I started my interest in peltiers only yesterday and i learned that stacking works properly using different voltages on the stack. Thank you for unknowingly proving that .
Thank you for running this experiment! Hearing that you are interested in efficiency, are you aware that we receive power from the peltier when there is a temperature difference between the 2 sides? What about keeping the cascade setup that you have now, but instead of putting in current into the top peltier, we see how much power we can extract from the top peltier? For the top peltier, the temperature of the top side is ambient temperature and the temperature of the bottom side is the top side of the bottom peltier, which should be hot since you are running current through it to cool off the heat sink. You should be able to increase the overall efficiency of the entire system. It would be interesting to know if this would work or not. I would greatly appreciate it if you could run that experiment. Thanks.
Yes, that is called the Seebeck effect. I have been wanting to play with Thermoelectric Generators using that phenomonen for a while. Just haven't had the time. Unfortunately, I no longer have this cascaded setup. But I can try to test it in the future for sure!
@@LDSreliance if you are still interested in TECs, please let this pique your interest. what if you could run a TEC fridge in your car off of like 20 TEC placed strategically on your muffler or similar! you'd want them wired parallel, with current more important than voltage. add a converter to make it usable
@@willcal2738 you'd want to use TEGs on the muffler part as those are meant to generate electricity. I've been thinking of trying something like this out but using the cars radiator.
The major problem I noticed in these videos is the management of the heat itself. Heat sink and insulation are the key words. You are basically running 72 Watts through the first TEC so if you get a radiator from a car or an Air Conditioner unit from a scrap yard you could add 20 watt from a table fan and water pump and get a lower temp with way more efficiency instead of the (9.5 x 12) 114 Watts by stacking 2 TEC.
I'd be keen to space the cascade with a sandwich plate, 'semi' heatsink (as the cascade device is not directly loaded and each share an added value of safety from a serious breach that can occur during operation. I hear that these things can stall on start up if the opposition of dissipation is too high). The values of different peltier operation characteristics can better sympathise as one configuration might be premium to lower current operation or to the needs of higher demand such as on group for body operation and another group for a freezer unit. Then use 'the semi-stack' to improve the heat dissipation from a small group of primary stage sinks. Basically ramp up the the top deck current while boosting the primary array, overall it could be a more linier change with the compensations made by a programmed triggering network of PWM controllers. It will save on space and the extra cost of heatsink material. It can even eliminate the need for water cooling which could be a payoff for the ecconomics of a project for years to come. Then again the water thermo distribution could work as a payoff in itself. I just don't want to buy a conventional fridge or putty up an ugly old styrofoam box. You got it neat and exceptionally organised, nice to see the effort in effect! Grats on the video ✌
This is not a really good model of cascading. Generally, when you cascade, the situation involves a small yet very hot chip, & the appropriate size Peltier cannot provide enough cooling. So, the first small Peltier with a modest heatsink is applied, then a larger Peltier and heatsink attached on top of the first heatsink. Sometimes third & even 4th layers are applied. This allows greater cooling, with less risk of condensation, because any bottom area of the Peltier not in direct contact with the hot chip is ineffective, and risks condensation. Also as a way to cool when the target is crowded by other components which would prevent an oversized Peltier, even if you were able to prevent condensation.
I was able to get 250ish mV by rubbing it, with the otherside on a cold counter. seems it shot up but then would go down as something seemed to equalize, no matter how much more rubbing i did the mv wouldnt go up. Not very intuiative. It seemed to like the temperature differenace more then just heat. Another thing was rubbing the other side prodced a negative voltage, you can make AC current with this? Hot and cold type of engine, instead of stwitching polarities to drive a eletric motor, you switch temperatures to drive a peltier motor hehe, probaly at terrible efficiency though.
@@mikejones-vd3fg When you supply electricity, you generate a temperature differential. When you supply a temperature differential, you generate electricity.
Have you tried limiting the current to each junction? I would EXPECT, slowing down the cooling rate but keeping the power consumption constant should increase efficiency.
I have tested a similar setup, except using water cooling - results below: Maximum water temperature in the LQS was 35C at max load. Due to the heat distribution in the water, hot-side thermal conditions were therefore considered to be fairly static. this was monitored during the experiment. I used water as the thermal conductor between the two peltier stages - this allowed me to know if the junction between the two where above or below freezing (the two units would be frozen together if below freezing). Single peltier cooling allowed -18C to -22C at 12 volts. Cascade cooling, with both units operating at 12volts in open air gave -22C to -26C at the cold side. note the junction between the stages was above freezing cascade cooling with the 1st stage at 12 Volts and 2nd stage at 5 Volts gave -33C to -35C at the cold side note the junction between the stages was below freezing The issue here is the heat dissipation at the cold side of the junction in the cascade setup. This did not allow for delta temperatures to be obtained. My next experiment will involve two 1st stage peltiers with a copper conductor to aid heat dissipation for the 2nd stage to the 1st stage cooling. This should increase thermal dissipation at the cascade junction by up to 80% (expected deviation due to unueven heat dissipation and thermal conductivity at the copper junction).
It would be interesting to see the impact of cascading when using a peltier to heat. I would venture to guess that it would close to double the performance as peltiers are better heaters than they are coolers.
@@LDSreliance the thing is, even without the peltier effect, the peltier is a resistive element generating resistive heat. The catch is can they out preform the efficiency of a traditional resistive heater. My intuition says no due to increased thermal losses
I'm also playing with Peltiers, with a fermentation refrigerator. I've got two different cooling plates: One is a quad-set of 12706 chips arranged on 80x80mm water cooling plates, and the other is a single 12715 chip on a pair of 40x40mm plates. Both perform almost identically. My next experiment is to cascade/sandwich a 12715 and a 12706 together. the 706 will cool the cold water circuit that chills the fridge, and the 715 will take all the heat from the 706 and pipe it to a large radiator array. My thoughts are, this will lower the ambient starting point for the temp differential that the 706 experiences, since the "hot" side of the 706 will be slightly below ambient. Right now, my "hot" circuit is around 90 degrees F and my cold circuit is cooling the box to around 54 F, with ambient at 78 degrees. Reason: The 706 moves about 50 watts of heat, but produces an additional 70 watts for a total of 120 watts. Stacking multiple 706's will eventually cook your stack of them. The 715 moves about 140 watts of heat, but produces another 180 watts of heat. So, cooling a 706 with a 715 will give a thermal advantage to the hot side of the 706 and lower the starting point of the deltaT spread.
That makes a lot of sense. This was my first cascading experiment and I am not an engineer so I guess I didn't fully understand how this was going to work. I was told to try it but never told how to do it.
Hi Kelly, i'm interested to know if you did a fermentation refrigerator ? Is it working ? I'm making my beer and i'm thinking to build a fermentation refrigerator (without buy an old fridge / i don't have space for that) with peltier mods but as u can imagine, on internet, we see a lot of things (it's not working or it's perfect). So, if i can have your feedback, it will be well appreciated. Thx ! Romain ps : sorry for my english (I'm french).
