I suppose you talk about the Exped Syn Mat UL7; indeed there shouldn’t be much difference having the CCF on top of below IF you’re using an airmat WITH some kind of filling, because the filling should stop (or at least reduce) the convective heat loss. Whether this filling is down or synthetic is irrelevant -- well, in reality it isn’t because down would be better but.... that’s not the point I’m making. I’d like to know whether it could be important when using a full length, plain air core mat (without fillings).
Copy/paste from my second post on this matter: >”So...... I’m about to buy a full length, plain air core mat to give me the comfort I need (as I’m getting older, it won’t get any better) and boost the insulation with a CCF (or even two, like Mike suggests --- making a sandwich).”<
Under normal circumstances (3 season-use) I’d definitely put the CCF below to offer puncture protection (as you say). My quest is really about what to do in winter (on snow) when my mayor concern becomes the thermal insulation and, at the same time, I’m not that worried about punctures.
Thanks for your suggestion. It’s more or less the same as what Mike came up with in the first answer on my initial question (sandwich the inflatable between 2 layers of CCF pads -- the top one with a sufficient, appropriate R-value). To be honest.... as I haven’t received any *scientific* answer on my question about what will be better in terms of thermal insulation, the *sandwich* idea is what I’m pondering right now.
Since nobody came up with a clear answer, I suppose I’ll be wrong in assuming there should be a difference in between having the CCF on top or below. Having said so...... I understand that, theoretically, the R-values are accumulative but I can’t believe that, having the inflatable on top, with my body tossing und turning all night and therefore stirring up the air inside the inflatable, that this won’t have any influence on the relative warmth the inflatable could/should provide to my body (in reality, since the air inside the airmat will be colder, it will be robbing heat from my body -all night-). On the other hand, if I put the CCF on top, I do believe (maybe/possibly I’m wrong) that, no matter how much I move during the night, there won’t be any convective heat loss BECAUSE this CCF consists of thousands of tiny little bubbles that are not connected with each other. Furthermore, once I can heat up the upper part of the CCF (spending a lot of energy, precious calories, in doing so) it will stay warm at the moment each and every bubble has reached its thermal equilibrium in relation to the bubble *next door* (at least that’s what I think).
Once again, I really think that this subject is of importance (at least to some degree) because IF position matters, one could get away with a thinner (lighter) mat if same would be positioned right. And this would make it possible to REDUCE our overall pack weight.