pressure at sea level. That isn't 'residential tech, or products,' it's 'cutting people in half with live steam when a coupling fails' pressure.
@@Struthio_Camelus I agree it is not ready for home use, but we can use that feature of pressure to store more energy in water.
At safer temps than 1000C, which I didn't even remotely address.
Copper also starts to warp and bend at much lower temps than that, so would it get compressed from the weight of the sand?
@@NdxtremePro I don't now how sand would behave at those temps, but if it's a concern, I'd cast concrete or refractory cement around the copper tubing.
Thanks!
Sand starts fusing into glass above 3000 deg F. That is a sure sign that your heating element was WAY too hot! That heat degrades the life of of the heating element quickly. It's a sign that the heat is not conducting through the sand quickly enough to keep the heating element in a reasonable temperature range.
Some ideas to consider that will help spread the heat out - which will heat up the sand faster, and extend the life of your heating element:
Screw the element into a the center of a large round metal plate that is ~1" smaller than the diameter of the pot. Make sure it has a solid contact with the metal with a large nut. The thicker the plate the better. Thick plates may get expensive, but multiple thin plates will work fine. This quickly spreads the heat over a large area and lowers the thermal resistance to the sand, heating it up quicker.
Use multiple heating elements connected in series, or parallel if the panels can handle the low impedance. 2 heating elements cuts the power to each element in half, lowering its max temperature, extending its life, and helping spread the heat out over more area.
It would be best if each heating element had its own heat spreading plate, but if the elements are electrically isolated, they can be mounted on the same plate.
Instead of a water heater for your heat source, consider using coil heaters for a stove top. These have a lot more surface area than a water heater loop, and naturally spread the heat out more. You can stack several layers vertically in your pot, each separated by an inch or two of sand. They are pretty cheap and readily available.
I'm not sure how possible this last one is, so it may not be practical - it could take some investigation. It would be great if the heating element itself could be solidly attached to a metal heat spreader. Perhaps crimping on some aluminum flashing material. But I would check first to see if their is a voltage drop across the SURFACE of the heating element when powered first. If there IS a voltage drop, attaching plates to the surface will just short out the element, and possibly melt the plates with the current going through them, so check for that first.
In case you're wondering, no, I have not built one of these before. However, I've been an electrical engineer for over 3 decades, and spreading extra heat around safely is a regular part of my job.
Good luck on your next build!
fun ideas, thank you!~ I am integrating some of these ideas. I'm also trying to stay on a bit of a budget for now so people can follow along. I do think that a 'heat sink' will help spread things out. @desertsun02 Just used copper strips, but I think I have a better idea. More soon
I am a Solar Thermal specialist. I live in the Midwest and deal with higher heating loads than you do in your area.
I have taught and given talks on Solar Thermal systems and designs.
Here is my advice.
You can capture or harvest more Thermal energy using Solar Thermal panels or collectors instead of using Electric panels and converting.
A Solar Thermal collector is more efficient per Sq ft of area than an Electric.
Electric is now around 20 % for a good one and Thermal is around 50 to 80% efficient because it is capturing Infrared energy from the sun instead.
Many years ago I helped a man stack concrete blocks in his basement as a Solar Thermal battery. We ducted hot air from a collector through the stack. It worked very well for short term storage.
The higher the differential in temperatures, the less efficient the heat transfer is putting it in there.
It is quicker to transfer from the hot source to the cool source but it means that you need to have a much greater amount of insulation to keep it stored without losing it.
Go to a larger amount of storage medium and build your own Thermal collectors. Keep storing your excess Electric in batteries and then the overage into a Marathon type water tank. It will be more efficient and cheaper in the long run.
High temperatures mean high losses.
What are you using as a collector? I'd love to learn more! I've seen several designs out there for solar thermal hot air collectors but can't decide which is the best one.
@Texas Prepper Projects you can easily build your own using aluminum water heater or dryer vent piping, old cans or even Aluminum panning or sheet metal.
You just need to use flat black high temp stove or grill paint to coat it to absorb the sun light. Find and use foil backed Isocynurate insulation that is high temp rated. It won't off gas.
Build the collector with a back pass air flow or through the duct or can air flow.
You can also use a flat plate designed with water running through pex pipe.
I built some collectors years ago with copper and pumped food grade mineral oil through them with an expansion tank in the system.
Never had to worry about freezing or Boiling as long as it was moving when the sun came out.
There was a really good collector that I helped with in maximizing output but the company that made them is now out of business because the owner passed away.
They were called Sunsiaray or Northern Comfort panels.
They used a special coating on a copper sheet that was kind of like gun bluing. It was 83% efficient at capturing the sun's IR waves.
Black paint is around 65% efficient.
Look up Cansolar.
theindependent.ca/news/how-to-build-a-pop-can-solar-heater/#:~:text=A%20pop%20can%20solar%20heater%20is%20an%20air%20heater%20that,prototypes%20and%20large%2Dscale%20units
Run the exhaust from your buddy heater through a pipe that runs through your sand battery
why?
@@texasprepperprojects to collect and harness waste heat
I would suggest using cement board instead of wood to create a trivet to set it on. Not a lightweight solution but it would not burn or melt.
That was my thought. Cement board or similar.
Agree
Agree
This is very cool! Pretty sure you gave me an idea to help extend my seed start season in my greenhouse. (zone 4b Canada)
And that is a great use for it. But check out my other videos for more data
@@texasprepperprojects Indeed. I watched them. Rather disappointing for what I wanted to do. Awesome vids btw. Lots of work went into doing them.
@@tammy-lynnstewart5677 I have seen people have success keeping their small green houses stable with a 55 gallon trash can full of water though. Water has a good thermal mass
@@texasprepperprojects I wonder if a fish tank heater and a small fan (like the ones off desktop computers - just enough to move the heat around a bit.) would make it even more efficient.
@@tammy-lynnstewart5677 Not worth it. But you could use a thermal solar tube heater with a fish pump to raise the temp pretty easily on solar.
Have you ever seen a Swedish sleeping closet?
I built mine out of PVC and an emergency camping blanket. Using a 45° connector for an 8" length attached to the wall with conduit hangers. Then used boiling water to curve the pipe for the arch.
Bedtime - flip the arches away from the wall - toss the emergency blanket on top - set up the ceramic fan to blow in - sleep snuggy withe the furnace set just below 50°
Fold it all up in the morning 😀
I tried to google this and didn't come up with anything. Please link a video to this idea.
I'm not sure if water heater elements will last long. They are designed to be immersed in water, and they will burn out in short order if run dry. Electric burner elements should be more reliable. I'd also suggest using wire leads that are insulated in fiber glass for the heat resistance. For a lid, using a lid the pot came with should work better than one made out of plaster. They made lids with holes if you want to try that. You can drill holes in the top of the pot and put rubber grommets in the holes to protect the wires from the sharp metal. You could also use a high temperature thermostat to switch off the element to keep the sand battery from overheating. If you use any insulation in the pot, fiber glass or mineral wool insulation would work the best.
Agreed. Check video 2 and 3
A small but perhaps very important detail is to use some wire heat shrink around the screws where the wires connect to the heating element. It probably melted the sand from there potentially being a short through the sand. This will give you longevity to your installation.
Keep up the great work, hoping to see this on a even larger scale soon! I have 55 gallon metal water barrels that I use 120v heating element to heat the water for inside my greenhouse. Connecting 2 large solar panels in series gives me 80-90v and it works perfect.
I hope this video goes viral. People need to see this. I only found out about sand batteries recently.
agreed on this. I'll improve on the next one
I don't even know how the wire insulation didn't melt at these temperature.