Hi, Romain. I have built one and it's been through multiple iterations of peltier configs. The most successful one this far has been a pair of 12710 chips, each 40mm x 40mm, sandwiched between two 40x80mm aluminum water cooling plates. The hot circuit has two 120mm x 360mm radiators providing a total of six 120x120mm fans. This setup has been able to provide cold-crash functionality to my brew fridge, down to about 40 degrees. It would pull around 250-260 watts when running. However, the problem I have run into is that the inexpensive TEC chips available on Amazon have insufficiently sized lead wires. I have actually experienced excessive draw and wire melting. I used 10 amp automotive fuses feeding the chips so they shouldn't have been able to pull more than 10 amps. Looking at it, I think they're using 16ga stranded leads, which is really only good for 7 amps or so. It might be 14ga, definitely not 12ga. I have not yet tried a cascaded setup. But I will not buy any more cheap TECs off of Amazon that draw more than 6 amps, so I will need to source a higher quality 10-15 amp TEC chip for testing that has 12ga leads.
Great ! You're amazing to keep searching to develop a solution ! I'm not a tech' guy ! For my beer, i will simply use a old fridge and buy a device to control the temperature. But TEC was interesting for the noise and to optimize space at my appartement. But, you know, before to go to this lead, i would like to explore others alternatives. But, you did some thing which WORKS ! But it's out of my league I thinks... I imagine you spend a lot of time and you have a good insulation of your "fridge". In a nutshell, bravo ! and congrats for your work ! On RUclips, a think you''re the first to attempt a functional fridge ! Others videos was only failure ! So, you did it ! And you seem to be a great engineer ! Thx for your time ! (sorry again for my english)
What's your temperature target? My target was 4 degrees C for short term cold crashes of 24-48 hours, and sustained long term fermentation in the 15-20 degree C range. I found that pretty easily attainable once I went to water cooling and radiators for the waste heat from the TEC. A pair of 12706 chips, working in tandem to cool two 40x80mm water heat sinks, one for the hot cycle and one for the refrigeration cycle, with the cold passed to the interior of an insulated box and to a radiator with fan that circulates the internal air across the refrigeration device, will work just fine. The 12706's will give you a 18 degree C fermentation environment with no problem, but they won't be able to cold crash to near zero C. Get a power supply that can provide 200 watts at 12v. A 12v DC thermostat controller. Two 12706 TECs. Two 40mmx80mm water heat sinks. A couple of low volume water pumps, aquarium style or CPU cooling style. A 12v relay that can handle 20-30 amps (SPST relay, automotive). A pair of 120mm x 120mm fans, and a pair of 120mm x 120mm radiators. Then build a box to fit your fermentation vessel. Mine is about 1 meter tall, 75cm x 75cm in footprint, and has about 4cm of styrofoam insulation. Tall enough to fit a 25 liter fermentation bucket with airlock. Fridges have compressors in them, and the manufacturers tend to put the hump of the compressor on the bottom. This makes it hard to fit a good sized fermentation bucket inside, without buying a full size fridge. Your post has reminded me to try the cascade approach, so I have some equipment inbound to give it a try. I'll be taking a 12715 (or a 12710, not sure if I have a functional 12715 in the parts bin) as the hot-side, and a 12706 as the cold-side, stacking them, and seeing if I can hit the same 4 degrees C target as the pair of 12710's working in tandem horizontally across the same heat sinks can provide. All my TECs I have right now are low quality Amazon ones, so I won't leave it running for an extended period of time, but if it works well I will find someone who makes a quality 10-15 amp 12v TEC with larger gauge leads on it.
I believe there would be a big difference in reaching 31F vs 38F, since latent heat of fusion would be involved in reaching 31F which is much larger than sensible heat difference. So basing efficiency off of temperature alone won't give accurate results when there is phase change.
Perhaps, but that doesn't matter. I was testing real world results. I don't care what thermodynamics is happening here, I just want to know if it is better or worse than using a single TEC. Also whether it is more efficient or less efficient as far as energy used for a given temp result.
I have gotten a single peltier module down to about -40 degrees Celsius. I used a heat sink submerged in a water bath full of ice. The water bath was around 5-9 degrees Celsius. Also I got a cascade peltier system like yours down to about -15 Celsius. Pretty cool (pun intended).
Are there some peltiers that just pretty much suck in quality whereas others don't? Maybe a rhetorical question but quite new to this. I used a TEC1-12705 in a wine cooling fridge (Haier) & now the temp runs around 70 - 75 degrees F. Before it was running @ around 50 - 55 F so wondering if it would be a good idea to take it apart & sandwich another TEC1-12705 to knock it down a few more degrees? Not really worried about effieiency @ this point.. just want it to work.
Some of them are very cheaply made and have really bad quality control. The tolerances are wide. I always buy at least 2 at a time and pick the best one. They also get damaged in shipping easily. Can you measure the current it pulls?
LDSreliance Going to look @ it when I get it back on the bench. I did get 5 shipped last order so hopefully 2 of them are good enough to get a decent reading.
In the same 5 pack of 12705's I have had 2 of them measure ~ 5 Amps, two ~ 4, one ~3, and one DOA. I guess that is what you get for $15 with free shipping.
I believe if you separate two cell into two different temperature region in the house like the roof and floor then connect them together like a loop with positive goes into positive of load like fan or light or air-conditioner then go to the other side of cell on cool foundation then when sun raise it drive referigerator and charge battery but it need more cells in parale and series together to make it power refrrigerator and microwave and stove
When "Cascading" each stage should be 4 times larger .... One "coldest" with an aluminum spacer/spreader to four more arranged in a square terminated to the main heat sink. I would wire them in series with a constant current regulated power supply.
Wow. Then the applications where you would use this would be limited to ones where you need a few degrees colder and don't care about energy consumption at all. I can't imagine any scenarios but I am sure they exist.
Cascade/series yeah. It takes two modules to carry the heat of one. Place two on large hotside sink ,cut 1/4 inch or better plate of aluminium to match size of the two ,place one on top of that ,place 1/2 inch or better riser cut to size of one, place cold sink on riser ,use only two screws/clamps to sqeeze together , insulate with foam. Run peltier devices electricaly in series. Nice 50 watt cooling using 12v 150w devices. Fans Yeah.
Tired with the tec1-12703 was able to get from 71-65 deg with the same amount of power and at 80 degrees ambient temperature it makes the module almost twice as efficient.
Thank you for doing an experiment that I had wanted to see done for sometime. If you don't mind, I'd like to suggest a counterintuitive experiment; what if you put the two cold sides back to back, with two large heat sinks on the hot sides? Would the juncture where the cool sides meet be much colder than your original cascading configuration? I understand my suggestion means that the surface area of the colds sides are unavailable, but an element could be placed between them (such as copper tubes filled with alcohol), that could be chilled to use for cooling purposes. Please let me know if you think back to back cooling elements would increase the cooling effect more; thank you! And thanks for the videos....
That is an interesting thought experiment. I am not a physics expert but I don't know of a physics reason why putting two cold sides together would make each more effective. The key to making peltiers more effective is shedding heat on the hot side. But maybe someone with more experience than me can answer this for you.
No. Things only cool off when heat is removed. Heat can only be removed via a temperature differential. If each cold side reaches the same temperature, they have zero temperature differential and cannot cool each other off anymore. Thus, the temp of the cool sides will stay the same if you press them together. Whatever they are trying to cool (if there is something in between the two cool sides) will approach the cool sides' temperature faster if they are both connected, but it will not get any colder than the cool sides' temperature. The reason cascading works is that you use one TEC to get an initial temperature differential and another to get an even larger temperature differential. When the TEC's are brought together hot side to cool side, they pump heat in the same direction.
to keep the usage down you can add a flat water block to introduce water cooling the heat sink would be stage one cooling and the water circulation would be stage 2 cooling. Im currently experimenting with this to see the lowest temp i can get with a 12715 the more TDP i add to colder the cold side gets but have not managed to get higher than 10 volts for the peak cold at -4c using baby oil yep baby oil.
