DIY cooling vest

[Anonymous No.947885]

So I made my own cooling vest out of some duct tape and cooling mats. Looks very terrorist, but I'm only going to be wearing it around my house so meh.

It works well, but it only lasts for an hour or so. I want to figure out a way to make it last longer.

The cooling pads I use now are chilled to 4C in the fridge. Icepacks would last longer, but are too cold to comfortably wear so I'm looking for a way to have a solution that freezes at 5-10C so the cooling pads would be solid in the fridge, and melt as they absorb body heat.

There are commercial products that work this way, but they are prohibitively expensive (especially with shipping) and do not disclose their contents.

Any idea where I should start with this?

[Anonymous No.947895]

Open the goddamn window

[Anonymous No.947897]

>>947885
Cooling pad between ice packs and body?

[Anonymous No.947903]

>>947885

It's only a matter of time before a big sports company jumps on this, think long and hard about the choices you will face.

[Anonymous No.947905]

>>947895
It's 40C outside, I don't think that will help.
>>947897
Hmm, that could work, I'll have to try it.

[Anonymous No.947932]

>>947885
Get some high pressure tubing, a decent compressor, if your using it in your house you have no problems with using a fridge compressor so you can just walk around with an extension cord, put a backpack on your back that will serve as the heat exchange. make sure you have a capillary for said exchange. It will last forever and ever as long as you have an outlet near buy.
What is saying is make yourself in to a half man half fridge abomination.
Post results

But if you just want to make the bags stay cold longer get something with a grater thermal capacity than water. There are some foams and pellets you can get in cold packs. Adding slats works too. give the packs added insulation form the outside so the cold is directed toward your body and not the outside.

[Anonymous No.948007]

>>947932
The existing pads are filled with what I would guess is sodium acrylate gel although it could be cornstarch depending on how cheap the manufacturer is. I've also been experimenting with some super saturated calcium chloride solutions which should be able to freeze at temperatures as high as 23C, but I would need a vacuum sealer or something to seal it properly. It's a skin irritant at high concentrations so I can't just put it in zip locks and call it a day.

[Anonymous No.948011]

Pykrete in sandwich bags. Get a fishing vest the kind with lots of pockets including the big one in the back.

Your welcome.

[Anonymous No.948037]

>>948011
That's an interesting idea. I'm concerned the pycrete will be too cold so it will need some kind of insulation. I'm also concerned that because it melts so slowly it might not provide a strong enough cooling effect especially through insulation.

I'll have to do some testing.

With regards to the fishing vest, I tried that first before my duct tape idea, but there was no good way to attach the front panel to the fishing vest since it zips up in the front. It also didn't hold the cooling pads against the body so the pads didn't make good contact.

The duct tape vest is designed like a body armour vest that goes on over your head and attaches with neoprene Velcro strap around the waist, which holds the pads securely against my skin.

[Anonymous No.948043]

>>948037
Fill garden hose with it and wrap it around you like a snake dancer.

Extra credit. Glue rubber snake head on the front of hose.
Bonus burglars look in freezers because people think they are clever but in your pad its a big ass snek waiting. Most likely stuffed in there in a way it jumps out.

[Anonymous No.948068]

>>948043
Wouldn't a garden hose rupture if you froze pycrete in it?

[Anonymous No.948109]

>>947885
>Buy 10' of 1/4 inch diameter tubing and small fish tank filter
>fold tubing In half start twisting at half point till the twist is about a foot long
>connect one of the tubes to the fish tank filter intake
>submerge the other end in a bucket of cold water
> turn on the filter till the entire tube fills with cold water
> take submerged end of the tube and connect it to the outake of the fish tank filter (make shift radiator)
> take the twisted corkscrew part of the tube and insert it into anus
> turn on fish tank filter
> it'll keep your core temp nice and cool for a while
> replace water when it gets too warm

You can also find a way to attach this into a backpack and have the filter run on battery for mobility

[Anonymous No.948121]

>>948109
Rectal cooling, while definitely creative, isn't exactly what I had in mind...

[Anonymous No.948126]

>>947885
get hotel pan
get perforated insert for hotel pan
insert to hotel pan
get ice block
put ice block on perforated insert
put hotel pan on desk or small table
put fan behind hotel pan

alternately, put ice cubes in saltwater and a fan behind that

If you're really set on a vest for some reason, mount a computer cooling radiator or two, a water pump, and a rechargeable battery on a frame, install backpack style straps or pad one side of it and attach it to a vest filled with tubing that you can hook up to the radiator pack.

[Anonymous No.948131]

>>948126
I have a small A/C unit, and if I'm just sitting at my desk that works fine, the vest is for when I need to venture into the rest of my house which I can't afford to cool.

The radiator type cooling vest doesn't work very well when the air temperature is close to body temperature, it would need to be a phase change cooling system (refrigeration) in order to provide any cooling effect, making it expensive and complicated.

