I would conserve the sand battery heat by placement choice in my home. It's an old 2 story with basement and large central brick chimney column. In the basement 1\4 of this chimney column ends at a sauna room, and shower. I would put the sand battery under the sauna bench, keeping the wet rooms dry and preheated.
Hi Brent, you certainly have an interesting house. Indeed the sand battery can be applied in this way and be closed after the sauna visit to conserve heat for the next time. You can charge it with the gasoline generator exhaust gas, which is at a high temperature.
Hi Brent, those are not on the same dimension. The sensibile heat is complementary to the latent heat. The former is the heat that raises temperature and the latter doesn't. It will rather melt or vaporise a substance while temperature is constant.
Can you explain how the phase change materials work in this instance? I have seen sodium acetate used in hand warmers used to store energy - but once the liquid is 'activated' it is an irreversible reaction (unless re-heated). The ideal scenario is to have a phase change material in which a chosen amount of heat can be extracted on demand without depleting all of the stored energy. I'm looking at storing heat for daily use to run warm showers, so trying to find the best heat storage medium - sand is good because it is easy and safe (easy to contain, no danger of steam build up - and storing heat in water has potential for legionnaires disease). It doesn't matter to me if the system is inefficient so long as e.g half a cubic metre could store enough heat to run 3 or 4 showers per day with the cold water going through a heat exchange in the sand battery. so can anyone recommend a better storage medium - especially given that the system might have to store energy during wintery days when there is not a lot to heat it (it will be heated by solar).
Sand is a good medium because it can go up in temperature. But ,Phase Change Materials (PCM) are better, because they stay at a temperature that you desire (look on ChatGPT or tables on internet to look for the right material) while storing heat. Sand goes up in temperature if you store heat and thus also the heat loss. I would look for a PCM of about 70 to 90℃ for shower water, in the second sand video I mention a kind of mixture of two salts to choose a good temperature but look on internet. Do you have biomass that you can use for a fire and then the exhaust gases go into a second heat exchanger in the sand, to heat it?
@@nnvasen-good-energy Thanks for your reply. As you say, sand is good because it can be heated to very high temperatures - but the problem here is that you don't really want sand at 100 degree c plus in a shower - there is going to be extreme high pressure in the pipes when not running and also the potential for someone to get in the shower and turn on boiling water. I can obviously add a thermostat to the system to prevent this - but that slightly defeats the point of using sand. I still don't understand how the temperate of salts are managed -- is it the case that if, for example, they are heated to 80 degrees c, they just keep absorbing energy which can then be released simply through running cold water through the mass in the same way you would with sand - but they will take much longer to cool down because it is not just about the inherent heat capacity of the material, it's also because they have changed phase and the temperature of the heat exchange is what determines the phase they are in? I'm not a scientist as you might gather - more a keen DIYer trying to figure the best way to do this - thanks again.
Hi Simon, I don't know if you read this after 11 days, but you are right about how Phase Change Materials (PCM) work. You have interesting ideas as a DIY, you would be a good participant of the English Facebook group, it is a bit silent there! And your comments would not be burried in the timeline of TH-cam comments, and be more visible. If you like, you can visit facebook.com/groups/1440674419825846
Does that happen in molten state? I will have to look up the temperatures for the single salts. I am not so fixed on this exact temperature of 140 degrees. Thank you for information us!
@@nnvasen-good-energy yes I have read that after a little use the salts may separate and thus lose the phase change. Ik wacht met interesse. Mischien zal het een goede uitslag hebben voor U.
If built with a 3x3x3meter= 27m2 sand battery which is insulated by 50cm rockwool. Used with 45 solar panels to heat while sunny, using a 6 kw rocketstove as a mass heater while no electricity, and using electricity while low price. Would this work in Norway in a passive house with 130 sqm? What if I were to replace the sand with water? What about using a heatpump to heat the sand/water with electricity?
Hi Kay, yes that should work. For each m3 sand and temperature of 400℃ above room temperature you should have 100 kWh of heat. I find it very nice to make a hybrid sand battery and such a big one! Now you have 2700 kWh and if your home needs 13 kW (cold country like Norway) of heating in steady state (comfort temperature already reached) than you have 200 hours. If I remember well, then filling the gaps between the sand grains with water will increase its heat capacity by 50 - 100% but its max temp becomes 100℃. I would instead put the heat pump in another system like in my last video 68 and enjoy the very high heat capacity of water, over 4x that of sand. It is also better because fire and electric resistors go very high in temperature (sand) and heat pumps are very limited (good for water). You will have two systems for different temperatures. People will envy you!
