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Windbelt powered heated jacket Answered

Hi everyone. After reading about windbelt and looking at prototypes designed by some folks here I have got an idea. Basically use windbelt to recharge a battery -I believe li-ion polymer battery is the lightest. The battery in turn can be used to heat a jacket. Idea is to use carbon microfiber sheets which heat up when electric charge is supplied by the battery. A battery wont last long so it is important to focus heating the core- heart and lungs. If these parts are very warm that the body will divert heat to warm other parts. If you are an ultra light hiker or a racer and travel in cold windy places you will understand how cool this thing would be. Down/synthetic insulation is bulky -Now just imagine the bulk of warm sleeping pad and down/synthetic insulation gone from your pack.. This could be a possible future. Anyone interested?


I like that idea, if you can get it to work. I probably woulnd't use or trust it out in backcoutry, but you would be amazed how many times I have wished for a heated jacket on my bike. One time I even considered taking an electric blanket and having it sewn into my winter leathers and then adapting it to plug into the bike's electricals. But if it were possible to make it work so that the wind generated by going down the highway powered that jacket which kept me warm, that would be invaluable. Maybe not a replacement for down when backpacking or climbing, but I would go to the trouble of wrestling with my arch nemesis--electricity--if it meant I could build a jacket that meant I didn't have to wear a sweater and possibly a down jacket under my leathers. By all means, experiment. I'd love to hear how it goes!


10 years ago

Still the domain of SciFi...

--Down is not bulky, for sleeping, anyway. In fact, high-quality down (700+) compresses much better than any synthetic insulation. It's very small in a pack.

You want magic? Consider that a 4 or 5 lb. down bag works to -30 degrees F or lower (if you wear more clothing, also.) All with excess body heat. For weeks or even months without refueling (the bag, anyway--you need refueling.)

And a down sleeping bag won't fail-- if you keep it dry (not an issue at high-altitude, where humidity is extremely low.) I sure wouldn't trust my life to a single electrical device.

--Some electrically-heated jackets exist. I believe they work for 3 or 4 hours per battery. I can't image anything short of a medium-size solar panel would charge the batteries in a day (for one person.) If it were sunny...

I could see the value of such a jacket when standing at a belay or something for a long time (I one belayed a guy for three hours in the shade, on a 10 degree day..ouch.) Or on an unforeseen bivouac--then the one-shot nature of the battery could get you through the night.

When you're moving, venting heat is usually more important.

--Until the "magic power supply" is realized, the weight, bulk, complexity of an electrical solution is...um, no solution. Yes, This could be a possible future, but it's a cold-fusion, flying-car future...

Thank you for the comment. I understand thatyou like most people dont want to trust electronics in backcountry. But as you said -4 or 5 lb. down bag works to -30 degrees F- thats heavy! My goal is NOT to go without insulation. Ideas is to wear adequate insulation required while moving at moderate pace and use a heated jacket in place of extra insulation you would need when sleeping. The idea is to heat the core- heart and lungs. So body diverts its heat instead to warm other parts. I will still carry additional insulation for head, hands and foot.

I don't want to discourage any experimentation, but I doubt that the complete system (electric clothing, battery and charger) will be less than 5 lbs. Plus we've neglected the bulkiest item of all (although not the heaviest)--the sleeping pad. No matter what the efficiency of the sleeping bag, no one goes without a pad--you loose too much heat through conduction with the ground or snow. A pad weighs anywhere from a bit over 1 lb to about 2.5 lbs (it's worth every oz.) Many people carry two--an inflatable open-cell for comfort, and a lighter closed-cell for greater insulation. Synthetic bags don't compress beneath you as much as down, so you can get by with one pad in that case. I've got 5 different pads of varying type and weight, depending on the trip... Again--run with it, but I have my doubts....

I doubt that the complete system (electric clothing, battery and charger) will be MORE than 5 lbs. But what I realised is that unless I have some super light high capacity battery which will warm my entire body and some really efficient way to to charge that battery on trail I will be carrying a sleeping pad which makes the whole setup heavier then other ideas im playing with.

I can see your point. I have some ideas for super light insulation. one is to make sleeping bag with inflatable poly bottom so down doesnt get compressed by your weight. Or use a Down Air pad made using poly with a topbag which is basically the same thing. Using 850+down and silk as light as 0.57 oz/sq yard you can make insulation really light.

. Sounds like a great idea. . I see two possible problems. If the 'carbon microfiber sheets' don't breathe, this could be very uncomfortable. The weight of a battery with enough capacity may be more than acceptable (sounds like you're already aware of this). . Would you use the windbelt only when stationary, or do you plan on charging while running? . From what I've read (I may be wrong), windbelts don't put out a lot of current, so charging times are liable to be quite long. . Make sure everything is sweat-proof. :)

Nacho, thanks for the comment. your first concern is answered. Li-ion polymer batteries are expensive but very light. These batteries are used in mobile phones and laptops. >Would you use the windbelt only when stationary, or do you plan on charging while running? I have several ideas in mind: 1)A wind belt can be strapped to each arm -from shoulder end to elbow. I read a comment here by the inventor, Shawn Frayne that he has succeeded in making small windbelts really silent. 2)Another idea is to attach windbelt on each side of a backpack. 3)Also it may be possible to use trekking poles as a support for a larger stationary windbelt. Hopefully I or someone else will eventually figure it out. Shawn Frayne said he hasnt yet figured out how to make larger windbelts silent. Well I can always use a pair of earplugs. >. From what I've read (I may be wrong), windbelts don't put out a lot of current, so charging times are liable to be quite long. May be with several windbelts enough current can be produce to reduce charging time. >Make sure everything is sweat-proof. :) I expect voltage will be less than 12V -so its impossible to be electrocuted.

> hasnt yet figured out how to make larger windbelts silent . Unless you keep the vibration of the belt below ~20Hz or above ~20KHz, I don't see how it would be possible to make one silent. The belt is, in effect, a skinny speaker diaphragm. . > less than 12V -so its impossible to be electrocuted . Not impossible, but unlikely. I'd be more concerned with shorts (burn hazard) and corrosion of the electronics and wiring.

I would suspect the carbon microfibers to be quite breathable, as long as they aren't super tight weave... I think a light weight flexible solar panel would hold more benefits for when moving etc. If you were on a bike and travelling in the cold it could be easy enough to generate power. There are projects on using the expansion and compression of your chest as a source of power for a gnerator based on small servo motors. A similar generator could be made using the energy create while walking. This sounds like a cool idea, granted it would be difficult due to the amount of power needed to make the heat, also peltiers could be considered though they may or may not be more efficient than direct resistance heating.

Thanks for the comment. You are right. A loose weave will be breathable. Flexible solar panel cap and backpack lid was my original idea but I realised that I would rather trust wind then the sun. (ok I trust the sun but I dont trust the clouds) Now something that extracts energy from your the friction under your shoes would be interesting.

Errr that would be bad since it would involve losing some friction... Well solar panel would be a viable answer since they don't need perfect clear days to operate and can be pretty efficient now, as well as being at a high altitude, if you're up a mountain above the cloudline it's not a bother. Of course on another solar path you could use a heat excahnger similar to the hot water systems which may be a more efficient design.

I will think about solar panels. btw do you know of anything that can convert infrared into electricity?

I have no idea if photovoltaic cells take advantage of the whole light spectrum or not...

As long as you don't have to wear the windbelts! Imagine walking through the countryside as the wind blew through the belts;


That would be funny on a bike... I still suspect for people sized transport a solar panel would be good...