#129068 - 04/02/08 03:50 PM
A different kind of survival vest
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Rapscallion
Carpal Tunnel
Registered: 02/06/04
Posts: 4020
Loc: Anchorage AK
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I hadn't seen or heard of this here before, but I really like the idea. Solatec Survival Vest This could be a great little addition to a survival kit for cold weather. Having that pocket of air around your midsection ought to be a lot like a down vest. Anyways, it looks worth it to me.
_________________________
The ultimate result of shielding men from the effects of folly is to fill the world with fools. -- Herbert Spencer, English Philosopher (1820-1903)
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#129080 - 04/02/08 04:40 PM
Re: A different kind of survival vest
[Re: benjammin]
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Old Hand
Registered: 03/19/05
Posts: 1185
Loc: Channeled Scablands
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Interesting idea.
When dead air spaces are above about 1/8" they lose insulating ability due to air movement. That is why you need some down etc. between the outer barriers. Something like the blizzard bag in a vest would probably work better.
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#129085 - 04/02/08 05:04 PM
Re: A different kind of survival vest
[Re: clearwater]
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Rapscallion
Carpal Tunnel
Registered: 02/06/04
Posts: 4020
Loc: Anchorage AK
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Really, I always figured that so long as the captive air didn't have an efficient means of conductive heat loss to ambient, it would retain it's insulating characteristics. I am also thinking that the reflective reabsorption from the outer layer will make the air chambers virtually effective insulators.
Now if the outer layer were wet cloth, I would expect that the vest would be worthless, as the thermocouple to ambient would be way too efficient.
One would think that, given it's construction characteristics, the thermocouple from the body side of the vest would be very efficient in comparison, thus allowing for a much higher entropy because the air in the chambers is captive and the weak thermocouple doesn't promote any closed cell loss.
In an open cell environment, such as sleeping bags or breathable down vests, the 1/8" captivity seems much more realistic. Loft becomes a factor because air movement is restricted/diminished due to macropore resistance which limits convective air flow, but in a closed cell system, I always figured the lack of any air flow fairly negated any convective heat transfer to ambient, except for a negligible amount due to the skin effect of the structure itself.
Kinda like when I stuff myself into one of them emergency survival bags and bind up the opening real good, leaving just a breathing tube sticking out, then proceed to overheat in about 3 minutes.
_________________________
The ultimate result of shielding men from the effects of folly is to fill the world with fools. -- Herbert Spencer, English Philosopher (1820-1903)
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#129089 - 04/02/08 05:20 PM
Re: A different kind of survival vest
[Re: benjammin]
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Hacksaw
Unregistered
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The vest would be good at blocking direct conductive heat loss but if the air pockets were big enough heat can still be lost via convection. Even if the air is 'still' the act of the air heating, rising, cooling, falling, expanding, and contracting will move it enough inside the pockets to dissipate some heat. Looks like the vest has a lot of air chambers and that will help a great deal at preventing air movement.
Better than a straight sheet of space blanket though as far as insulation goes.
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#129119 - 04/02/08 08:29 PM
Re: A different kind of survival vest
[Re: benjammin]
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Old Hand
Registered: 11/09/06
Posts: 870
Loc: wellington, fl
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This is intriguing.Maybe an entire suit could be devised using bird flu suits as a base: http://www.sciplus.com/category.cfm/subsection/48044 LG. FLU SUIT $5.95 EACH Take two of them, nest them, and seal the holes with elastic, and inflate the space between with a flexible straw. I suppose if convective loss due to open space in the air chambers is an issue, you could kill birds, pluck them, and stuff the down into the chambers...
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Dance like you have never been hurt, work like no one is watching,love like you don't need the money.
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#129123 - 04/02/08 09:19 PM
Re: A different kind of survival vest
[Re: MoBOB]
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Carpal Tunnel
Registered: 03/11/05
Posts: 2574
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Its an interesting idea, however for the same price (used) slightly bigger bulk, why not just pack a fleece or down vest?
Teacher
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#129133 - 04/02/08 11:29 PM
Re: A different kind of survival vest
[Re: TeacherRO]
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Geezer
Registered: 01/21/04
Posts: 5163
Loc: W. WA
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Just get a few feet of Reflextix Insulation, cut a keyhole head opening in the middle, pull it over your head and stick the sides together with duct tape.
Reusable. Cheap. Can also be used as a stadium pad.
Sue
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#129143 - 04/03/08 12:57 AM
Re: A different kind of survival vest
[Re: benjammin]
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Enthusiast
Registered: 10/21/07
Posts: 231
Loc: Greensboro, NC
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I hadn't seen or heard of this here before, but I really like the idea. This could be a great little addition to a survival kit for cold weather. I picked up a couple of these last fall and kept one in the vehicle kit over the winter, while the other one resides in my primary BoB year round. They are intended for single use, although the instructions indicate that they can actually be deflated and reused if you are careful and take your time. Since I can't seem to even repack an AMK Heatsheet back to it's original size, I haven't tried inflating one of these to check out its real world performance (the concept seems valid enough though). Speaking of Heatsheets, it's very similar in construction (and therefore noise level) as opposed to the old noisy Mylar space blankets. Its an interesting idea, however for the same price (used) slightly bigger bulk, why not just pack a fleece or down vest? Good luck finding a fleece or down vest that weighs less than 53g and packs smaller than a deck of playing cards. I was out camping a few weeks ago and the overnight temperature dropped to 25°F (about as cold as it ever gets around here) and I was >>>||<<< close to throwing one of these on inside the sleeping bag. Jim
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My EDC and FAK
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#129154 - 04/03/08 02:02 AM
Re: A different kind of survival vest
[Re: Paragon]
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Crazy Canuck
Carpal Tunnel
Registered: 02/03/07
Posts: 3238
Loc: Alberta, Canada
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Hmm, mixed feelings about this.
There may be some value to this in generally mild climates, where you wouldn't normally expect to get cold. So in the short term, maybe it's better than nothing.
Moisture retention is the big consideration. Really, this is a space blanket with a plastic bag draped over top. If you wear this over your clothing, you will quickly become damp and then wet from normal insensible perspiration. And then you will really be cold. So if you wear it, put it close to the skin, and live with the clammy feeling. If you're actively walking, it won't ventilate, and the moisture build up will happen even faster.
Besides that, I don't like the "disposable" aspect. And what's the shelf live in a package? Better off, I think, with the reflective bubble wrap that Susan suggested. That is true survival stuff.
My vote? Not worth the money. Carry a fleece cap and an oversize trash bag instead.
Edited by dougwalkabout (04/03/08 02:04 AM)
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