We should compare notes on your experiments. I am racing to do as much solar stuff as I can before fall begins and then I am going to turn my attention to indoor projects such as this peltier stuff. I want to explore TEGs and build a peltier fridge version 3.0. I also have a device to start experimenting with peltier air conditioning.
ive done alot in my days that involved TDP and the pelts can not be skimped on for the hot side thats for sure. The Tall heatsinks offer great TDP but not an option for me like you what i have is fridge related 10 cubic foot. Your H60s are doing a great job im sure but the hot side well if you do a custom liquid set up do hot side pelt to flat water block then a heat sink. One of those Arctic heat sinks with fan to the water block and get the liquid cooling active it will not only cool the water block but the heat sink as well. The concept is stage one cooling heat from the pelt saturates the water block the heat sink with the fan will pull it away and the (stage 2) excess heat gets absorbed by the liquid cooler and if you have a metal surface to mount the heat sink to (thermal tape and 2 screws to secure it) that would be even better but insulating would be vital to keep the heat out of the cold cause the metal surface is going to pull heat as well. I did something similar to this and seen a 12c temp drop with the pelt cold side and was able to increase the voltage from 9.5 at its coldest to 10.5 at its coldest on a temporary set up and i dont want the full 12 volts to extend the life of the pelt. Ive seen several pelt videos from factory built pelt fridges failing to cool due to peltier failure. Next step for me is buy an extra water cooling set up AIO or maybe custom for the cold side and Arctic bond it all together no hardware to even have a chance to cross heat over to cold that way. Well at least until the pelt is cut off but that can be worked around to so that its not so bad. From the videos ive seen you do you have enough to make 2 cold sides for one project with your AIO coolers (if you have not put them to other use) but make sure the cold side stays in the cold. Im going with custom liquid cooling/chill with mineral oil its what i know and honestly mineral oil is thinner than water non-toxic non-conductive non-corrosive. After seeing some of the AIO cooling systems fail videos cause they dry out im not sure i want to use them one small part for custom is much cheaper then a whole unit and have spare parts left over to rot away in the closet. As far as the pelt though arctic bond will release but it takes a whole lot of pressure to make it release and then the special cleaner to remove it. I can see the most common fails in a pelt fridge thats well built (listed in order) power supply (only if its under rated or barely enough), fans, pumps then the pelt last if its not over driven but first if it is. Peltier 12715 will use 8 DC amps constant and surge 10 -12 amps at 10.5 volts Not bashing at all dude just trying to help Ide like to see frost on the radiator instead of condensation with the last fridge build you attempted i think that would be exciting!
I stand corrected its not a 10 cubic foot fridge its a 4.3 cubic foot fridge with freezer i just got it from my dad today and a perfect flat metal backing this is going to be fun
Oh btw, pelteir modules dont like bangbang controllers. Filtered PWM power with thermistor sensor/control because devices are thermally conductive when off, thus losing the gain when on.
What about a PWM with a D.C. bias, so the Peltier Effect device is not switched off completely, but remains partially on whilst avoiding becoming conductive. Also phase the PWM wave, so each cascaded Peltier Effect device is activated one at a time? Would this provide good enough cooling whilst improving power consumption efficiency? Would the efficiency depend on the duty cycle of the PWM wave?
@@neilruedlinger4851 Ideally we want the same difference of temperature across each device. And to simplify the circuit as much as possible. Keep in mind, its the amperage through the device that pumps the temp. difference and temp diff moderates the resistance of them. A filter for PWM has a shcottky diode or suitable high speed rectifier, a coil (inductor) and perhaps a capacitor, depending on doody cycle. Diode clamps the flyback current to one of the rails and the coil keeps the amps relatively steady, cap enhances coil. IDK if yur pwm already has output filtering. Pelteirs seem to be more efficient at half or less than rated voltage/ amperage. Use more split the power? One I use for beer(burrhp) has a little fan on the cold sink and the thermistor just keeps it from icing up(single 50w/12v pelteir) usually settles to 4 to 6 volt undisturbed.
a mistake: this tyoe of thermometer have a 30-40 degrees angle of measurement, so if you measure at 25 cm like at the end, you'll measure also some heat from the heatsink
That is common in my experience. When I order these I always order several of them because some will arrive defective. If I order 5, hopefully at least 3 will be fully functional. But I have some that arrive completely dead and unusable and some will come like yours and never draw full power.
I am sure you could but each TEC creates more heat than cooling. So the net effect of having a whole bunch of these would be that you would generate a lot of heat and the last TEC in the chain would not cool much, if at all.
I have a mini fridge with 2 compartments. Each have own peltier with internal and external heatsink with fans. BUT shared power supply. My 2 question is : 1, Increase cold side - do I need different watt peltier or bigger hot side heatsink ? 2, separate power supply for each peltier? Thanks everyone who answers 👍👍👍
Yes, I would replace the peltier with a higher watt unit, upgrade the hot side heat sink, and add a second power supply (because the higher wattage peltier will require more power).
If it was humid and you ran it for hours then yes. If you run it indoors there will be a lot less humidity because your air conditioner will already be pulling out a bunch of the humidity.
I am telling you that I have never had any condensation problems or heard of anyone having problems. But theoretically it is possible in certain conditions.
I believe you are making a mistake by suppling the same amount of power towards te 2 peltier units. the top one should be powered at least only 40 % in order to obtain an" acceptance level of heat" able to be absorbed by the lower one . Try and it works MUCH better ..
I will try that. At least a dozen people have told me that since I posted this video. However, it does further drive home the point that cascading is EXTREMELY inefficient and you would only ever consider doing so if you had to squeeze out that extra 5 degrees at all costs.
@@mikeybaloney6211 just give it less power. If the top one is at 12v, then 40% of 12v would be about 4-5v (4.8v technically). This value should be adjusted in your finished device through trial and error to find the best temperature difference. I usually use two smps modules, they can be found really cheap on eBay or AliExpress and have adjustable voltage and often current limiting adjustments, and hooking up one to each cooler allows you to fine tune each one. Keep in mind you'll need a much larger heat sink with two of them than with one. I've seen most people use water cooling when stacking them actually so that's something worth looking into, searching "water blocks" on eBay can get you some good info, and some research into over clocking forums will give you an idea of how to set it all up. What kind of application are you planning on using these coolers with?
i think you.. need a larger and a smaller module. i mean say.. a 100 watt peltier will heat its hot side with 100 watt + the heat it moved, so the 2nd stage cascaded should be able to move that amount. and your heatsink should be able to keep the top of the casacde within reasonable temps, so dissipate like 300 watts.
Just using the heat prodused from the teromo ac cop eficent proses. I think it vil work to reduse power to heatpump and ac to near serro. Null. Nothing.
sort of. the first layer would make the majority of the energy, the next layer would only make a fraction of that, and the next a fraction of that. but it would never go over 100% efficiency if that's what you're hoping, but theoretically, with perfect insulation, you could get closer and closer to 100.
