Reon Pocket Keeps You Cool With A Peltier Element

With another summer of heatwaves leaving its mark on our planet, finding a way to stay cool during the day isn’t an easy task. From the morning and afternoon commute in public transport, to busy crowds outside during lunch hour, there are many times when you cannot just find a place inside an airconditioned room to deal with the heat. Exactly for this purpose Sony has successfully completed a kickstarter (in Japanese) on its corporate ‘First Flight’ crowdfunding platform for the Reon Pocket.

Many people probably aren’t aware of Sony’s crowdfunding platform, but it’s a way to gauge the interest from the public for more ‘out there’ products, which do not fit Sony’s usual business model. In this case the Reon Pocket is a Peltier-based device which is placed against the back of one’s neck, from where it can either lower or increase the body’s temperature, reportedly by -13 ℃ and +8.3 ℃ respectively.

Covered in more detail by Engadget and its Japanese sister site, the reported 24 hour battery life refers to the Bluetooth link that connects the device with one’s smartphone, whereas the battery lasts under two hours with the peltier element active. This is probably not too shocking to anyone who knows how a peltier element functions, and how much electricity they consume.

Still, the basic concept seems sound, and there are functioning prototypes. While a 2-hour battery life isn’t amazingly long, it can be just the thing one needs to keep one’s cool during that 15 minute walk to the office in a three-piece suit, without needing a shower afterwards. The device isn’t expensive either, with a projected ¥12,760 (about $117) supplied. Naturally the device will only be on sale in Japan.

Considering the simplicity and wide availability of peltier elements, it’s probably only a matter of time before someone puts their own Reon Pocket-style device together. We can’t wait to see the first teardown.

53 thoughts on “Reon Pocket Keeps You Cool With A Peltier Element

    1. Bollocks. Viruses cause flu, not temperature.
      Why do we get more colds and flu in winter? Because we spend more time indoors, closer to each other, with less ventilation (so more viruses in the air) in drier air (due to heating) causing the sinuses to be drier and easier infected.

      1. Why do we get flu in summer when we get too cold? That scientific explanation is “cool” (pun intended) but it so happens that when you get cold, it’s ALSO easier to get flu. Happened several times to me.

          1. Exposure to cold improves the immune system later, while being cold weakens it in the now.

            It’s easier for the flu virus to get past the immune system when your body temperature is running low (hypothermia). It’s easy to get too cold in the summer as well, by swimming in a cool lake for example, or cycling on a windy day, which stresses and compromises the immune system and allows the flu virus a free pass.

            Also, it’s easier for the flu virus to survive and spread when the absolute humidity of air is lower, which happens when the temperature drops because cold air can hold less water vapor.


      2. I don’t know if it’s correct or not, but I studied with a former trucker driver that said that all the drivers were instructed by their employer to slowly start normalizing the temperature 30-60 minutes before arrival to lower the stress put on the immune system by the sudden temperature change when exiting the truck.

        The employer said that he could see an impact on the number of sick days.
        But then again, the employer maybe just wanted to save fuel.

    2. Your body has 2 levels of immune response: the complement system and the antibody system.

      Having an antibody response takes an enormous amount of energy and puts the organism at risk, so the body tries to avoid doing that if it can. Typically we will get an infection and the complement system will keep the virus at bay, so that the body doesn’t need to go full-blown immune response to fight it. Only when the level of infection gets high enough to be a problem will the antibody immune section kick in.

      So what happens is that we pick up colds and flu’s over the course of the year, but the complement system keeps them at bay and we don’t notice. Then during the fall our vitamin D level drops (6-week half life of vitamin D in the body) and the lower temperatures combine to weaken the complement system and the infections we picked up earlier in the year blossom into full-blown responses.

      Low temperatures and exercise weaken the complement system temporarily. People who take up exercise and start with long workouts sometimes get what’s called “workout flu” – you do a 6-hour hike and immediately come down with the flu. It only happens the first time you do it in a year, and it’s because your workout lowers the complement response and all the flu’s and colds you are holding come into bloom.

      This is why there is a flu season, and it’s why families tend to get the flu at the same time instead of one person getting it first and everyone else getting it 10 days later. In earlier times whole towns in England would get the flu at once, despite there being little or no travel between these towns. Flu season happens all at once, and does not show directly as infection based.

      Back on point: walking around with a small cooling unit for 15 minutes is probably not enough to bring about an infection, but it would contribute to the effect.

    1. I guess you don’t understand how the human body regulates temperature.

      If you are hot then one of the simplest ways to cool down is to expose your extremities to the air. Roll up your sleeves, take your shoes off.

      Reason being that your blood gets close to your skin in those regions, so exposing them helps cool it. Kinda like water cooling, heat is transported via the blood to areas where it can be radiated away.

