Let's discuss about Peltier coolers #6 - Personal air conditioner 

Thanks!

You're welcome. Yes, especially at high currents, the heat from the hot side creeps to the cold side very easily. The hot side requires a very good cooling.

Yep, it is on my list to make a video about it. When you use them for heating, you can get more than 100% efficiency, or more precisely, greater than 1 coefficient of performance (COP).

Thanks! Yes, a single unit is not powerful enough for larger volumes. I wanted to "prove a point" here and show that 1 unit is not enough for a room unlike several videos on RU-vid claim it. Changing the airflow on the cold side is indeed crucial! Check the video series where I built a cooling box. I played around with the number of fans on the cold side and showed exactly what you said. We need to balance the airflow with the cooling power to get optimal results.

​@@CuriousScientist Your point is proven right for me, I also believe that there could be a better build/system to cool/lower the temp to an acceptable degree for a small areas like what I mentioned, especially if the power is not a problem when there is a solar power available. And using a Peltier to build a Dehumidifier is also an interesting topic, please consider it in your experiments.

Dehumidifier is on its way! I actually already bought some "special" heatsinks for the task. I just need some time to assemble everything and make some extra hardware to help running the device at the correct settings.

Thank you!

Hi! I don't expect anything because I _know_ that a single Peltier cannot provide enough cooling. It is enough to read the datasheet of it to know this. I just put this system together to disprove those fake Peltier AC videos that circulate on here on RU-vid. I also have videos on your question. A lot of Peltier coolers are needed to achieve sufficient cooling. So many units are needed that it is practically and economically unfeasible to build one. Component costs and electricity costs are both much higher than that of a regular compressor-based AC. Your 800 W AC provides somewhere between 2-3000 W of cooling power. An 800 W Peltier cooler unit would provide somewhere around 2-400 cooling power, depending on how cold you can keep the hot side...

@@CuriousScientist Ahh okay, I have been watching all your videos on the topic of Peltier devices and I have also been seeing other videos by others claiming to make an air conditioner with one Peltier... And those videos are definitely fake! I just didn't realise that your video was trying to debunk those fake Videos! You have covered much ground! I was hoping that after everything that you have explained, that you may make something that is actually useful out of Peltier devices.... There's another science channel which has made a fridge and a separate freezer using Peltiers and the outcome was very good! The finished product looked like something that you can have in your kitchen! They also used 36 Peltier devices on cooling blocks in a relatively small package that fits inside a pot which they boiled water for the hot side to generate enough power to run a 45W led floodlight! The cold water was coming from a creek.... A very useful device and well designed for camping or emergency situations! As for using Peltiers to cool a small bedroom, I don't think that I have seen anyone try and make one, put it in a window and demonstrate what or if it's possible to achieve any level of difference, but I think that the reason why no one has done such a video is most likely the cost of 20+ Peltier devices let alone having enough power supplies to run it! Solar panels would be great for this purpose but I guess that it's going to take the right person who has solar panels and Peltiers plus the skills to put it all together to test if it would make any difference whatsoever! I honestly believe that there's a lot more that could be done with Peltiers, they behave just like solar panels and thus need a lot of them to be useful..... Using one, two or a few is the same and doing the same with solar panels, you really have to go large or go home! I have over 30 Peltiers and I'm planning on getting more because I know that if I'm going to make something useful, I'm going to need a lot of them.... Oh and one more thing that I just remembered, I saw someone put Peltier devices on one of those Chinese diesel heaters, the heater needs to power a glow plug for pre heating the diesel and run a fan which needs an external power supply, but he added some lithium batteries, a charger and Peltiers so that it can provide it's own power! Brilliant! And very useful! Like I said, it would be sad to see you go through this whole series and not try and make something useful out of it! These are the sort of videos I love.... Anyway, you have a great channel which I have subscribed to and looking forward to watching what the future brings. Have an amazing day!

There is nothing really that I can make from domestic use using Peltier coolers. Peltier coolers are more "scientific instruments", they are used in X-ray detectors, CCD detectors, laser diodes or similar stuff. Not something that one could use at home. Building a fridge is possible and certain companies build wine chillers using Peltier coolers, but it is not budget-friendly. Of course, you won't see anyone building a proper Peltier cooler-based AC because it does not make sense financially. It is expensive to buy all the parts and it is expensive to operate it due to the fact that they are highly inefficient. Now adding solar panels to the equation makes the whole thing more inefficient. You utilize like 20-25% of the power of the sun, so let's say 200-250 W per square meter of solar panel due to the efficiency of the solar panels. Let's say, you want to run a regular AC. A random split AC I looked at which can cool a small bedroom needs about 1200-1400 W. So, you need 6-7 square meter solar panel to borderline run it. A Peltier has much worse efficiency, so easily double or quadruple this number to achieve the same cooling effect. Good luck covering half of your roof just to operate a Peltier-contraption. Yes, Peltiers can generate power as well thanks to the Seebeck-effect. But they are super inefficient and ideally you would need to have a very large temperature gradient to get anything useful out of them. And yeah, you would need a very large array if you want to do something other than lighting up a small LED... Compare the cost of the Peltier coolers and other stuff versus the returns you get from such a system... Once again, there's nothing really useful that you can make out of Peltier coolers for "domestic use". So, I warn you not to go through my series because the "best" I made was a large cooling box, and that's all. Otherwise, you'll be disappointed.