Just for your reference in the future, its not good to spread the thermal compound on the peltier like that, especially with your finger. Anyway, great video :D
Haha, I knew while I was doing it that I was going to get some comments about that. If this was a permanent installation I certainly would have done a few things differently and like I said in the video I am sure I could have squeezed out a few more degrees out of the cascaded setup. I hope people get the point, though.
hello LDSreliance! can you try this idea? heres my idea or more likely arrange the components like this. Heat sink with fan, (hot side)Peltier(cold side),aluminum water block, (cold side)Peltier(hot side), heat sink with fan now im interested if we can use the cooled water inside the block for some interesting projects like pump it into radiators making like a crazy diy airconditioner. and maybe powered by solar panels :D
Yes that would work great. You could use a high powered pump to move water through the block quickly with a setup like that since it is being cooled on both sides. However, keep in mind that peltiers are very energy inefficient so using two peltiers at all times like that will use more power for a given amount of cooling than a traditional air conditioner.
geothermal supposedly can be used with graphene woven cables put not too many kilometers into the earths crust to obtain much heat. Or simply to heat water and turn an electric turbine and afford more planetary harmony. Maybe much better than fission. billionsinchange.org was working on it. Thanks. Remarkable play time and research with peltier modules in series. I like.
They work both ways. When you see teg it just means the same peltier effect is being used but the quality of materials is meant for heat stress. Tec module have smaller elements and less robust wiring and the ceramic surface can be damaged by higher temp on hot side
maybe a better validation would be to say cooling something. Like say running current in some mossfet chips on a heat sink and repeat test to see what setup cools the mossfets most efficient and also see how doing the TEC in parallel and series configuration. or send me the stuff and I will run the test LOL. Sorry I worked at a factory where I was used by the engineers that mid 6 figure to make their ideas work in the real 🌎
To increase efficiency, it would be much better to not fix the peltier modules to each other but to have them separate, with individual heat sinks for each peltier device. My ideal construction would be like a minifridge within a minifridge. I think this way, one would achieve much greater efficiency. >
I used these for scientific instrumentation this wont work you need to have proper multiple stacks or stacks where the coolers decrease in size as they need to dissipate the heat
I want to make a cooling system that uses 12v 10 amp peltier + Pc fan that uses 12v 0.3 amp I want to buy this battery (12V 10Ah / 20 HR) how long will the battery last ? and what does (12V 10Ah / 20 HR) mean? thank you
It should last roughly 25-30 hours depending on other variables. The 10Ah rating @ 20 hours means that they tested how much power the battery could produce for 20 hours. 20 x ___ = 10 is the formula to figure out how many amps it took. So in this case that battery will produce 0.5 amps for 20 hours.
ahmad abid Sorry, I misread your comment. I only saw the 0.3 amp fan. I would estimate that battery will power the peltier plus fan for less than 1 hour.
ahmad abid I did not calculate that number. The answer is from personal experience. That battery is small and it is rated to produce a small amount of current for a long time (0.5 amps for 20 hours). When you require a lot more amps, you will get a lot less time out of the battery. My experience tells me that pulling more than 10 amps from a small battery like that you will probably get about 30 minutes, plus or minus, of run time if the battery is fully charged.
To my knowledge peltiers transfer less heat than they them selves create. Using identical elements at same power cascaded does nothing or melts the "hot side" one. You do see cascaded peltiers that have high delta T, but they have very low heat capacity. There never was any reason in the efficiency side to do this. Only thing to gain is higher delta T. Using 2 side by side with sufficient cooling would cool higher heat load, would give lower temps in short run like this.That would never get to that theoretical delta T proper cascade would have. To be honest don't know what you are testing here. Cascade did not do something that it never was meant to do in faulty configuration like this. Put 2 of those on the hot side of one and you will get lower temps faster and might be able to move enough heat from the cold peltier. In longer run times that might result in higher delta T. The system is not in any way insulated so efficiency would be horrible so might not make much difference. To sum it up. There is actual factual info and products doing this and they work in creating higher delta T. What you should freshen up on is theory and concept of how these things work at general level.
That is true. I don't know the theory behind cascading. I have been told by at least a dozen comments to my peltier videos that I would get better results by sandwiching two units together hot side to cold side. That is just not true. I get what you are saying and I am sure there are devices that use this concept but again my main point in the video is whatever marginal benefit you get from successfully cascading and increasing the delta T could be more than matched by just getting a more efficient, double power peltier module.
Yes you don't get any extra delta T doing that. If you need capability for higher delta T then cascading works. But then again your max wattage is transfered at delta T of 0 and at speced delta T at no load at all. Most times adding more capacity for wattage gives lower temperatures since people seem to cool things that have constant generation of heat. Cascading 2 same TECs is just really bad idea. You are moving from air that the colder one touches something like 65w and adding to that close the same from the TEC it self. The other TEC can only transfer 65w and cold side on that will raise. That means hot side will raise and you will have burned TEC. First the hotter one then the colder one.
You have no cooling the way you are dooing it. And the cold side tec must be half or less the power rating. First tec might transfere about 100 watt of heat on the hot side and 50 from the cold side then the next have to pull out that 100 pluss it's own 50 watt and that is way above its limits
I started my interest in peltiers only yesterday and i learned that stacking works properly using different voltages on the stack. Thank you for unknowingly proving that .
At least someone saying this!
He should get far lower temperatures if the second battery was run at abt half the voltage of the first one!
(0:36) - The hot side touching the cold side is not *_"back to back"_*
If anything, *_that_* would be *_back to front_*
_(or front to back)_
>
Thank you for running this experiment! Hearing that you are interested in efficiency, are you aware that we receive power from the peltier when there is a temperature difference between the 2 sides? What about keeping the cascade setup that you have now, but instead of putting in current into the top peltier, we see how much power we can extract from the top peltier? For the top peltier, the temperature of the top side is ambient temperature and the temperature of the bottom side is the top side of the bottom peltier, which should be hot since you are running current through it to cool off the heat sink. You should be able to increase the overall efficiency of the entire system. It would be interesting to know if this would work or not. I would greatly appreciate it if you could run that experiment. Thanks.
Yes, that is called the Seebeck effect. I have been wanting to play with Thermoelectric Generators using that phenomonen for a while. Just haven't had the time. Unfortunately, I no longer have this cascaded setup. But I can try to test it in the future for sure!
@@LDSreliance if you are still interested in TECs, please let this pique your interest. what if you could run a TEC fridge in your car off of like 20 TEC placed strategically on your muffler or similar! you'd want them wired parallel, with current more important than voltage. add a converter to make it usable
@@willcal2738 you'd want to use TEGs on the muffler part as those are meant to generate electricity. I've been thinking of trying something like this out but using the cars radiator.
The major problem I noticed in these videos is the management of the heat itself.
Heat sink and insulation are the key words.
You are basically running 72 Watts through the first TEC so if you get a radiator from a car or an Air Conditioner unit from a scrap yard you could add 20 watt from a table fan and water pump and get a lower temp with way more efficiency instead of the (9.5 x 12) 114 Watts by stacking 2 TEC.
I'd be keen to space the cascade with a sandwich plate, 'semi' heatsink (as the cascade device is not directly loaded and each share an added value of safety from a serious breach that can occur during operation. I hear that these things can stall on start up if the opposition of dissipation is too high). The values of different peltier operation characteristics can better sympathise as one configuration might be premium to lower current operation or to the needs of higher demand such as on group for body operation and another group for a freezer unit.
Then use 'the semi-stack' to improve the heat dissipation from a small group of primary stage sinks.
