Topic
Become a member to post in the forums.
I was thinking about the possibility of having some air within a bag to add insulation and loft. Has anyone ever heard of this?
Essentially a bag that has a sealed inner layer you could add a little air to. Not totally inflate so its stiff, but just enough to add some additional (.5-2"?) space between you and outside.
Has this been done? What are your thoughts on it?
I have thought of this too. There are some problems that would make this not very easy:
1. To seal air, it would have to be unbreathable (obviously). You would have to deal with all the problems of a vapor barrier layer or make open sections to allow vapor to pass between baffles
2. The fabric would have to be heavier than fabric typically used in sleeping bags. You may not be laying on your bag all night like you do with a mat, but it does have to be able to hold up to someone sitting on it. And it has to be puncture resistant enough that you don't pop it with normal use.
3. You have to deal with convective currents. Convective currents are stronger with insulation above you (sleeping bag) and insulation underneath you (air mat). We know how important it is to deal with convective currents below you. It would be much more important in a sleeping bag. You would have to keep baffles very narrow or put material inside to prevent convective mixing. One of the warmest ways they do this in mats is to fill it with down. If your going to fill it with down… you might as well get a sleeping bag.
In the end it is going to be very challenging to get a better (lighter) product than the bags on the market. In theory it would work, because you are using air to volume in your insulation instead of down. In practice it is going to be pretty hard to beat existing products.
A wide Downmat UL7 is 25" wide and weighs 30 oz with an R of 5.9
A slim EE Revelation is 50" wide narrowing to 38" and 0° bag only weighs 23.7 oz with their lowest quality down.I'm not sure what the total length of the quilt is, but I bet the short is pretty close in length to the down mat.
The EE quilt is much larger surface area and probably provides better insulation for less weight.
this thread reminded me of something i saw in the early 90's, i thought it was developed in upstate ny
here is a canadian test report
http://www.dtic.mil/dtic/tr/fulltext/u2/a257809.pdf
Become a member to post in the forums.
advertisement
Discover under-the-radar ultralight gear from small brands.
© Beartooth Media Group Inc.
Loading...