Hi! Have you watched the video? You *need to* cool the hot side and you need to cool it as well as possible, otherwise, the Peltier cooler will overheat. First, it won't cool anything at all, and then it gets damaged because of overheating. The hot side has to be cooled very well, so that side gets the better cooler. The cold side just has to absorb the heat from the environment (in this case, from the forced airflow), so it is enough to have the smaller, regular heatsink. Even with the worse heatsink, the Peltier cannot really keep up with the thermal load. Imagine pushing even more heat to the cold side by using a better heatsink.

Hi! I'm sorry, but $50 won't even buy a proper power supply system that is needed to properly run a few Peltier coolers. I have published a video about an "air cooler", check that, but the full cost of the system is probably x10 more than your budget.

Not even 2 Peltiers will be enough. And if you will use 2 Peltiers, the CPU cooler will probably not be able to keep up with their huge amount of dissipated heat.

@@CuriousScientist well if I still use it, it will give a slightly improved the cooling Power right?

If you put a lot of thermal load on the CPU cooler, you can have a thermal runaway and not get any cooling at all. Peltier coolers require very good cooling on their hot side. If you don't cool them properly, they can end up becoming warm.

Liquid cooled should work with radiators for making air cooler and not ac.atleast

@@bhusanalley7481 the solution to dissipate the heat is already resolved with water, pump, hose, fan and radiator method going outside the room (technically a water cooling method), it works by cooling the hot side of the peltier using a water block, and then the heated water that came from the water block will be pumped out of the using a hose room until it reaches the radiator outside, and then the radiator will be cooled down with a fan, however im still not sure whether the indoor unit will even actually do anything with the peltier My another idea would be for the indoor unit to use water and radiator method just like the outside unit, but instead of blowing hot air, it instead cools down a well insulated reservoir filled with water using a peltier By the way im just looking for a better desk cooler to cool my face while playing some games, but im tired having to keep refilling my freezer ice cube tray and only having like 1-2 hours or less of a cold air, since my area is pretty humid so swamp cooler method dont really work

The usual answer is "it depends". You can have an excellent air cooler and a horrible water cooler too. According to other people's experience a good air cooler with heat pipes could remove the heat faster than a water block. But it might be an expensive adventure to purchase such systems. Water itself however has a huge heat capacity, so you could run the system for a while before noticing any substantial heating on the hot side, simply because the large volume of the water just keeps absorbing the heat. But you have to make sure that you can "throw away" that heat good enough at the radiator side of the water system. Another advantage of the water cooling is that the block that you attach to the hot side is small. You can have the rest of the cooler far away from the Peltier. In the case of the air cooler, you have to design your system around the air cooler. So, yeah, it depends... :)

@@CuriousScientist whick better fan + heatsink or fan + heat pipe?

@@CuriousScientist and is fan with 2300 rpm enough to cold the hot side of perltier? Or higher?

You haven't provided enough parameters. 2300 rpm is just a number. Can belong to a 4 cm or a 12 cm fan. No details were shared about thest of the system...etc. I won't play a guessing game.

2300 rpm belong to the 12cm fan

Thanks! I will build a mini fridge, I just need a few additional parts. Stay tuned!

A small window air conditioner of 12000 Btu's is about 3500Watts. At 50W per peltier that's 70? Peltiers? In addition all (most) of the heat is ejected outside in a compressor based system. A 12000Btu Window A/c is really just enough to barely coo a small room (4M x 4M x 7.5M) with 2 people in it by 10 - 15 degrees F. (Like 30C to ~24C). Imagine a room 70x smaller and 1 peltier will cool that with 50W by the same amount if hot side is vented outside and insulated the same. Also needs circulation of the air as noted in your water freezing experiments.

@@paulpease1788 You are right! The smaller the volume the better the Peltier for the application. I will build a small cooler, so i will test it carefully. But yeah, you saw it from this simple calculation that we really need a lot of Peltiers to match even a small air conditioner.