Basically ramp up the the top deck current while boosting the primary array, overall it could be a more linier change with the compensations made by a programmed triggering network of PWM controllers.
It will save on space and the extra cost of heatsink material. It can even eliminate the need for water cooling which could be a payoff for the ecconomics of a project for years to come. Then again the water thermo distribution could work as a payoff in itself.
I just don't want to buy a conventional fridge or putty up an ugly old styrofoam box.
You got it neat and exceptionally organised, nice to see the effort in effect!
Grats on the video ✌
This is not a really good model of cascading. Generally, when you cascade, the situation involves a small yet very hot chip, & the appropriate size Peltier cannot provide enough cooling. So, the first small Peltier with a modest heatsink is applied, then a larger Peltier and heatsink attached on top of the first heatsink. Sometimes third & even 4th layers are applied. This allows greater cooling, with less risk of condensation, because any bottom area of the Peltier not in direct contact with the hot chip is ineffective, and risks condensation. Also as a way to cool when the target is crowded by other components which would prevent an oversized Peltier, even if you were able to prevent condensation.
Great video, would be great to see how it goes generating power instead of heating and cooling.
I was able to get 250ish mV by rubbing it, with the otherside on a cold counter. seems it shot up but then would go down as something seemed to equalize, no matter how much more rubbing i did the mv wouldnt go up. Not very intuiative. It seemed to like the temperature differenace more then just heat. Another thing was rubbing the other side prodced a negative voltage, you can make AC current with this? Hot and cold type of engine, instead of stwitching polarities to drive a eletric motor, you switch temperatures to drive a peltier motor hehe, probaly at terrible efficiency though.
@@mikejones-vd3fg When you supply electricity, you generate a temperature differential. When you supply a temperature differential, you generate electricity.
Have you tried limiting the current to each junction? I would EXPECT, slowing down the cooling rate but keeping the power consumption constant should increase efficiency.
I have tested a similar setup, except using water cooling - results below:
Maximum water temperature in the LQS was 35C at max load. Due to the heat distribution in the water, hot-side thermal conditions were therefore considered to be fairly static. this was monitored during the experiment.
I used water as the thermal conductor between the two peltier stages - this allowed me to know if the junction between the two where above or below freezing (the two units would be frozen together if below freezing).
Single peltier cooling allowed -18C to -22C at 12 volts.
Cascade cooling, with both units operating at 12volts in open air gave -22C to -26C at the cold side.
note the junction between the stages was above freezing
cascade cooling with the 1st stage at 12 Volts and 2nd stage at 5 Volts gave -33C to -35C at the cold side
note the junction between the stages was below freezing
The issue here is the heat dissipation at the cold side of the junction in the cascade setup. This did not allow for delta temperatures to be obtained. My next experiment will involve two 1st stage peltiers with a copper conductor to aid heat dissipation for the 2nd stage to the 1st stage cooling. This should increase thermal dissipation at the cascade junction by up to 80% (expected deviation due to unueven heat dissipation and thermal conductivity at the copper junction).
Nice info. When I did this test I was not aware that the second peltier module needed to be stronger than the first. I will test that someday.
It would be interesting to see the impact of cascading when using a peltier to heat. I would venture to guess that it would close to double the performance as peltiers are better heaters than they are coolers.
It would definitely increase performance. I don't think it would be double but it also wouldn't surprise me.
@@LDSreliance the thing is, even without the peltier effect, the peltier is a resistive element generating resistive heat. The catch is can they out preform the efficiency of a traditional resistive heater. My intuition says no due to increased thermal losses
True. And they do require a much bigger heat sink on the hot side.
I'm also playing with Peltiers, with a fermentation refrigerator.
I've got two different cooling plates: One is a quad-set of 12706 chips arranged on 80x80mm water cooling plates, and the other is a single 12715 chip on a pair of 40x40mm plates. Both perform almost identically.
My next experiment is to cascade/sandwich a 12715 and a 12706 together. the 706 will cool the cold water circuit that chills the fridge, and the 715 will take all the heat from the 706 and pipe it to a large radiator array.
My thoughts are, this will lower the ambient starting point for the temp differential that the 706 experiences, since the "hot" side of the 706 will be slightly below ambient. Right now, my "hot" circuit is around 90 degrees F and my cold circuit is cooling the box to around 54 F, with ambient at 78 degrees.
Reason: The 706 moves about 50 watts of heat, but produces an additional 70 watts for a total of 120 watts. Stacking multiple 706's will eventually cook your stack of them. The 715 moves about 140 watts of heat, but produces another 180 watts of heat. So, cooling a 706 with a 715 will give a thermal advantage to the hot side of the 706 and lower the starting point of the deltaT spread.
That makes a lot of sense. This was my first cascading experiment and I am not an engineer so I guess I didn't fully understand how this was going to work. I was told to try it but never told how to do it.
Hi Kelly, i'm interested to know if you did a fermentation refrigerator ? Is it working ? I'm making my beer and i'm thinking to build a fermentation refrigerator (without buy an old fridge / i don't have space for that) with peltier mods but as u can imagine, on internet, we see a lot of things (it's not working or it's perfect). So, if i can have your feedback, it will be well appreciated.
Thx !
Romain
ps : sorry for my english (I'm french).
Hi, Romain. I have built one and it's been through multiple iterations of peltier configs. The most successful one this far has been a pair of 12710 chips, each 40mm x 40mm, sandwiched between two 40x80mm aluminum water cooling plates. The hot circuit has two 120mm x 360mm radiators providing a total of six 120x120mm fans.
This setup has been able to provide cold-crash functionality to my brew fridge, down to about 40 degrees. It would pull around 250-260 watts when running.
However, the problem I have run into is that the inexpensive TEC chips available on Amazon have insufficiently sized lead wires. I have actually experienced excessive draw and wire melting. I used 10 amp automotive fuses feeding the chips so they shouldn't have been able to pull more than 10 amps. Looking at it, I think they're using 16ga stranded leads, which is really only good for 7 amps or so. It might be 14ga, definitely not 12ga.
I have not yet tried a cascaded setup. But I will not buy any more cheap TECs off of Amazon that draw more than 6 amps, so I will need to source a higher quality 10-15 amp TEC chip for testing that has 12ga leads.
Great ! You're amazing to keep searching to develop a solution ! I'm not a tech' guy ! For my beer, i will simply use a old fridge and buy a device to control the temperature. But TEC was interesting for the noise and to optimize space at my appartement. But, you know, before to go to this lead, i would like to explore others alternatives. But, you did some thing which WORKS ! But it's out of my league I thinks... I imagine you spend a lot of time and you have a good insulation of your "fridge". In a nutshell, bravo ! and congrats for your work ! On RUclips, a think you''re the first to attempt a functional fridge ! Others videos was only failure ! So, you did it ! And you seem to be a great engineer ! Thx for your time ! (sorry again for my english)
What's your temperature target?
My target was 4 degrees C for short term cold crashes of 24-48 hours, and sustained long term fermentation in the 15-20 degree C range.
I found that pretty easily attainable once I went to water cooling and radiators for the waste heat from the TEC. A pair of 12706 chips, working in tandem to cool two 40x80mm water heat sinks, one for the hot cycle and one for the refrigeration cycle, with the cold passed to the interior of an insulated box and to a radiator with fan that circulates the internal air across the refrigeration device, will work just fine. The 12706's will give you a 18 degree C fermentation environment with no problem, but they won't be able to cold crash to near zero C.