[Anonymous No.948168]

>>948131
Well what do you want? Something that cools more in a shorter period of time, something that lasts longer, or something that both cools more and lasts longer, but is stupid expensive and complicated? You aren't going to get all of it at once. Getting another job so you can afford to cool your place would be easier than trying to invent a miracle cooling vest.

[Anonymous No.948192]

If op is experimenting

He should try feet cooling

[Anonymous No.948202]

>>948168
Essentially what I want is this: http://www.firstlinetech.com/product/phasecore-elements-28/

but not only is it out of my price range, they won't even ship to my country.

I'm working on a few different ideas, as I've been discussing above, I really just started this thread so I could see if anyone here had different ideas to try, or practical experience with a project like this.

People seem to be confused so I'll try and describe the project more formally:

Background: I have a medical condition that makes it difficult for me to tolerate increases in body temperature. It's not like I'll die, but if I start to overheat I will be extremely uncomfortable. Unfortunately I live in a very hot climate. I am also somewhat of a poorfag in that I can't afford central air conditioning.

In the past I have treated overheating by lying on a cooling mat an icepack on my head, or by taking a cold shower. Now that I have the cooling vest I can just throw it on, have a cool drink and continue with whatever I'm doing. I also wear it while exercising as a preventative measure. The cooling vest lasts about 1 hour.

Goal: To increase the duration, comfort, and effectiveness of the cooling vest.

Requirements:
- should provide good cooling effect for at least 2-3 hours
- condensation should be kept to a minimum
- must be non-toxic in case of leaks
- temperature applied to the skin should be 5-15C
- must be portable (under 10kg, not overly bulky)

Budget: $50-100

Tools: I have a full workshop, as well as basic chemistry and electronics (soldering station ect.) equipment as my disposal.

Skills: I have basic woodwork, metalwork and electronics skills, including some programming; I have some experience with chemistry labwork (but not much theory knowledge). Unfortunately I have no sewing experience.

Materials: Anything within the budget.

[Anonymous No.948208]

>>948202

Ideas:

1. Try to reverse engineer the phasecore element.

They are described as "Non-toxic, non-flammable salt mixture sealed inside an aluminum wrapper."

My working theory is that they contain mostly a Calcium Chloride solution at a concentration of around 45% w/w.

I'm struggling to get the concentration right in tests because I don't know the exact concentration of CaCl2 I'm dealing with (the source I'm using is dehumidifier flakes with somewhere between 60-90% purity, lab grade CaCl2 is more expensive).

It's difficult to get it to stay in solution since it is super saturated. I find it tends to separate as it cools.

I also need a way to seal it into pouches.

I've also got some Sodium Acrylate but I haven't started testing with it. Apparently some people have had success with it.

[Anonymous No.948221]

>>948208
2. Use standard icepacks with some type of insulation

Potential problems include excess condensation and over cooling.

>>947897 suggested putting icepacks inside the existing cooling pads to keep them cold for longer. This bears further thought.

I'm thinking I could put an opening and some velcro at the top or bottom of the cooling pads (they are folded in multiple layers) so that a rigid or flexible icepack can be slid inside like an armor plate. This would mean the icepack could be swapped out while wearing the vest, extending the cooling time indefinitely.

If this works out, it could be my solution.

[Anonymous No.948229]

>>948221
make a few vests with cheap ice packs and rotate their time in the freezer

[Anonymous No.948235]

>>948229
That's the beauty of it, I wouldn't need multiple vests, just multiple icepacks.

>>948221
3. Water circulating vest.

This idea never got off the drawing board for me, too many problems.

- the cooling hose wouldn't have adequate surface area in contact with the skin (look at how commercial products like this are designed)

- the radiator doesn't have a great enough of a temperature gradient to disperse heat (commercial units use refrigeration to chill the radiator.) This could be remedied by using a bucket of ice water, or (as some have suggested) by running fresh tapwater through the vest continuously. Both of these solutions require a tether.

- cost/difficulty. Building a portable battery powered refrigeration unit with sufficient capacity would require either miniature compressor and A/C parts (I don't know a lot about compressor tech, so I would have to learn), or a ridiculous amount of thermo-couples. Battery power would probably need to be LiPo or a large number of 18650 cells, both of which are expensive. Power management and control circuitry would also be quite expensive. I estimate the project would cost several hundred dollars.

[Anonymous No.948300]

>>948235
Don't forget to test the anatomical aspects... Perhaps you might not need a full vest to accomplish this. I can deal with with all sorts of low temperatures just by keeping my lower back warm. Scaling it down might make it feasible.

Also, you have Graves or something? If so you should save up for some iodine 131...

[Anonymous No.948310]

>>948300
I don't really want to be specific, but suffice to say that my insurance is good enough that I have the best care money can buy and I've seen a number of specialists.

