I have been thinking about the downs in the air mattress:
In order to prevent the down from leaving your mattress when you deflate it, you'd want to install some kind of a 'net' on the inside of the valve. probably an inch or two away from the valve in order to increase the net’s surface area.
However, when storing the mat at home inbetween your trips, the air tight mattress is not a good place to keep the downs. It is too constricted and they have no way to ‘breath’ which downs should. Thus, i think it is best to somehow make that net mentioned above removable. In this way you could remove the net and then let let all the down out and keep them in a better siuted place inbetween backpacking trips. Letting them out should be fairly easy, just by deflating it most of them should exit. And if you deflate the mat’s air along with the downs into a proper nylon bag right away, it should not be too messy (i.e. not loosing too many downs). Also, you’d want to take a very tight woven nylon bag for this with avery small opening preferably one that you can ‘attach’ to the valve of your mat. In this way, when you want your downs back in your mat, you can just attach the storing bag’s valve to the deflated mat’s valve, open the valves and pump up the valve with the storing bag. (in order to make this work, the nylon of the storing bag needs to be woven tightly enough to use it as a pumping bag, yet breathable, else you had gained nothing.)
The Problem is i’m not too sure as how to install that removable net in the mattresses valve. What are you guys thinking about this?
Another concern: has anyone tested the mat with a radiation barrier (solar blankt or space blanket) in order to increase the mat’s r-value (clo)? In the NB fugu jacket this seems to be working quite well. And is thermarest’s neoair not having one of those radiation barriers as well?