Get a power supply that can provide 200 watts at 12v. A 12v DC thermostat controller. Two 12706 TECs. Two 40mmx80mm water heat sinks. A couple of low volume water pumps, aquarium style or CPU cooling style. A 12v relay that can handle 20-30 amps (SPST relay, automotive). A pair of 120mm x 120mm fans, and a pair of 120mm x 120mm radiators.
Then build a box to fit your fermentation vessel. Mine is about 1 meter tall, 75cm x 75cm in footprint, and has about 4cm of styrofoam insulation. Tall enough to fit a 25 liter fermentation bucket with airlock.
Fridges have compressors in them, and the manufacturers tend to put the hump of the compressor on the bottom. This makes it hard to fit a good sized fermentation bucket inside, without buying a full size fridge.
Your post has reminded me to try the cascade approach, so I have some equipment inbound to give it a try. I'll be taking a 12715 (or a 12710, not sure if I have a functional 12715 in the parts bin) as the hot-side, and a 12706 as the cold-side, stacking them, and seeing if I can hit the same 4 degrees C target as the pair of 12710's working in tandem horizontally across the same heat sinks can provide.
All my TECs I have right now are low quality Amazon ones, so I won't leave it running for an extended period of time, but if it works well I will find someone who makes a quality 10-15 amp 12v TEC with larger gauge leads on it.
Great that you tested the concept, the manufacturer in China Had done that.
They have? I haven't seen any information on that.
was that thermal compound acting as an adhesive? I didn't see the test device move.
Yes, the thermal compound does form a little bit of a bond between the heatsink and the peltier (or CPU).
If you want to cascade the first stage should be more tecs covering a bigger area. That should make the cascading effect more noticeable
Very cool...learned a lot. See you are using the Uni-T clamp meter...thanks again for the review. Mine is awesome and use it quite a bit!
Yes that is one of my favorite new tools. So useful and I can't believe I went without one for so long. I had no idea what I was missing!
Górny peltier powinien być zasilany 2-3X mniejszą mocą niż dolny (dolny na radiatorze).
I believe there would be a big difference in reaching 31F vs 38F, since latent heat of fusion would be involved in reaching 31F which is much larger than sensible heat difference. So basing efficiency off of temperature alone won't give accurate results when there is phase change.
Perhaps, but that doesn't matter. I was testing real world results. I don't care what thermodynamics is happening here, I just want to know if it is better or worse than using a single TEC. Also whether it is more efficient or less efficient as far as energy used for a given temp result.
Is it best to wire the Peltier units in series? Parallel? Or Combination?
I have gotten a single peltier module down to about -40 degrees Celsius. I used a heat sink submerged in a water bath full of ice. The water bath was around 5-9 degrees Celsius. Also I got a cascade peltier system like yours down to about -15 Celsius. Pretty cool (pun intended).
Nice, that is a good idea. Nice job!
I think the problem is that you don't have enough airflow, which makes the whole system less effective. Good work, your setup isn't as messy as mine.
Maybe not. I plan on getting back to some peltier experiements this winter.
Wow, that was fast, funny enough I am writing this comment as I am working on a peltier experiment. I am getting -20 Celsius stable.
Nice. What are you using on the hot side and cold side? You should do a video response to this video and show me.
Are there some peltiers that just pretty much suck in quality whereas others don't? Maybe a rhetorical question but quite new to this. I used a TEC1-12705 in a wine cooling fridge (Haier) & now the temp runs around 70 - 75 degrees F. Before it was running @ around 50 - 55 F so wondering if it would be a good idea to take it apart & sandwich another TEC1-12705 to knock it down a few more degrees? Not really worried about effieiency @ this point.. just want it to work.
Some of them are very cheaply made and have really bad quality control. The tolerances are wide. I always buy at least 2 at a time and pick the best one. They also get damaged in shipping easily.
Can you measure the current it pulls?
LDSreliance Going to look @ it when I get it back on the bench. I did get 5 shipped last order so hopefully 2 of them are good enough to get a decent reading.
In the same 5 pack of 12705's I have had 2 of them measure ~ 5 Amps, two ~ 4, one ~3, and one DOA. I guess that is what you get for $15 with free shipping.
I believe if you separate two cell into two different temperature region in the house like the roof and floor then connect them together like a loop with positive goes into positive of load like fan or light or air-conditioner then go to the other side of cell on cool foundation then when sun raise it drive referigerator and charge battery but it need more cells in parale and series together to make it power refrrigerator and microwave and stove
When "Cascading" each stage should be 4 times larger .... One "coldest" with an aluminum spacer/spreader to four more arranged in a square terminated to the main heat sink. I would wire them in series with a constant current regulated power supply.
Wow. Then the applications where you would use this would be limited to ones where you need a few degrees colder and don't care about energy consumption at all. I can't imagine any scenarios but I am sure they exist.
Cascade/series yeah. It takes two modules to carry the heat of one. Place two on large hotside sink ,cut 1/4 inch or better plate of aluminium to match size of the two ,place one on top of that ,place 1/2 inch or better riser cut to size of one, place cold sink on riser ,use only two screws/clamps to sqeeze together , insulate with foam. Run peltier devices electricaly in series. Nice 50 watt cooling using 12v 150w devices. Fans Yeah.
Tired with the tec1-12703 was able to get from 71-65 deg with the same amount of power and at 80 degrees ambient temperature it makes the module almost twice as efficient.
Thank you for doing an experiment that I had wanted to see done for sometime. If you don't mind, I'd like to suggest a counterintuitive experiment; what if you put the two cold sides back to back, with two large heat sinks on the hot sides? Would the juncture where the cool sides meet be much colder than your original cascading configuration? I understand my suggestion means that the surface area of the colds sides are unavailable, but an element could be placed between them (such as copper tubes filled with alcohol), that could be chilled to use for cooling purposes. Please let me know if you think back to back cooling elements would increase the cooling effect more; thank you! And thanks for the videos....
That is an interesting thought experiment. I am not a physics expert but I don't know of a physics reason why putting two cold sides together would make each more effective. The key to making peltiers more effective is shedding heat on the hot side. But maybe someone with more experience than me can answer this for you.
No. Things only cool off when heat is removed. Heat can only be removed via a temperature differential. If each cold side reaches the same temperature, they have zero temperature differential and cannot cool each other off anymore.
Thus, the temp of the cool sides will stay the same if you press them together.
Whatever they are trying to cool (if there is something in between the two cool sides) will approach the cool sides' temperature faster if they are both connected, but it will not get any colder than the cool sides' temperature.
The reason cascading works is that you use one TEC to get an initial temperature differential and another to get an even larger temperature differential. When the TEC's are brought together hot side to cool side, they pump heat in the same direction.
You're saying it proper!
Pel-Tee-Yay
How many volts were sent?
Great content
Batterie Temperature Management
Thanks!
3 12706 units stacked, using 2 at 5v
and 1 at 3v. 30W. -30C
your heat sink isn't removing heat of the base Peletier.. try to replace the heat sink with a bigger one
to keep the usage down you can add a flat water block to introduce water cooling the heat sink would be stage one cooling and the water circulation would be stage 2 cooling. Im currently experimenting with this to see the lowest temp i can get with a 12715 the more TDP i add to colder the cold side gets but have not managed to get higher than 10 volts for the peak cold at -4c using baby oil yep baby oil.