Unfortunately there is no cure and we haven't found an effective treatment that can be tolerated long term without significantly shortening my lifespan. I take a number of different drugs to control the symptoms, but I can't safely take doses high enough to completely remove them.

The disease itself won't kill me (fortunately), but the symptoms significantly affect my quality of life.

[Anonymous No.948316]

>>948300
I've seen some ideas people have for directly cooling people by placing thermocouples on the wrists or the back of the neck, it might be worth a look, but it isn't something I'm currently looking into. It would be much more complicated than what I'm attempting at the moment, and would likely need fans to cool the hot side. I can't see a way to do it without it being the size of something like a pipboy, and it would draw a significant amount of power.

[Anonymous No.948334]

>>948316
>>948300
From my research on the subject the biggest problem with cooling the whole body by cooling a small area of skin (as opposed to heating) is that it causes local vasoconstriction, which prevents it from effectively cooling the blood (due to reduced flow). Some engineers at... I believe it was MIT? Developed a machine that used negative pressure to dilate blood vessels while the extremity is being cooled, allowing athletes to cool themselves down just by placing their hand inside it.

[Anonymous No.948591]

>>948334
This another commercial option being used today. With some creative use of trash bag you won't even get wet.

[Anonymous No.948735]

>>948591
Interesting

[Anonymous No.948759]

>>948121
You need to get the cooling onto the main arteries and veins and shit, that's what they pop out for in hot weather. The chest pack is good but you need to work the pits, the crotch, back of neck, feet, I hear tell the soles of your feet have more pores than any part of the body. Then you need it all to be machine washable, or whatever.

[Anonymous No.948766]

look into medical grade water warming/cooling blankets.
some ppl cant regulate body temp
also look into emergency/bodybuilding body temperature reduction vests/gauntlets/stations

[Anonymous No.948839]

>>948766
Medical grade stuff is ridiculous expensive, but I have looked into them to see how they work.

[Anonymous No.948853]

>>948759
There's a matching panel on my back which balances out the vest.

[Anonymous No.949285]

Bump.. Been thinking about this, i dont think we're whooped yet.

OP: do you have a (even if inefficient) prototype? Maybe we can improve on it?

[Anonymous No.949344]

>>948334

I built a device after that study went viral.

Your hands are one of the biggest heatsinks on the body.

Built a pressure chamber (PVC pipe with an end cap. Ran a piece of copper pipe through it to hold on to. Ran cold water through the pipe. Sealed it with silicon.

Used a flexible pipe coupler on the end with a strong rubber band to make a seal. Finally I tapped a small hose barb into the PVC pipe and hooked it to a break bleeding pump.

Few squeezes was all I needed.

Hand become very uncomfortably cold. Body temp dropped quickly.

[Anonymous No.949476]

>>949285
To which idea are you referring? The only idea that I've actually constructed is the cooling vest in the picture. I plan on upgrading it by adding pouches for placing ice packs into the the middle of the cooling pads.

The phase change experiment is still just a bunch of jars with different concentrations of CaCl2. I can post some pics and more about my methodology and the problems I'm having so you guys can weigh in.

With regards to the thermocouple ideas, I haven't actually bought any yet, I want to have a more detailed plan before I commit any money to it. I could draw up some designs for you guys to tear apart tomorrow if that sounds like something that would be interesting.

[Anonymous No.949478]

>>949344
That sounds very interesting, got any pics?

[Anonymous No.949521]

>>949478
I'm several hundred miles away from it right now.

Have an instructables of a nearly identical build.

http://www.instructables.com/id/CoreControl-DIY/

[Anonymous No.949619]

>>948591
My go-to thing in summer is 2 of those square cat litter buckets filled with cold water and 2 plastic shopping bags over my bare feet. I slip my feet into the buckets and enjoy until the water is warm. Normal round 5-gallon buckets are not wide enough to fit my feet into flat. The cat litter ones have rectangular bottoms. Since they are buckets, I can fill them up quite a bit for extra thermal mass and longer lasting effects. I bet you could set up a thermosiphon flow through some tubing connected to the bucket that leads to a simple heat sink. The heat sink could be massive so the net effect is far better than normal sweat evaporation (sweating doesn't work well here in summer due to humidity).

I also use a wet dorag on my head and a box fan blowing across me. 95F-100F and 85%-90% humidity isn't to be trifled with.

>>949344
I prefer using my feet so I can use my hands for other things. Like shitposting on 4chan in summer.

[Anonymous No.949964]

>>949344

[Anonymous No.949970]

Just use chunks of dry ice to cool the vest. You'll also trail vapour wherever you walk, for extra ghetto points.

[Anonymous No.949977]

>>948235
Are you Willis?

[Anonymous No.949989]

>>949964

[Anonymous No.949993]

>>947903
They already have. Cooling vests have been around since I played high-school football...so over a decade ago now.

[Anonymous No.950016]

I think we might have a bit of a power problem.