Great suggestion! I am also fascinated. However, you need really tons of weight to have a bit of energy. I was visiting Energy Vault in Switzerland, they do it at large scale. Anyway, would like to do something. Like grandfathers clockwork!
You can see that in especially in the previous video 66 (th-cam.com/video/d5zn3u5-ypQ/w-d-xo.html) where you see the small sand battery under a single PV panel of 100 W. Also in this video th-cam.com/video/57ZLgErL_Io/w-d-xo.html you see that it is heated with PV energy, because there is at some point beyond 7:40 minute a display that shows how much is going from the 6 kW PV into the batteries and the whole household. Thank you anyway for your appreciation! If you like to see other themes, tell it me.
You're wasting your time using sand, unless you can rapidly heat it above 300°C. You are able to store more sensible heat energy (40°C+) in 1kg of water than in 1kg of sand. The specific heat capacity of water is 4.18kJ/kg/K whereas sand has a specific heat capacity of 0.835kJ/kg/K. So 1kg of water heated to 90°C would release 209kJ of heat energy before it reached 40°C. To do the same with 1kg of sand, the temperature would need to be increased to 300°C before it was able to release the same amount of energy before it reached 40°C.
You are right, it was what I replied on another comment on that same question. I even told that 350 or 400 degrees is the break even point. The advantage of sand is when you need the high temperature during consumption.
You are obviously right - but sand have three points for it: 1) it can go even higher than 600C 2) its density is higher than water by 3~4 times, so the thermal mass would be much more compact... So in qubick meter you can store significantly more energy in sand than in water (going high with temperature) and 3) it will not explode on overheating (which is also difficult with sand, but you can easily boil water - so you need to have additional safety circuits/devices).
@@dempseypoland Sand has a ~50% greater density than that of water. A simple Google search would have told you that. The issue with heating sand to such high temperatures is that unless you can do that rapidly, you lose large amounts of energy to the environment. It's simply not possible to heat sand to those high temperatures quickly enough in a domestic setting using electricity.
I partially agree with the available electrical energy to heat the sand. The sand will continue to get hotter as long as this electric power is (much) bigger than the loss. The loss can be calculated with given temperature difference and insulation parameters. Moreover, this video proposes to pick up the heat loss at the outside and consume it. In that case you don't even mind so much when heat is leaving the storage (the former "loss" ) but just that the available electric power is bigger that than what leaves the storage.
@@nnvasen-good-energy Have you tried pool filter sand which is pure silica sand? It has a much higher thermal conductivity. I’m testing a large 6ftx8ftx2.5ft under a greenhouse. I also mixed granite stone with the sand. I haven’t fully tested how hot it can get but I did get it up to 108°f and dropped to 79.9°f after 3 days of no additional heating.
Hi Veronica, yes, I saw it in the comment below of Sytonic. I couldn't believe it. I saw your video about the dead wasps, amazing how it could happen. In which country are you?
I thought so, that you were in Europe, because of the European Juggling convention. I hope you like the channel, if you like to see treated a theme, just tell me. Greetings from Sicily.
This entire practice isn't going to work. The more you recover the heat from those channels, the faster the heat will be lost through the bricks. The math just doesn't work out on any of these things. The most advantageous option is storing heated water in a dewar flask.
Hi Dus, I agree with the dewar flask (where we keep warm the coffee) principle but who will make this for us? You can use a refrigerant vacuum pump (I have it) but you need the double wall, leak free. I agree also that the heat will come faster through the wall as you suck it away and use it, but much less will go away through the second wall (the outer wall). Only this latter leakage can be called "loss".
I would conserve the sand battery heat by placement choice in my home. It's an old 2 story with basement and large central brick chimney column. In the basement 1\4 of this chimney column ends at a sauna room, and shower.
I would put the sand battery under the sauna bench, keeping the wet rooms dry and preheated.
Hi Brent, you certainly have an interesting house. Indeed the sand battery can be applied in this way and be closed after the sauna visit to conserve heat for the next time. You can charge it with the gasoline generator exhaust gas, which is at a high temperature.
