Compressible / packable under-pad layer to increase R-value?

[BillyBob58]

Did Hennessy ever change to the breathable radiant reflective material, as he was talking about a few years back? I believe the material was from the S.O.L. Escape Bivvy and he was seeking to source the material from them.

Trying to remember. He switched to a breathable under cover, with (I think) the non breathable space blanket added outside of the pad(between pad and UC, rather than between hammock and pad) He said that if condensation occurred, it stayed on the out side of the pad, which would quickly dry and/or if frozen, could be brushed off the next morning. This was called the "Insulated Hammock" I think. Personally, I preferred the original system with a sil nylon outer shell, then the pad, the the space blanket. Worked flawlessly for me for years. And wind proof/water proof.

[cmc4free]

Good insights Bill. As I mentioned before, I don't have any experience with the HHSS, but personally don't have any problem adding some sort of vapor barrier to my systems when called for. I think you would agree.

[cmc4free]

And btw, I remembered where I heard him discussing the breathable radiant reflective material. It was in his interview on one of the early episodes of the HYOH podcast. Worth a listen, to hear some firsthand stories from one of the real pioneers of modern jungle hammocks.

[BillyBob58]

Good insights Bill. As I mentioned before, I don't have any experience with the HHSS, but personally don't have any problem adding some sort of vapor barrier to my systems when called for. I think you would agree.

Yes I would. BTW, as far as I know or remember, the space blanket he was using in the new "insulated hammock" was still using the same not breathable space blanket as the original HHSS. He had simply switched to a breathable outer layer and did not use the space blanket unless temps demanded. In which case he then moves the space blanket to the other side of the pad. What I didn't like was: even though he was using the same space blanket, he had lost the wind proof, water proof outer layer that made that thing so bombproof. At least for the folks who used it correctly and as designed. I think I did read some folks who said it was still warmer with the space blanket on top of the pad. I'm just guessing, but I think he was giving in to demand for breathable systems. Last I checked, he still sold the old system.

EDIT: The newer system is not called "insulated hammock" but rather "4 Season Hammock". :With just the oversize open cell foam pad, most people are comfortable down to about 40 F / 4 C. Adding the space blanket under the pad should take you down to below freezing. The space blanket can be placed above or below the pad depending on the temperature, humidity and what works best for you................The 4Season Expedition also includes an oversized 30" / 76cm wide open-cell foam pad, and a heat-reflecting space blanket."

[cmc4free]

Same here, I looked around and there's no mention anywhere of them "upgrading" the space blanket material. IIRC, in his interview he was talking about trying to work a deal with S.O.L. to buy the material, and perhaps that never came to fruition.

If it's actually a DuPont (Tyvek) product, I would think he'd have had other avenues to obtain it.
https://www.dupont.co.uk/products/tyvek-reflex.html

Maybe they tried and decided it didn't work as well, or didn't offer enough improvement to justify a (presumable) cost increase over normal reflective mylar. If it ain't broke....

Edit to add:
https://www.hammockforums.net/forum/...=1#post1944951

[Happy]

Edit to add:
https://www.hammockforums.net/forum/...=1#post1944951

This is some great info. I imagine there are a number of manufacturers of reflective, breathable fabric now that it's becoming more common in jackets etc. Some that are more suited for this purpose than the Tyvek.