At full power 4 IMR 18650 batteries would be drained in a little over two minutes!

Even with two laptop battery packs (from my parts drawer) the gauntlet could only run at full power for 25 minutes.

I'm not sure what kind of duty cycle the cooler would need to be on. Potentially I could run it with PWM to try and maintain a constant temperature and integrate a charging port to power it while in use.

This thing is going to be throwing off a lot of heat from the power supply alone, let alone the hot peltier plate.

Even with 90% efficient power delivery were still talking about 23W from the boost module, 2W from the buck module, plus heat from the batteries internal resistance, plus heat from the vacuum pump, plus up to 200W of heat from the peltier cooler.

It might be more efficient to move the power supply to a belt pack.

[ADOLF !HITLERqi96 No.950025]

Why not have water from a tap going trough it?

[Anonymous No.950068]

>>950025
Because then it would have to be tethered to a tap. The whole point is to be portable.

[Anonymous No.950101]

>>950016
Does anyone have experience building a Peltier cooler driver board?

[Anonymous No.950409]

>>950101
Nevermind I think I've got it.

[Anonymous No.950421]

Anyone have the concept image for the hydranus?

[Anonymous No.950910]

>>950421

[Anonymous No.950913]

>>950421

[Anonymous No.951112]

>>949964
>>949989
>>950016

One thing you seem to be overlooking is that there is no need to have it running constantly. Only when your temperature is high.

If there is no need to keep your temperature stable, just go for a massive drop in temp all at once. If you can drop your body temp by a few degrees overall, you're now well out of overheating territory and should be good for a decent period of time.

Also why do you need it to be portable. The device works in minutes so just keep it by your computer and shitpost for the ~5 minutes it takes to work.

[Anonymous No.951269]

>>951112
Well I have a bunch of elements to test now so I'll have to see where this takes me.

I'll have to make it work before I can make it portable.

[Anonymous No.951312]

Alright, ignoring the vacuum gauntlet for the moment, I'm continuing my experiments with Calcium Chloride as a phase change material.

I'm not sure of the exact concentration of this sample, but it's density is approximately 1.49g/cm^3 +/- 0.01g

[Anonymous No.951321]

>>951312
Prior to heating the sample has two separate layers, solid hydrated CaCl2 crystal on the bottom and a solution of what I suspect is mostly water on the top (although there is probably some CaCl2 dissolved in it.

Room temperature is 26.7C.

[Anonymous No.951325]

>>951321
My lab equipment is pretty ghetto, but it does the job.

A water bath was used to heat the sample to 41C, at which point the CaCl2 appeared to be fully dissolved... or maybe it's a suspension? I don't know, I'm not a fucking chemist.

Mixture was cloudy and no 'grit' could be felt when strring with a glass rod.

[Anonymous No.951327]

>>951325
Sample was removed from the water bath and allowed to cool, stirring and checking temperature every 5 minutes.

[Anonymous No.951331]

>>951327
At 25 minutes the temperature of the sample stabilized at 29C (which is not surprising since room temp was ~28C).

Salt crystals began to precipitate out of solution giving the sample a gritty texture. Crystals could be observed as a residue and the viscosity of the mixture increased greatly.

[Anonymous No.951335]

>>951331
Temperature appeared to increase between minute 25 and minute 30. Temperature was 31C.

I don't know if this was caused by a phase shift, or experimental error. More tests are needed.

Larger crystals were observed in the bottom of the container.

[Anonymous No.951336]

>>951335
At 35 minutes the temperature remained at 31C and the sample was transferred to an ice bath.

At minute 40 the temperature was 24C and crystals had continued to grow, forming a crust around the outside of the container where it was in contact with the ice water.

[Anonymous No.951340]

>>951336
At 50 minutes the mixture was a thick gel all the way through and had become completely opaque.

Temperature remained constant at 22C, very promising.

[Anonymous No.951349]

>>951340
At 60 minutes solid crystal had begun to form around the edges of the container, the center remained gel. Temperaure remained constant at 22C.

At 65 minutes the entire sample was one solid crystal. It was so solid that the thermometer could not be removed from the sample. Temperature had fallen to 20C.

This is exactly as I would expect for a 22C PCM.

[Anonymous No.951353]

>>951349
At 65 minutes the sample was placed back into the warming bath.

Somewhat surprisingly the sample decreased in temperature to 15C at minute 70. I theorize this is due to the phase change back to liquid absorbing heat from the center of the sample (where the thermometer is located) as well as the water bath.

[Anonymous No.951357]

>>951353
At minute 85 the temperature had risen to 22C, the bottom of the sample remained as a solid crystal while a layer of cloudy liquid formed on top.

At minute 90 the temperature had risen to 26C, the sample was almost entirely liquid, with only a few crystals in the bottom of the container.

[Anonymous No.951359]

>>951357
At minute 105 the temperature had climbed to 42C and the sample had returned to a completely liquid state with no observable crystals.