We should compare notes on your experiments. I am racing to do as much solar stuff as I can before fall begins and then I am going to turn my attention to indoor projects such as this peltier stuff. I want to explore TEGs and build a peltier fridge version 3.0. I also have a device to start experimenting with peltier air conditioning.
ive done alot in my days that involved TDP and the pelts can not be skimped on for the hot side thats for sure. The Tall heatsinks offer great TDP but not an option for me like you what i have is fridge related 10 cubic foot. Your H60s are doing a great job im sure but the hot side well if you do a custom liquid set up do hot side pelt to flat water block then a heat sink. One of those Arctic heat sinks with fan to the water block and get the liquid cooling active it will not only cool the water block but the heat sink as well. The concept is stage one cooling heat from the pelt saturates the water block the heat sink with the fan will pull it away and the (stage 2) excess heat gets absorbed by the liquid cooler and if you have a metal surface to mount the heat sink to (thermal tape and 2 screws to secure it) that would be even better but insulating would be vital to keep the heat out of the cold cause the metal surface is going to pull heat as well. I did something similar to this and seen a 12c temp drop with the pelt cold side and was able to increase the voltage from 9.5 at its coldest to 10.5 at its coldest on a temporary set up and i dont want the full 12 volts to extend the life of the pelt. Ive seen several pelt videos from factory built pelt fridges failing to cool due to peltier failure. Next step for me is buy an extra water cooling set up AIO or maybe custom for the cold side and Arctic bond it all together no hardware to even have a chance to cross heat over to cold that way. Well at least until the pelt is cut off but that can be worked around to so that its not so bad. From the videos ive seen you do you have enough to make 2 cold sides for one project with your AIO coolers (if you have not put them to other use) but make sure the cold side stays in the cold. Im going with custom liquid cooling/chill with mineral oil its what i know and honestly mineral oil is thinner than water non-toxic non-conductive non-corrosive. After seeing some of the AIO cooling systems fail videos cause they dry out im not sure i want to use them one small part for custom is much cheaper then a whole unit and have spare parts left over to rot away in the closet. As far as the pelt though arctic bond will release but it takes a whole lot of pressure to make it release and then the special cleaner to remove it. I can see the most common fails in a pelt fridge thats well built (listed in order) power supply (only if its under rated or barely enough), fans, pumps then the pelt last if its not over driven but first if it is.
Peltier 12715 will use 8 DC amps constant and surge 10 -12 amps at 10.5 volts
Not bashing at all dude just trying to help Ide like to see frost on the radiator instead of condensation with the last fridge build you attempted i think that would be exciting!
Cool, I will have to give that a try. Good ideas.
I stand corrected its not a 10 cubic foot fridge its a 4.3 cubic foot fridge with freezer i just got it from my dad today and a perfect flat metal backing this is going to be fun
Sounds fun to me! I tried converting a small freezer one time to peltier from compressor and had minimal luck. So hopefully you have a better time.
Oh btw, pelteir modules dont like bangbang controllers. Filtered PWM power with thermistor sensor/control because devices are thermally conductive when off, thus losing the gain when on.
What about a PWM with a D.C. bias, so the Peltier Effect device is not switched off completely, but remains partially on whilst avoiding becoming conductive. Also phase the PWM wave, so each cascaded Peltier Effect device is activated one at a time?
Would this provide good enough cooling whilst improving power consumption efficiency? Would the efficiency depend on the duty cycle of the PWM wave?
@@neilruedlinger4851 Ideally we want the same difference of temperature across each device. And to simplify the circuit as much as possible. Keep in mind, its the amperage through the device that pumps the temp. difference and temp diff moderates the resistance of them. A filter for PWM has a shcottky diode or suitable high speed rectifier, a coil (inductor) and perhaps a capacitor, depending on doody cycle. Diode clamps the flyback current to one of the rails and the coil keeps the amps relatively steady, cap enhances coil. IDK if yur pwm already has output filtering. Pelteirs seem to be more efficient at half or less than rated voltage/ amperage. Use more split the power? One I use for beer(burrhp) has a little fan on the cold sink and the thermistor just keeps it from icing up(single 50w/12v pelteir) usually settles to 4 to 6 volt undisturbed.
a mistake: this tyoe of thermometer have a 30-40 degrees angle of measurement, so if you measure at 25 cm like at the end, you'll measure also some heat from the heatsink
Good to know.
LDSreliance In this case it wouldn't be nothing big, like 4-6 * but still someting
Yeah but it is always best to be precise if you can.
Sir, my peltier module is drawing only 2 Amps of current
What should I do ?
That is common in my experience. When I order these I always order several of them because some will arrive defective. If I order 5, hopefully at least 3 will be fully functional. But I have some that arrive completely dead and unusable and some will come like yours and never draw full power.
@@LDSreliance ohh okay
I have taught power supply problem
Could you use enough tecs to form essentially a ring cooling itself...
I am sure you could but each TEC creates more heat than cooling. So the net effect of having a whole bunch of these would be that you would generate a lot of heat and the last TEC in the chain would not cool much, if at all.
LDSreliance thanks!
You are welcome! Thanks for watching.
I have a mini fridge with 2 compartments.
Each have own peltier with internal and external heatsink with fans.
BUT shared power supply.
My 2 question is :
1, Increase cold side - do I need different watt peltier or bigger hot side heatsink ?
2, separate power supply for each peltier?
Thanks everyone who answers
👍👍👍
Yes, I would replace the peltier with a higher watt unit, upgrade the hot side heat sink, and add a second power supply (because the higher wattage peltier will require more power).
How do you avoid condensation So water does not occur ?
I have not run into a problem with condensation but then again I have not used one of these all day every day for a long period of time.
ohh okey, so if you did run it all day there will be a problem - right ?
If it was humid and you ran it for hours then yes. If you run it indoors there will be a lot less humidity because your air conditioner will already be pulling out a bunch of the humidity.
you dont no a way to not get condensation ?
I am telling you that I have never had any condensation problems or heard of anyone having problems. But theoretically it is possible in certain conditions.
I believe you are making a mistake by suppling the same amount of power towards te 2 peltier units. the top one should be powered at least only 40 % in order to obtain an" acceptance level of heat" able to be absorbed by the lower one . Try and it works MUCH better ..
I will try that. At least a dozen people have told me that since I posted this video. However, it does further drive home the point that cascading is EXTREMELY inefficient and you would only ever consider doing so if you had to squeeze out that extra 5 degrees at all costs.
"the top one should be powered at least only 40 % in order to obtain an" acceptance level of heat"
How is that done?
@@mikeybaloney6211 just give it less power. If the top one is at 12v, then 40% of 12v would be about 4-5v (4.8v technically). This value should be adjusted in your finished device through trial and error to find the best temperature difference. I usually use two smps modules, they can be found really cheap on eBay or AliExpress and have adjustable voltage and often current limiting adjustments, and hooking up one to each cooler allows you to fine tune each one. Keep in mind you'll need a much larger heat sink with two of them than with one. I've seen most people use water cooling when stacking them actually so that's something worth looking into, searching "water blocks" on eBay can get you some good info, and some research into over clocking forums will give you an idea of how to set it all up. What kind of application are you planning on using these coolers with?
i think you.. need a larger and a smaller module.
i mean say.. a 100 watt peltier will heat its hot side with 100 watt + the heat it moved, so the 2nd stage cascaded should be able to move that amount. and your heatsink should be able to keep the top of the casacde within reasonable temps, so dissipate like 300 watts.
