Air conditioner ‘in a patch’ provides portable cooling
nature.com
nature.com
Since then, I've thought that something like a simple strap for the hand which had a copper plate for the palm and a bunch of heat dispersal fins like on a GPU on back of the hand, with some sort of liquid running through it to help pull out the heat would probably help quite a lot to help cool you down while exercising...
1. https://news.stanford.edu/2017/12/27/cooling-glove-helps-ath...
Although... 2017? Hmm. I thought I remembered reading about it 5-10 years ago. Maybe an earlier step in the research?
Referenced here: https://slate.com/technology/2012/09/avacore-technologies-ma...
1. https://www.sciencedaily.com/releases/2004/10/041006085310.h...
2. https://gizmodo.com/stanford-is-building-a-body-cooling-glov...
I heard about them in a motorsport context (race cars typically don't have AC since it adds weight and the compressor uses a significant amount of engine power) but apparently they're marketed to firefighters and industrial workers too:
I think the end result was a boot that lowered the pressure of the foot, then circulated warm water against it. The person could stay in 32F water indefinitely.
But the article also talked about core body temperature and exercise. High core temperature was a limit on endurance. With a device to keep your core body temperature even, you could basically exercise at high levels for long periods of time.
I don't know why batman doesn't have something like this on his utility belt, especially when he runs around in heavy black clothing on hot sunny days.
> High core temperature was a limit on endurance. With a device to keep your core body temperature even, you could basically exercise at high levels for long periods of time.
Using this cross-disciplinary analysis- clearly, people have bad TIM between the heat-generating components and the IHS (skin). The solution, then, is to either replace folks' visceral fat and so on with liquid metal, or to remove the skin and fat entirely and cool the important parts directly.
Okay, so the comparison might not quite be one-to-one, but...
Keyword being "feel", as opposed to "actual"
I've had random ideas like wearing a wetsuit that regulates the temperature at right at skin-level, so something like this patch is both validation and a marked improvement.
No. What matters is that your body doesn't overheat.
In the absence of devices like the watch, your feeling of being comfortable enough correlates well with your body not overheating. But if you are wearing a device like the watch that fools your body's perception of comfort, you can feel comfortable while your body is actually overheating. That's not good.
> I don't actually want to change my body temperature by 5 degrees, I'd die.
That's not what the patch does. What the patch does is keep your body from getting hotter in an environment where it otherwise would. And you can tell that it's doing that because you still feel comfortable, and the patch isn't fooling your body's perception of comfort, so if you feel comfortable, you're ok.
If you start feeling too cold, you just take the patch off. So you don't need to worry about your body temperature dropping.
Oh, so everybody stays out in the hot sun all day? Nobody stays in the shade? Nobody goes indoors? Nobody has houses designed to stay reasonably cool when it's hot out? (There are plenty of ways to do that without A/C.)
If people don't change how long they stay out--just go out for short periods to do something, then go somewhere where they can cool off--I have no objection to them using a device to help them feel more comfortable. But uncoupling your natural perception of your body's condition from the actual state of your body is always risky.
I sweat more than needed. Tricking my body into thinking it's 5 degrees cooler wouldn't make me overheat, it would just make me more comfortable.
Meaning, you get too cold when you sweat?
> Tricking my body into thinking it's 5 degrees cooler wouldn't make me overheat, it would just make me more comfortable.
Would it stop you from sweating as much?
At lower temperatures, parts of me get colder than necessary. And there's lots of room for my skin temperature to go up safely that my body is not making use of.
At higher temperatures, I'm already past saturation on evaporation, and the excess just dehydrates me.
> Would it stop you from sweating as much?
Well I sweat less when it's colder. So whatever definition of 'feeling' colder is necessary to cause that effect, that's the definition I choose.
Then you wouldn't want to wear a device that made you feel even colder, would you?
> At higher temperatures, I'm already past saturation on evaporation, and the excess just dehydrates me.
And making you feel cooler would not change that your body is not actually being cooled--if you're at saturation, your body can't cool itself. So to avoid your body overheating, you would need to go someplace that is actually cooler. Just making you feel cooler wouldn't help. (You might get some increase in the time you could stay outside if your body sweated less and therefore dehydrated less.)
Yes I would, because five degrees colder than that is still comfortable, but being wet is not comfortable.
> And making you feel cooler would not change that your body is not actually being cooled--if you're at saturation, your body can't cool itself. So to avoid your body overheating, you would need to go someplace that is actually cooler. Just making you feel cooler wouldn't help. (You might get some increase in the time you could stay outside if your body sweated less and therefore dehydrated less.)
I'm not asking the device to magically prevent overheating. I'm saying that the lower amount of sweat wouldn't be a downside, because there would still be enough.
Also I don't actually overheat because I slow down and avoid pushing myself to that point.
This is a tangent anyway, it's the slightly-over-room-temperature situation that I really care about.
The other is just just pumping away heat.
Pumping away heat is probably better than fooling your brains thermoregulation algorithms. But maybe heatstroke is your thing.
For example, those $20 in-car cool boxes.
I keep meaning to tidy up my design work for this and stick it online under some sort of open source licence. I'm not sure what the best one is for hardware projects, though the GPL will presumably do.
Im also pretty fond of Purple products (their original pillow and any of their mattresses) as they don't get much warmer when you use them.
Also, they raise the humidity, which in itself has many drawbacks.
A simple fan can be remarkably effective.
On very warm days, wear cold wet socks to bed, or in extreme cases a cold wet shirt.
Get a breeze going through the room if you can, open windows in two different walls or something, the air outside may be hot but it's still better to have it moving.
The core of this device is a Peltier heat pump.
I'm sure it's great for keeping cool in the summer, but there is no way they'll ever work out for cooling buildings. They're fundamentally inefficient due to needing to be built of materials that conduct heat in one direction and insulate in another, while simultaneously conducting electricity and having a large bandgap. Such materials have not been found and are unlikely to exist.
Anyone technical proofing the article should have been aware of that, and should not have allowed such claims to get into the article.
Single phase gas turbine refrigeration can theoretically get to the Carnot efficiency limit, and in reality gets close to it.
> The use of such devices could reduce the demand for energy to power central air conditioning by 20% in typical buildings, and enhance a wearer’s comfort outdoors, the authors say.
Well then, another contribution: a few years ago I have found that several months of strenuous cargo exercise made me not care about heat, even the wet heat. I would still sweat and all, but it wouldn't be nearly as bothersome as it was earlier.