Experiment terminated at 105 minutes.

<Unscientific results table.

Anyone have any thoughts before I repeat the experiment with another sample?

[Anonymous No.951402]

>>951340
Looks like cum

[Anonymous No.951407]

Adam Savage actually had two of these exact things while walking around comicon, apparently astronauts use these which is pretty cool, his was loaded up with ice though

[Anonymous No.951410]

>>951407
Astronauts' cooling suits actually use circulating water to cool or warm the astronaut as needed. The water circulating vests seem like they would be simple to make, but they're actually not. You need very narrow, flexible channels closely packed over a wide area. Just wrapping yourself in aquarium hose won't do shit.

[Anonymous No.951477]

>>951359
Apparently I know even less about chemistry than I thought.

Based on some pointers from a chemistry IRC I'm going to have to do a major redesign since the existing design was based on a fundamental misunderstanding of how solutions change phase.

[Anonymous No.951487]

Added an icepack pocket to the gel vest.

[Anonymous No.951489]

>>951487
1kg ice pack.

[Anonymous No.951494]

>>951489
Don't know why 4chan is turning my pictures sideways.

Anyway, vest weighs ~7kg with one icepack, 8kg with two.

It's comfortable enough at this weight, but I feel like much more than this will start to be heavier than I'd like.

[Anonymous No.951832]

>>947885
Buy a fucking AC unit

Or if you want to go real science ghetto since your only wearing it at home...

Get yourself:
- some copper and vinyl tubing
-insulation of some sort
-tape, zip ties, twine... Your choice
- pipe clamps
-a water pump or radiator pump
>depending on how cold you want it to get
-Water or antifreeze (see above)
-a drill
-and whatever type of sealant that floats your boat

1) drill 2 holes in fridge or freezer
>again, depending on how cold you want it to get

2) get a nice long length of copper tubing, work it into a spiral or make whatever funky pattern you like, I really don't care.
>Just so long as it all fits in there and has plenty of length to cool the liquid inside.
Stick both ends out of the holes
Seal up the gap between pipes and holes

3) attach pump to one end of copper tube to feed into cooling unit
>use your head to pick which pump to use

4) get a very long length of vinyl tubing. Twice the length from your fridge to the farthest reach of your house, plus whatever length you want to run through your suit to cool you down.

5) from the middle of the vinyl, interlace it through your cooling vest however you like and secure it in the whatever way you decide to.

6) attach and clamp one end of the vinyl tube to the pump, partially attach the other ends, charge the line
>again, use your head for water or antifreeze
Once charged with all air removed, fully attach and clamp other end.

7) place the two separated parts of the vinyl tubing together with insulation between them and tie together however you like

8) put on vest, turn on pump, look ghetto as fuck, stay cool

Your welcome

[Anonymous No.951838]

race car drivers use a coolsuit , googlllllit

[Anonymous No.951889]

>>951832
I already have an A/C...

It looks like this. And I think I've got just about as much out of it as I can.

[Anonymous No.952034]

Cooling Vest Mk1.1: Uparmour mod (lol)

Added a cold pack to cover the neck and shoulders. The back of the neck and the anterior surface of the shoulders are highly vascular.

With the icepacks loaded into the vest the inner surface gets too cold, even through two layers of gel (uncomfortable and causes vasoconstriction, reducing cooling effectiveness).

I may have to add some insulation to the inside of the vest, or to the outside of the icepack.

A layer of microfiber on the inside of the vest may make it more comfortable and absorb condensation/perspiration. A layer of neoprene on the outside may decrease heatloss to the outside, extending the use time of the vest.

Anyone have experience with this sort of thing? Advice on materials and how to attach them?

[Anonymous No.952038]

>>952034
>The back of the neck and the anterior surface of the shoulders are highly vascular.

The subclavian artery passes close to the surface (obviously near the clavicle), and the transverse cervical artery passes close to the surface (obviously near the cervical spine).

This thermal imagery helps to illustrate the cooling potential of the this area.

[Anonymous No.952041]

>>952034
Forgot picture.

[Anonymous No.952050]

>>952038
Based on this image I may raise the back panel a couple centimeters. The positioning was originally based on body armor vests which have the plate positioned to protect the heart and lungs, obviously that isn't a concern here.

[Anonymous No.952055]

>>952050
My front panel placement looks pretty good, but I may look into adding a trapazoidal panel that hangs over the crotch and inner thighs.

[Anonymous No.952059]

>>947885
>Icepacks would last longer, but are too cold to comfortably wear
A bit of insulation between your body and the icepacks would resolve this issue by slowing the heat transfer from your body, and it would help them last even longer to boot. Also, it couldn't hurt to insulate the packs from the environment.

>I'm looking for a way to have a solution that freezes at 5-10C so the cooling pads would be solid in the fridge, and melt as they absorb body heat.
This can be done even with brine. Saturated brine freezes, by definition, at 0* F which is about - 20* C.