What's the difference between stored heat and sensible heat ?
Hi Brent, those are not on the same dimension. The sensibile heat is complementary to the latent heat. The former is the heat that raises temperature and the latter doesn't. It will rather melt or vaporise a substance while temperature is constant.
Can you explain how the phase change materials work in this instance? I have seen sodium acetate used in hand warmers used to store energy - but once the liquid is 'activated' it is an irreversible reaction (unless re-heated). The ideal scenario is to have a phase change material in which a chosen amount of heat can be extracted on demand without depleting all of the stored energy. I'm looking at storing heat for daily use to run warm showers, so trying to find the best heat storage medium - sand is good because it is easy and safe (easy to contain, no danger of steam build up - and storing heat in water has potential for legionnaires disease). It doesn't matter to me if the system is inefficient so long as e.g half a cubic metre could store enough heat to run 3 or 4 showers per day with the cold water going through a heat exchange in the sand battery. so can anyone recommend a better storage medium - especially given that the system might have to store energy during wintery days when there is not a lot to heat it (it will be heated by solar).
Sand is a good medium because it can go up in temperature. But ,Phase Change Materials (PCM) are better, because they stay at a temperature that you desire (look on ChatGPT or tables on internet to look for the right material) while storing heat. Sand goes up in temperature if you store heat and thus also the heat loss. I would look for a PCM of about 70 to 90℃ for shower water, in the second sand video I mention a kind of mixture of two salts to choose a good temperature but look on internet.
Do you have biomass that you can use for a fire and then the exhaust gases go into a second heat exchanger in the sand, to heat it?
@@nnvasen-good-energy Thanks for your reply. As you say, sand is good because it can be heated to very high temperatures - but the problem here is that you don't really want sand at 100 degree c plus in a shower - there is going to be extreme high pressure in the pipes when not running and also the potential for someone to get in the shower and turn on boiling water. I can obviously add a thermostat to the system to prevent this - but that slightly defeats the point of using sand. I still don't understand how the temperate of salts are managed -- is it the case that if, for example, they are heated to 80 degrees c, they just keep absorbing energy which can then be released simply through running cold water through the mass in the same way you would with sand - but they will take much longer to cool down because it is not just about the inherent heat capacity of the material, it's also because they have changed phase and the temperature of the heat exchange is what determines the phase they are in? I'm not a scientist as you might gather - more a keen DIYer trying to figure the best way to do this - thanks again.
Hi Simon, I don't know if you read this after 11 days, but you are right about how Phase Change Materials (PCM) work. You have interesting ideas as a DIY, you would be a good participant of the English Facebook group, it is a bit silent there! And your comments would not be burried in the timeline of TH-cam comments, and be more visible. If you like, you can visit facebook.com/groups/1440674419825846
I think that mixing different salts to make the phase change material, results in separation after a while.
Does that happen in molten state? I will have to look up the temperatures for the single salts. I am not so fixed on this exact temperature of 140 degrees. Thank you for information us!
@@nnvasen-good-energy yes I have read that after a little use the salts may separate and thus lose the phase change. Ik wacht met interesse. Mischien zal het een goede uitslag hebben voor U.
If built with a 3x3x3meter= 27m2 sand battery which is insulated by 50cm rockwool. Used with 45 solar panels to heat while sunny, using a 6 kw rocketstove as a mass heater while no electricity, and using electricity while low price. Would this work in Norway in a passive house with 130 sqm? What if I were to replace the sand with water? What about using a heatpump to heat the sand/water with electricity?
Hi Kay, yes that should work. For each m3 sand and temperature of 400℃ above room temperature you should have 100 kWh of heat. I find it very nice to make a hybrid sand battery and such a big one! Now you have 2700 kWh and if your home needs 13 kW (cold country like Norway) of heating in steady state (comfort temperature already reached) than you have 200 hours. If I remember well, then filling the gaps between the sand grains with water will increase its heat capacity by 50 - 100% but its max temp becomes 100℃. I would instead put the heat pump in another system like in my last video 68 and enjoy the very high heat capacity of water, over 4x that of sand. It is also better because fire and electric resistors go very high in temperature (sand) and heat pumps are very limited (good for water). You will have two systems for different temperatures. People will envy you!