      One of those areas is just below your neck, where this thing sits. A small amount of cooling to that spot will produce a more dramatic feeling in your whole body. So this is actually a great idea, now that lithium batteries allow it to be reasonably small and flat.

      No need to drag racists and serial harassers into this.

      1. I don’t believe you understand his point. Hes not saying that you cant cool the body by cooling that spot. He’s pointing out the fact you cant actually reduce heat, You move heat. and that device isn’t large enough to effectively remove heat far enough from your body to cool yourself down.

        1. And you missed my point. Think about how effective your forearms are at radiating heat. “Not very” is the answer, yet exposing them makes you feel significantly cooler. That’s because a small change in body temperature feels a lot bigger.

          So it doesn’t need much of a heat sink. The small one it does have, with forced air cooling, is very likely to be enough to keep you comfortable.

        2. Exactly. It has no where to get rid of the heat. It will end up heating up the person. Peltier elements have a terrible efficiency. They make a ton of heat, and to add to the heat, the energy they moved. That’s a shitload of heat you need to get rid of. Putting this under your coat is a joke. It will feel cold for a minute while the heatsink on the “hot” side of the peltier is colder than your skin, but once that heats up a little, the cold side won’t be cooler anymore. It’s just like peeing your pants to keep warm. It only works for a second.

      2. Hes not arguing about how to efficiently cool the body. Hes pointing out that you cant make heat disappear, you can only move heat and that device worn how they show in that video had no where to move the heat too…

      3. > No need to drag racists and serial harassers into this.

        I wish people wouldn’t use labels like this. The term “racist” often means someone dared to criticize a person of color for doing something objectively stupid, or maybe it means they simply won an argument with a Liberal. A “serial harasser” sounds like a label used by someone who can’t take criticism.

        Those terms have no meaning, and shouldn’t be used in a tech forum. In any event, it’s attacking the character of the person instead of making a point about the actual issue.

        1. They have definitions thus they have meaning. In the case of “serial harasser” we have to split the search into “serial” and “harasser” but the combined meaning is obvious.

          Personally I don’t like Thunderf00t as he have narcissistic tendencies and mistakes his ego for logic, never seen him harass anyone or being obviously racist. EEVBlog I can’t comment.

          1. Thunderf00t spent years making hundreds of videos about Anita Sarkeesian. Criticism is fine, but that guy was obsessed. At some point it goes from reasonable criticism of someone’s ideas to stalking them, and the fact that Thunderf00t got paid every time he did it just make it worse.

            EEVBlog certainly used to use a lot of racist slurs like “one hung low”. Also sexist tropes like “in like Flynn (Errol that is).” To be fair I haven’t gone near his toxic channel for a few years so I don’t know if he has toned it down lately (having kids tends to make people moderate their language as they start to think about the effect it has on their own offspring) but he certainly used to get at least one or two of those in every video.

    2. I agree, this is bullshit. There is no way in hell that this tiny peltier can cool so much and still have a two hour battery life, since peltiers are so inefficient. Furthermore, peltiers generate more heat than it can take in, so there is no way in hell the peltier can be cooled with a tiny fan. I’ve personally tried making a peltier effect cooler, and I found out that even if the peltier is submerged underwater, the water reaches 50°C…

  1. A pack of ice cubes or a fan makes much more sense. And ditch that stupid 3 piece suit in hot climate. :-) This peltier device can not get rid of it’s heat anyway if you wear a jacket.
    We should have a look at the release date anyway: I would not wonder if it is April 1st

  2. Lowering body temperature by 13 degrees would put you in hospital with dangerous hypotermia.
    Rasing body temperature by 8 degress would kill you by hypertermia before you could reacht the hospital.
    Wouldn’t they mean the skin temperature?

    1. Yeah, that’s gotta either be a misprint or just blatant fraud. Number one, there’s no way this tiny Peltier with hardly any heat sink could reduce the temperature of something as big and with as high a specific heat as the human body by 13 degrees (Celsius no less!) and if it did you’d be straight up fucking dead.

      Pretty obviously some kind of scam gadget.

    1. So their method effective tricks teh body into thinking it’s cooler.

      Looking at the kickstarter I get the impression that the special T shirt required as well as the device will allow fans to blow cold air between it and the skin and that would have a good effect in lowering temp or certainly tricking the body into thinking so.

      1. I don’t think tricking the body into thinking it’s cool when it’s actually very hot is a good idea in any case, lest you shut down the body’s built-in cooling system which is far more effective than this little laptop fan.

  3. Really curious how well this thing works, since it’ll have to dissipate heat on the other side to make the peltier element effective. Not sure if they’re using a fan and heatsink combination, but otherwise it’ll be hard to keep yourself cool when the differential temperature is ~20 degrees and the element on the ‘outside’ is 40 degrees celcius for example.