[Anonymous No.952084]

>>952059
I want something that will freeze at +5 to +10C. Brine (. NaCl) decreases the temperature at which water freezes, to a minimum of - 23C at the eutectic point, then starts to increase again as it approaches saturation at ~-20C.

That's why I'm experimenting with CaCl2 solutions. The hydrated salt (in the CaCl2.6H20 configuration) experiences a phase change at ~+23C.

As for insulation, that's something I'm working on now...

[Anonymous No.952108]

Tldr the whole thread. Is it to humid to make a garbage can evap cooler for the house?

Suck air in from outside, push it through a wet substrait into the house, open a window somewhere else so the wet air leaves the house. They're only effective when it's 20% or lower humidity though.

[Anonymous No.952123]

>>952108
Humidity is currently 47%, and rarely goes below 30. I have a small evaporative cooler that I run if the humidity goes below about 35, and I switch it off once the humidity reaches 50. It doesn't do very much, but it's better than nothing.

[Anonymous No.952543]

>>948202

If I pull that vest off, will you die?

[Anonymous No.952553]

>>952543
It would be extremely painful.

[WastedProps No.952558]

the tubing idea must work, as they made similar suits up for the Martian movie to keep the actors cool. I just built one and works well

[Anonymous No.952579]

>>952123
Damn that sucks.

Have you ever worn sweat wicking shirts? They can help enhance the effects of sweating. You sweat, it's drawn away with the heat. I wonder how it could be used, in a humid clumate, to draw condensation from an ice pack to cover more area.

[Anonymous No.952592]

>>952579
I have, and that's an interesting idea, I will have to investigate further.

[Anonymous No.953607]

>>952558
I can't seem to find a lot of detail on their cooling suits:http://www.wired.co.uk/magazine/archive/2015/10/play/the-martian-nasa-costume-design

But from the sounds of it they would have utilized commercially available cooling suits of the same type used by race car drivers.

I never said the tubing idea couldn't work, only that home brewing the actual tubing part of the device would be very difficult. The cooling tubes inside one of those cooling vests need to be very thin flexible, not insinuative to heat, curve around tight radius turns and not cause a lot of flow resistance.

It's not as simple as my original idea of wrapping a vest in acrylic aquarium tubing. The tubing was too hard to conform to the body and so had little contact area with the skin, the plastic prevented good heat transfer, and bending it too sharply caused it to kink.

The most efficient design for a cooling pad of this type would be either wide flat tubes, or a capillary type design where one input tube splits into a large number of smaller tubes which run parallel to each other over the area where the heat is being exchanged and then recombine into one output tube.

[Anonymous No.953610]

>>952558
I'd also love to have a look at the one you build, especially if you had some designs you could share.

What type of tubing did you use and how did you go about constructing the refrigeration pack?

[Anonymous No.954223]

>>952543
>iunderstoodthatreference.gif

[Anonymous No.954261]

>>950913
The picture is funny as long as you don't realize that ultra marathoners actually "drink" water by inserting it in their anus. After that it becomes hilarious.

[Anonymous No.954297]

>>954261
i dont understand why the anus sucks in water or anything for that matter, what could it be absorbing in the shitter pipe, shit? gross as fuck

[Anonymous No.954309]

>>954297
colon is where water reabsorption happens

[Anonymous No.954312]

>>954297

IIRC my biology class from 14 years ago taught me that the colon is where most fluid is absorbed.

Hence enema's

[Anonymous No.954529]

>>948121
Rectal cooling is also highly effective against dehydration
>protip, you can't drink seawater unless you stick it up your bum

[Anonymous No.954575]

>>954529
Sticking seawater up your butt won't make you hydrated. The sodium level of seawater is such that it will actually suck more water into your rectum to equalise the osmotic pressure, giving you watery diarrhoea in which you will shit out even more water than you just put in.

The only reason to use a hypertonic sodium solution is to restore sodium levels in someone that has become hyponatremic, and even then seawater, with ~3.5% NaCl w/v, is very strongly hypertonic, compared to your blood which has ~0.9% NaCl w/v.

So no, salt water will not hydrate you, regardless of the route by which it is introduced into the body.

[Anonymous No.954587]

>>954575

[Anonymous No.954590]

>>954587
I'd say that I don't get it, but apparently I do and it just isn't funny.

I realise now that you were pretending to be retarded, unfortunately you're still too autistic to understand that just saying something incorrect isn't a joke.

[Anonymous No.954622]

OP, you might want to consider a wax based phase change material. Wax melting can store quite a bit of heat.

>>951832
AC units aren't that portable, but you can make small ones:
http://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=2182&context=iracc
https://patents.google.com/patent/US20040129018A1

Look up microclimate cooling systems.

