R value

[hikergurl]

Silly question, but does a windshield reflector pad thingy have a known R value that someone is willing to share? I know most of the "warmth" is reflecting radiant heat, but what about the 1/8ish" foam material? Thanks

[Razor]

I used one last year for most of the season. I can not tell you the emperical value except it works on the warmth actor .I am not using it this year because I slipped off and was hardly on it except in a shelter. On not level ground where I needed it the most, I rolled off it and was very hard to control after you are in your bag!

[rocketsocks]

Silly question, but does a windshield reflector pad thingy have a known R value that someone is willing to share? I know most of the "warmth" is reflecting radiant heat, but what about the 1/8ish" foam material? ThanksHey Gurl,Not only have I never heard of this,but that's a damn fine Idea and just what I was looking for too.Was considering using survival blanket and a thin foam mat to further my uninsulated BA air core.Thankey:)

[hikergurl]

Hi Socks, you're welcome but the idea isn't original to me. You can look at similar ones out there from Hennessy Hammock's website and from Sgt. Rock's website (shameless plug, Sarge, hope you don't mind). What I ended up doing was trimming the part from my waist down to a taper so that it's about a foot and a half wide at my feet, then using the scraps to fill in the cutout for the rear view mirror. Used aluminum tape to seal it all off (hint: watch how you trim the tape on the corners, if it's too sharp, it can snag). Hennessy has a beefier version (and I think a couple other places do, too) that is double laminate, thus, a bit warmer. Fair warning, on the homemade version you have to get used to the..."crunchiness" of the pad, unless you add another layer to muffle it, like a thin fleece, which will also add a smidge more warmth. I bet if you add the thin pad you're talking about to the windshield reflector you'd have a fine sleeping pad.

The other option I was thinking about, too, but not yet brave enough to try is trimming the windshield reflector narrow enough to fit inside with me in the sleeping bag, like half a vapor barrier liner. If anyone has tried this to any level of success I'd like to hear about it.

[JAK]

Interesting idea of using it inside your sleeping bag. I don't think it would work well with a down sleeping bag because it would just compress the expensive insulation everywhere rather than just at your pressure points. If you want to go that route it would be better to use a quilt integrated with a sleeping pad, or at least a sleeping bag that has more insulation on top and less underneath. How much pad insulation you need versus top insulation depends on ground temperature versus air temperature. Also, whether the ground has any inherent insulation value. Snow can be very effective when its really cold, because it effectively sets the ground temperature to a more or less constant 32F, even if the air is -20F. In that scenario the ground pad would only need about half the insulation value of your sleeping bag or quilt. Dry ground and forest litter can be even more effective, especially under trees that raise the ground temperature underneath them, by storing daytime heat into their root system, and sheltering the ground from radiant heat loss at night, and precipation that has potential to reduce ground temperature. If you pick your ground carefully your ground pad can be more minimal, but you can be in for a shock if you get stuck for the night on an exposed mountain top. Some sort of pad is always wise, even in summer.

I think simple blue foam pads are pretty versatile. I like wool blankets and light ground sheets for dayhikes. Less bulky and more veratile, though heavier.