Yep, I didn't know that when I did this test. I'll have to try that out sometime.
I dnt know how u got upto -40c. I have tried with water cooling system and i have got up to -20c max
My single12 volt Peltier gets below freezing
With no heat sink attached to the cold side? Mine too.
can we use water as a heat sink
A liquid cooler makes a great heat sink. In most cases they are superior to air heat sinks.
Can you run a heatpump ac on the cop effect from a ac heatpump? ANY BODY TRY IT?!
Just using the heat prodused from the teromo ac cop eficent proses. I think it vil work to reduse power to heatpump and ac to near serro. Null. Nothing.
Would cascading work in the reverse meaning to generate more power for a stove fan? Anybody?
sort of. the first layer would make the majority of the energy, the next layer would only make a fraction of that, and the next a fraction of that.
but it would never go over 100% efficiency if that's what you're hoping, but theoretically, with perfect insulation, you could get closer and closer to 100.
See Seebeck effect
My dear, current during operation not clear that is 0.44 or 44 amps.
Just for your reference in the future, its not good to spread the thermal compound on the peltier like that, especially with your finger. Anyway, great video :D
Haha, I knew while I was doing it that I was going to get some comments about that. If this was a permanent installation I certainly would have done a few things differently and like I said in the video I am sure I could have squeezed out a few more degrees out of the cascaded setup. I hope people get the point, though.
hello LDSreliance! can you try this idea?
heres my idea or more likely arrange the components like this.
Heat sink with fan, (hot side)Peltier(cold side),aluminum water block, (cold side)Peltier(hot side), heat sink with fan
now im interested if we can use the cooled water inside the block for some interesting projects like pump it into radiators making like a crazy diy airconditioner. and maybe powered by solar panels :D
Yes that would work great. You could use a high powered pump to move water through the block quickly with a setup like that since it is being cooled on both sides. However, keep in mind that peltiers are very energy inefficient so using two peltiers at all times like that will use more power for a given amount of cooling than a traditional air conditioner.
@@LDSreliance how much use energy power one 12706 or another or 2 peltier in AC amp?
Your heat pipes are upside down, that might help if you flipped it
Yay, more peltier!
Working on another video today that has to do with peltiers. Stay tuned!
Another peltier video today: ruclips.net/video/nflU4tiJjPI/видео.html
i thought you said put them back 2 back but you didn't you put them front to back
Teg peltier makes energy
A little. It takes a lot of heat to make any power, though.
geothermal supposedly can be used with graphene woven cables put not too many kilometers into the earths crust to obtain much heat. Or simply to heat water and turn an electric turbine and afford more planetary harmony. Maybe much better than fission. billionsinchange.org was working on it. Thanks. Remarkable play time and research with peltier modules in series. I like.
They work both ways. When you see teg it just means the same peltier effect is being used but the quality of materials is meant for heat stress. Tec module have smaller elements and less robust wiring and the ceramic surface can be damaged by higher temp on hot side
thanks for sharing. simple but great test
You are welcome. Thanks for watching!
maybe a better validation would be to say cooling something. Like say running current in some mossfet chips on a heat sink and repeat test to see what setup cools the mossfets most efficient and also see how doing the TEC in parallel and series configuration. or send me the stuff and I will run the test LOL. Sorry I worked at a factory where I was used by the engineers that mid 6 figure to make their ideas work in the real 🌎
Super!
what about cascading 10 peltiers ?
I am sure you could do it but it would consume a ton of energy. I can't think of any scenario where you would need to do that.
To increase efficiency, it would be much better to not fix the peltier modules to each other but to have them separate, with individual heat sinks for each peltier device.
My ideal construction would be like a minifridge within a minifridge.
I think this way, one would achieve much greater efficiency.
>
I used these for scientific instrumentation this wont work you need to have proper multiple stacks or stacks where the coolers decrease in size as they need to dissipate the heat
I want to make a cooling system that uses 12v 10 amp peltier + Pc fan that uses 12v 0.3 amp
I want to buy this battery (12V 10Ah / 20 HR)
how long will the battery last ?
and what does (12V 10Ah / 20 HR) mean?
thank you
It should last roughly 25-30 hours depending on other variables.
The 10Ah rating @ 20 hours means that they tested how much power the battery could produce for 20 hours. 20 x ___ = 10 is the formula to figure out how many amps it took. So in this case that battery will produce 0.5 amps for 20 hours.
i'm confused !
if it is gonna give 0.5 amp for 20 hour, what I using is taking more than 10 amps, how will it last for 25-30 hours
?
ahmad abid
Sorry, I misread your comment. I only saw the 0.3 amp fan. I would estimate that battery will power the peltier plus fan for less than 1 hour.
can you please explain how did you figure out that number, or the formula to calculate that, i didn't quit understand it
ahmad abid
I did not calculate that number. The answer is from personal experience. That battery is small and it is rated to produce a small amount of current for a long time (0.5 amps for 20 hours). When you require a lot more amps, you will get a lot less time out of the battery. My experience tells me that pulling more than 10 amps from a small battery like that you will probably get about 30 minutes, plus or minus, of run time if the battery is fully charged.
Now.. let's wire them in series and see
What happens???
To my knowledge peltiers transfer less heat than they them selves create. Using identical elements at same power cascaded does nothing or melts the "hot side" one. You do see cascaded peltiers that have high delta T, but they have very low heat capacity. There never was any reason in the efficiency side to do this. Only thing to gain is higher delta T. Using 2 side by side with sufficient cooling would cool higher heat load, would give lower temps in short run like this.That would never get to that theoretical delta T proper cascade would have. To be honest don't know what you are testing here. Cascade did not do something that it never was meant to do in faulty configuration like this. Put 2 of those on the hot side of one and you will get lower temps faster and might be able to move enough heat from the cold peltier. In longer run times that might result in higher delta T. The system is not in any way insulated so efficiency would be horrible so might not make much difference. To sum it up. There is actual factual info and products doing this and they work in creating higher delta T. What you should freshen up on is theory and concept of how these things work at general level.
That is true. I don't know the theory behind cascading. I have been told by at least a dozen comments to my peltier videos that I would get better results by sandwiching two units together hot side to cold side. That is just not true.
I get what you are saying and I am sure there are devices that use this concept but again my main point in the video is whatever marginal benefit you get from successfully cascading and increasing the delta T could be more than matched by just getting a more efficient, double power peltier module.
Yes you don't get any extra delta T doing that. If you need capability for higher delta T then cascading works. But then again your max wattage is transfered at delta T of 0 and at speced delta T at no load at all. Most times adding more capacity for wattage gives lower temperatures since people seem to cool things that have constant generation of heat. Cascading 2 same TECs is just really bad idea. You are moving from air that the colder one touches something like 65w and adding to that close the same from the TEC it self. The other TEC can only transfer 65w and cold side on that will raise. That means hot side will raise and you will have burned TEC. First the hotter one then the colder one.
Give it some load to cool and then show the results, might be different
he has no idea what hes doing. dont bother with this video
RIGHT!!!!
12706 5v +12710 12v = -40'c
Series !!!! Sucess
Thanks for watching!
:)
:)
No, no, no.
You have no cooling the way you are dooing it.
And the cold side tec must be half or less the power rating.
First tec might transfere about 100 watt of heat on the hot side and 50 from the cold side then the next have to pull out that 100 pluss it's own 50 watt and that is way above its limits
thanks for sharing
You are welcome!