Thank you ❤
if your time allows, maybe a material about gravity batteries? I would like to build one. I have the opportunity.
Great suggestion! I am also fascinated. However, you need really tons of weight to have a bit of energy. I was visiting Energy Vault in Switzerland, they do it at large scale. Anyway, would like to do something. Like grandfathers clockwork!
@@nnvasen-good-energy ok and thank you for answer. My data is gen : 1000w weight : 1.6 ton height 16.8 m . it is an old fountain
That sounds good, with mgh = 272 kJ, but in a kWh there are 3600 kJ!
i am enjoying tour videos and experiments. But i would like to seethe heating of the battery using renewables, specifically Solar electric.
You can see that in especially in the previous video 66 (th-cam.com/video/d5zn3u5-ypQ/w-d-xo.html) where you see the small sand battery under a single PV panel of 100 W. Also in this video th-cam.com/video/57ZLgErL_Io/w-d-xo.html you see that it is heated with PV energy, because there is at some point beyond 7:40 minute a display that shows how much is going from the 6 kW PV into the batteries and the whole household.
Thank you anyway for your appreciation! If you like to see other themes, tell it me.
@@nnvasen-good-energy Thank you. keep up the good work.
You're wasting your time using sand, unless you can rapidly heat it above 300°C. You are able to store more sensible heat energy (40°C+) in 1kg of water than in 1kg of sand.
The specific heat capacity of water is 4.18kJ/kg/K whereas sand has a specific heat capacity of 0.835kJ/kg/K. So 1kg of water heated to 90°C would release 209kJ of heat energy before it reached 40°C. To do the same with 1kg of sand, the temperature would need to be increased to 300°C before it was able to release the same amount of energy before it reached 40°C.
You are right, it was what I replied on another comment on that same question. I even told that 350 or 400 degrees is the break even point. The advantage of sand is when you need the high temperature during consumption.
You are obviously right - but sand have three points for it: 1) it can go even higher than 600C 2) its density is higher than water by 3~4 times, so the thermal mass would be much more compact... So in qubick meter you can store significantly more energy in sand than in water (going high with temperature) and 3) it will not explode on overheating (which is also difficult with sand, but you can easily boil water - so you need to have additional safety circuits/devices).
@@dempseypoland Sand has a ~50% greater density than that of water. A simple Google search would have told you that. The issue with heating sand to such high temperatures is that unless you can do that rapidly, you lose large amounts of energy to the environment. It's simply not possible to heat sand to those high temperatures quickly enough in a domestic setting using electricity.
I partially agree with the available electrical energy to heat the sand. The sand will continue to get hotter as long as this electric power is (much) bigger than the loss. The loss can be calculated with given temperature difference and insulation parameters. Moreover, this video proposes to pick up the heat loss at the outside and consume it. In that case you don't even mind so much when heat is leaving the storage (the former "loss" ) but just that the available electric power is bigger that than what leaves the storage.
@@nnvasen-good-energy
Have you tried pool filter sand which is pure silica sand? It has a much higher thermal conductivity.
I’m testing a large 6ftx8ftx2.5ft under a greenhouse. I also mixed granite stone with the sand. I haven’t fully tested how hot it can get but I did get it up to 108°f and dropped to 79.9°f after 3 days of no additional heating.
Chat GPT is very unreliable., got some heat loss calculation that must have been out by a factor of 1000
Hi Veronica, yes, I saw it in the comment below of Sytonic. I couldn't believe it.
I saw your video about the dead wasps, amazing how it could happen. In which country are you?
@@nnvasen-good-energy hi I'm in the UK, Wales5
I thought so, that you were in Europe, because of the European Juggling convention. I hope you like the channel, if you like to see treated a theme, just tell me. Greetings from Sicily.
It doesn't do math. It is predicting the words, not doing a calculation.
This entire practice isn't going to work. The more you recover the heat from those channels, the faster the heat will be lost through the bricks. The math just doesn't work out on any of these things.
The most advantageous option is storing heated water in a dewar flask.
Hi Dus, I agree with the dewar flask (where we keep warm the coffee) principle but who will make this for us? You can use a refrigerant vacuum pump (I have it) but you need the double wall, leak free.
I agree also that the heat will come faster through the wall as you suck it away and use it, but much less will go away through the second wall (the outer wall). Only this latter leakage can be called "loss".