[Anonymous No.954624]

>>954622
Thanks for the article, that looks like it will be highly relevant to my interests.

[Anonymous No.954627]

>>954624
and check this out, you can buy tiny compressors for portable cooling systems from china:
http://www.alibaba.com/product-detail/BOYARD-miniature-refrigeration-with-R134A-24v_60308737536.html?spm=a2700.7724838.30.216.UP8ROx

Damn you china! Always stealing our tech and making it cheap.

[Anonymous No.954632]

>>954627
Oooh!

It's a bit out of my price range ($220 for one component), but if I ever decide to put $400-600 into this project this'll be the kind of thing I'm looking for. Searching through scrap I'm unlikely to find a compressor that small - high end car fridges don't end up in junkyards (or on craigslist) that often.

Random thought off the top of my head is that if I had all the water circulating parts of the suit I could put a brick of frozen brine (3-4kg) into the backpack section in an insulated compartment filled with alcohol (in place of the refrigeration system) and run the circulating water through a heat exchanger in this compartment to chill it.

Dry ice could take the place of the brine brick, and would be much more effective, but I'd have to be careful to ensure the water never stopped circulating in the heat exchanger to avoid freezing (or use alcohol as the circulating fluid, reducing its heat capacity), and I can't make dry ice in my freezer.

I could use a thermostatic mixing valve to control how much of the circulating water bypasses the heat exchanger in order to keep the circulating water at a constant temperature... Thoughts? Obviously I'm getting ahead of myself and suit design is the first hurdle.

[Anonymous No.954649]

>>954632
>>954632
>>Random thought off the top of my head is that if I had all the water circulating parts of the suit I could put a brick of frozen brine (3-4kg) into the backpack section in an insulated compartment filled with alcohol
I tried to do something like that for cheap by sewing some aquarium tubing into a shirt and passing cold water through it.

It didn't work very well, turns your you need a lot of tubing! to get any cooling! It also turns out that electric watergun pumps don't run continuously.

I don't see any reason why that would not work. A big block of ice and circulating water is what most personal cooling systems use anyway. Might want to use antifreeze so stuff doesn't freeze up. Why worry about keeping the water at constant temperature?

[Anonymous No.954680]

>>954649
I have some posts further up about why aquarium tubing doesn't work for this, but mostly the diameter is too large, the walls are too thick and insulative and they're not flexible enough, both in terms of making sharp turns, and the fact that the cross-section stays circular and doesn't flatten on your body (low area of contact.)

The temperature control is important because too much cooling could cause hypothermia and too little is pointless. Different activity levels and environmental conditions (standing in/out of the sunlight, 35C vs 45c, walking vs sitting down, ect.) will place different loads on the system.

This is based on a though experiment since I haven't studied thermodynamics, but it seems to me that in order to increase the cooling effect you can't just increase the flow rate. An increased flow rate would decrease the amount of time the water spent in the heat exchanger, meaning it won't cool down as much. This theoretically results in no net change in the cooling. (which I guess you could quantify in watts similar to an air conditioner cooling capacity).

It will also spend less time flowing over your body, meaning it doesn't heat up as much doesn't heat up as much, meaning that the temperature difference between your skin and the circulating fluid will be greater resulting in more cooling, but the difference in temperature between the circulating fluid and the cooling pack will also be smaller. The cooling capacity of the system would remain largely unchanged.

Decreasing the flow rate would mean that the water has more time to heats up over your skin, but also that it cools down more in the radiator.

[Anonymous No.954683]

>>954680
When I think about why this is, it seems like all increasing the flow rate does is reduce the temperature difference in the circulating fluid approaching a theoretical state where the whole loop would be the same temperature at infinite flow rate. Conversely decreasing the flow rate increases the temperature difference. The cooling rate of the system would only start decrease once the circulating fluid reached a point where part of the loop was as hot as the object you were trying to cool, or as cold as the ice.

In a compressor based system you have a similar problem, but for a different reason. The refrigerant has to be maintained at specific temperatures and pressures so that the phase change occurs in the right part of the circuit, and to prevent ice from forming in the evaporator/overpressure in the condenser. That's why air conditioners operate on a duty cycle where they turn the compressor on and off at a high/low temperature to maintain a temperature range, rather than providing a continuous cooling effect at reduced power. Power settings on an air conditioner refer only to fan speed, not cooling power.

[Anonymous No.954684]

>>954683
Since our suit's circulating fluid volume in our suit has a large surface area compared to its volume and is being heated, it needs to be continuously cooled, or utilise a large reservoir. This is the opposite situation to a refrigerator, in which the volume being cooled is well insulated against temperature changes.

Since compressors don't like being turned on and off in short periods of time, the solution I've come up with is using a thermostatic valve to allow some of the circulating fluid to bypass the heat exchanger, thus maintaining the temperature of the fluid independently to the duty cycle of the compressor (the temperature of the heat exchanger will increase while the compressor is off and decrease while compressor is running maintaining a temperature range such that the mixing valve is capable of delivering water to the suit at a constant temperature).