  4. In a grand picture, mentioning about the warmer getting weather and a pocket size personal peltier cooler within one paragraph could be either a sign of growing narzicissm in individuals or growing ignorance in mankind.

  5. Peltiers elements have their place cooling small loads like laser diodes but using them for a purpose like this borders on fraud.

    Not sure how effective have a small cold spot on the back of your neck would help when the waste heat is being dumped down your back.

    They use a lot of power and produce a significant amount of heat. In the case of this device, I would be extremely weary of a peltier assembly without a good size heat sink. Operating a peltier without removing the excess heat from the hot side of the element lead to the solder on the junctions within the element melting.

    1. > the waste heat is being dumped down your back.

      No it isn’t, it’s being dumped into the air.

      > In the case of this device, I would be extremely weary of a peltier assembly without a good size heat sink.

      The size of the heatsink is irrelevant, it’s how much surface area it has. And the picture shows this device is blowing air over a grille. It might not be enough to extract a huge amount of energy, but it’s not cooling a 50W CPU here, it just needs to do better than dry skin to air. The rest of the effect is psychological, not thermodynamic.

        1. The point isn’t to cool you down, the point is to make you *feel* more comfortable despite the heat. The amount of energy transferred to the environment is small, but having something cool pressed against certain places in the body is enough to reduce sweating and discomfort.

      1. From what I can see, the fan on the heat sink exhausts through that little window on the special t-shirt. Since the product seems to be marketed toward business men, the commercials show the special t-shirt being worn under dress shirts; the air flow can’t go up through the collar. I would standby the heat being dumped down your back.

        As far as the heat sink goes, using a peltier with a small heat sink with insufficient thermal mass can lead excessively high temperatures on the hot side of the junctions. This is especially pronounced when the element is first switched on.

        Peltiers move the maximum amount of heat when the temperature difference between the hot and cold side is close to zero. When the element is first switched on the it can quickly dump a large amount of heat onto the hot side of the element. Without sufficient thermal mass in the heat sink to dampen the resulting increase in temperature the solder on the hot side of the junctions can melt. The increase in temperature causes the efficiency of the element to decline rapidly until the only Joule heating is present.

        The take away never use a peltier without a heat sink.

  6. Sharper Image sold a similar device back in the late 90’s
    One wore it around the neck like a collar. It pressed a heat sink (Cold side of the peltier device) against the back of your neck, cooling the blood flow there. The hot side of the peltier exhausted to the air via a small but noisy fan.
    Power was supplied by an AC adapter or battery pack – 6 volts as I recall
    It actually worked – but looked ridiculous…

  7. As long as the batteries for this are charged by running a bicycle for one hour at full speed. Otherwise, they are just finding another way to waste energy instead of solving the problem ( that could be done in a better, energy-efficient way )

  8. “With another summer of heatwaves leaving its mark on our planet, finding a way to stay cool during the day isn’t an easy task.”

    Read an article yesterday saying a light-colored roof would go a long way towards helping.

  9. Everyone complains about the heat, no one is doing anything about it, except Al Gore and these folks. The real cause of global warming is all the evil, baaad souls that are burning in Hell

  10. Homeostasis Maya,homeostasis…I don’t think the body can survive minus eight to thirteen degrees plus, proportional band , one would be stone dead! Hypothalmus ……biology class don’t you recall?


  11. Considering I have actually used a gadget similar to what is being described, I would like to add my observations to the ongoing diatribe:

    This type of thing:
    – makes you feel cooler (temperature-wise) but doesn’t do enough cooling to keep you from sweating.
    – makes you look dorkier and your wallet lighter.
    – moves a little heat from one place (you) to your environment while generating even more heat.
    – does nothing to actually cool your body temperature down very much (maybe .1 a degree F)
    – is a stop-gap “feels-good” moderator for people not smart enough to get out of the sun.

    Easiest way to understand what this is doing: Imagine yourself standing in the sun a hot day holding an unopened ice-cold can of your favorite beverage in one hand. If you drink the beverage, you will cool down your core temperature and lessen your sweating temporarily (remember, sweating [evaporative cooling] is one of the ways your body regulates its temperature). If you hold it your neck over one of the arteries going to your brain, you will cool the blood supply going to the brain and get some relief from the heat because your brain will not be stewing in the heat quite as fast. Or, you could actually be smart: get out of the sun, into the shade, and then drink the can of your favorite ice-cold beverage.

    What works better, costs less, looks smarter, and is cheaper to recharge? A wide-brim desert-style floppy hat with a bandana back and a ‘swamp box’ headband.

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