Why would you add an extra layer of thermal resistance to the system?

I hope you enjoyed them and also learned from them. Greetings from Sweden!

There is no _feasible_ way in a sense that these units are very inefficient, so it takes a lot of electricity to provide sufficient cooling power with them. Furthermore, they generate a huge amount of heat additionally to the heat that you remove from the warm room. So it is not only the power supply but it is also their cooling that makes things difficult.

I am not planning to cool anything with it because it is not really possible in this form. The cooling power of the Peltier is too small for this application.

@@CuriousScientist I whant to cool and heat 60 liter Volume area. That probably means that i need more peltier Elements.

Probably a few extra Peltiers will be needed. I guess you cannot wait 3-4 weeks, but recently I have ordered some large heatsinks and several Peltier coolers for a "more advanced" cooling box than I built previously. Mainly out of curiosity, but it can also be useful for some people who need some "reference" for their own projects. My idea is to run the Peltier coolers at lower performance (~20-30% of their max current) and use a lot of them to provide the necessary cooling power. The reason why it is better to run them at lower power is because you decrease the Joule heating significantly, and you can cool their hot side easier. I will put together all these details and ideas into a realized project in the near future. Stay tuned!

You're welcome!

Hi and welcome! The position of the fan would not really matter. Regarding the solar panel, I would be happy to test it if you buy them for me. Also, I live in a Nordic country, we don't have too much sun here. :)

@@CuriousScientist Thank you for your prompt reply, I guess by putting the fan at you initial position ( as per your video) it will suck the air from the room which it's high temperature then it will be mixt with cool air coming from Peltier, so the result will be not accurate. While if you fan will suck same temperature ( cool air ) and push it out side u will get a better result . Regarding the solar i won't be mind to do it but as you said your location won't have enough sun and you need it to keep it for so long to be charged.

I think you don't clearly understand the thermodynamics behind the cooling process. Guessing and knowing are two very different things. There is a heatsink attached to the cold side of the Peltier cooler which is then cooled down to some low temperatures (lower than room temperature). Now, this heatsink is exposed to the airflow which first carries room temperature (RT) air over the heatsink. Then this RT air is cooled down by exchanging heat with the cooler than RT heatsink. After the exchange, the colder air exits on the other side of the flexible tube. It does not matter if the airflow is pulled or pushed over the heatsink, because ultimately what matters is the speed of the airflow (available time for heat exchange) the temperature of the air to be cooled and the volume of the air that interacts with the cold heatsink.

​@@CuriousScientist once again thank you for your prompt reply and your explanation but you missed my point: I was talking only at the cold side and the position of the fan.

Me too.

You are welcome! I am happy to share my findings and experiments.

@@CuriousScientist I'm wondering if i can ask for your whatsapp number so I can voice call you and discuss some ideas regarding the Peltier coolers. I'm sure you will like them, perhaps you can try them out.

Sorry, but I am not sharing my private data with random people on the internet. You can reach me by mail or on Instagram. But, keep in mind that I am not a free consulting service.

@@CuriousScientist lol it's ok i understand sir. Thank you kindly

Thank you! It is not only sad that RU-vid is full of those videos, but those fake Peltier AC videos have several millions of views... My whole channel does not have that amount. But I cannot do anything about it. I upload my own little experiments and tinkering and that is enough for me.

@@CuriousScientist however I'll refer you to this, where it looks like they're using Peltiers for 'personal' cooling in electric cars ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-bBTtXplenD4.html

Thanks! Glad it was helpful!

It does not change anything. You just decrease the already awful efficiency by introducing another medium to transfer the heat.

@@CuriousScientist use cold water from the river

Yeah, like it is so easy to get water from a river. I will need kilometres of hose and a powerful pump...

@@CuriousScientist deep well? or water from the faucet, if u not pay for

@@CuriousScientist then move close to the river, thermodynamic needs sacrifices

Thank you! I hope too!

@@CuriousScientist ive done 1 similiar project maybe you can try. Im using 1 centrifugal blower blowing into a small car intercooler attached with 4 pcs peltier unit. And a hose for the air into my small room. Its not that cold.. But a pleasant breeze air.

Soon, I will receive something from the post office which I ordered a while ago. That supposed to generate a decent enough breeze and it is using Peltier coolers. Keep checking back from time to time, and you will see the video once I get the device.

@@CuriousScientist wow great... Cant wait for it

Well, if I get some motivation (if you know what I mean) instead of a petition, I can build something similar. But I will for sure not play with glycol for safety reasons. Also, I am not making videos on demand for free. I hope you understand.

Probably. Some people do it, they fill up a cooling box with ice packs, and then run air through it.

Sure, water cooling can help but still won't make things work.