If suitable components can be found it may be possible to use a 100% duty cycle, which would make the system smaller, simpler and more efficient.

Apologies for rambling wall of text.

[Anonymous No.955224]

OP, if you're going to blow $600 on this you might as well buy a commercial unit.

[Anonymous No.955651]

>>955224
Not really the point of diy.

[Anonymous No.956643]

Bumping to keep alive.

I work too much and haven't had a chance to update.

[Anonymous No.956720]

op u suck at chemistry dawg
dry that shit under vacuum

[Anonymous No.956734]

>>956720
I'll be the first to admit that I don't know what I'm doing with regards to chemistry.

[Anonymous No.956833]

>>947885
http://www.amazon.com/F-A-S-T-FA1210-L-Shirts-Original-Cooling/dp/B00N34GCRU

[Anonymous No.956843]

>>956833
>nothing under the pits

[Anonymous No.956854]

>>956833
This doesn't include the cooling unit and costs $250 to shop to my country :(

Still, that's pretty much what I'm looking for.

[Anonymous No.956872]

>>947885
>only going to be wearing it around my house
overthinking this op
if you are sitting in one place fill a kids paddling pool with water and put your feet in it you will stay cool.
bonus: keep ice and drinks in the pool too.

if you need to move around your house simply tape poly sheets to your floor and flood your house a few inches

[Anonymous No.956873]

>>956872
My house has two stories, what's they best way to set up a pump to circulate the water back to the top of the stairs after it flows down?

[Anonymous No.956877]

>>956873
use your brain
heat rises, stay out of the second floor during the day

alternatively just open a door to outside and let your basin/bath overflow upstairs and flow naturally downstairs then outside.

[Anonymous No.957248]

>>947903
>>949993
There are some really nice ones made for use in nuclear power plants. Very spendy though.

Apparently hyper-milers use them in the summer so they can keep their A/C off and windows closed.

[Anonymous No.958892]

>>957248
Any links to pics of the nuke plant ones? I'd like to see if I can copy any of their design.

[Anonymous No.959238]

OP here, I'm starting to think this tread is becoming a bit too scattered so I might make a more specific thread if this one dies.

Anyway, what I'm looking at now is how to make custom shaped ice bricks to fit my vest in the OP. I've tried soft icepacks and they won't stay in position (slump to the bottom), hard ice packs are too flat and don't allow the vest to conform properly to my body.

What I want to make is a pair of curved icepacks. My first thought was to take a heatgun to some flat icepacks and try to bend them, but I'm not sure if that's going to work.

The more labor intensive option would be to melt down some milk bottles and remold them into the shape I want... problem is I'm not sure how to mold something with a cavity inside it, especially something that has to be water tight.

Third option would be to cut and bend a perspex panel to the shape I need and attach soft icepacks to it. I'm thinking this would be the most practical option.

[Anonymous No.959241]

>>959238
why not stitch the soft icepacks together to make your vest? you'll end up with a flexible single piece that you can take off and put into a freeze to cool.

[Anonymous No.959246]

>>959241
The soft icepacks I have are plastic rather than fabric and have narrow seams so I'm not sure how well they would hold if stitched together.

I'd also need to find a good way to insulate them since they'd be far to cold to just wear over a t-shirt.

It's a definite possibility though.

[Anonymous No.959266]

>>959246
And why couldn't you encase them in a fabric sleeve?

[Anonymous No.959269]

>>959266
I haven't really done any sewing before, but I suppose I could make a fabric sleeve for each icepack... and that would mean I could put insulation inside the fabric as well.

Since I don't have a sewing machine it would take a longass time though.

[Anonymous No.959601]

Fuck you and fuck your every other day posted vest.

[Anonymous No.959633]

>>959601
Way I see it, at least I'm giving updates. 90% of threads these days just ask a question with insufficient details and never respond.

>Inb4 /diy/ was always shit.

[Anonymous No.959642]

>>947885
>take off clothes
how hot is it in your house?

[Anonymous No.959658]

>>959642
Sometimes it can get to over 40°C inside. Highest outside temp this summer was 47°C.

Most days the inside temp hovers around 29-34°C.

Obviously the most practical solution would be to buy a more powerful air conditioner and never leave my room, but this is a project of mine.

[Anonymous No.960498]

>>959269
>insulation inside the fabric
Take a look at ceramic fabric, it's the hip new shit in insulation.

>longass time
best get started, you don't have a lot of options.

[Anonymous No.960568]

Get some rubber tubing, a small pump, a small radiator, maybe some small fans and a battery. I guess a reservoir, too. Water cool your body.

[Anonymous No.960574]

>>956873
>dig hole
>pump cool air from ground into vest
>be confined to your residence until temperatures drop again
>be comfy

living the dream