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Aluminum or Mylar Sleeping Pad for Snow

PostPosted: Wed Nov 17, 2010 9:16 pm
by showlett
Our Shasta guides had short sleeping pads that had a reflective surface, and I was told had a higher insulation value than regular sleeping pads. I thought they said they were Mylar, and that I could get the material at Home Depot. I did find some rolls of reflective insulation (Reflectix) that is made of layers of aluminum and insulation. It looked like what they had, but I'm not sure. Do they sell anything like this for mountaineering? They were using these in combination with traditional sleeping pads.

Re: Aluminum or Mylar Sleeping Pad for Snow

PostPosted: Thu Nov 18, 2010 1:35 am
by bearbreeder
reflectix pads dont work any better than a thermalite , you can do a google search for the explanations and numbers

now the ridge rest solar is a different story ...

Re: Aluminum or Mylar Sleeping Pad for Snow

PostPosted: Thu Nov 18, 2010 2:04 am
by MoapaPk
bearbreeder wrote:reflectix pads dont work any better than a thermalite , you can do a google search for the explanations and numbers

now the ridge rest solar is a different story ...


Tell us more! I have a ridge rest that is at least 16 years old; it's my only backpacking pad. It still seems fine, and the new ridge rest pads seems to be exactly the same weight. But I'm heading to colder weather...

Re: Aluminum or Mylar Sleeping Pad for Snow

PostPosted: Thu Nov 18, 2010 2:31 am
by showlett
bearbreeder wrote:reflectix pads dont work any better than a thermalite , you can do a google search for the explanations and numbers

now the ridge rest solar is a different story ...


I don't know about that. The google searches I did say the Ridge Rest Solar has an "R" value of 3.5, compared to the R-15 rating of the reflectix material I found in Home Depot. There must be a reason these guides who practically live on the mountain are using it!

Re: Aluminum or Mylar Sleeping Pad for Snow

PostPosted: Thu Nov 18, 2010 4:05 am
by bearbreeder
showlett ... the R value for reflectix is as a radiative barrier ... which means there's an air gap such as in an attic or similar ... for a surface to surface the R value is 1.1 according to their literature, measured values that you can find show around 0.67, so your guess is as good as mine .. a cheapo foam pad will give you an R value of roughly 1.3-1.5 ... the zlite has an R value of ~2 ... ive never seen a guide use reflectix .. lol

MoapaPk ... the radiant barrier on the new solar ridge rests supposedly boost the R value to 3.5 which is much more than a normal RR at 2.6 ... they are a tad heavier than the however anecdotal reports show that quite a few of them are actually lighter than the factory weight ... id say that your bivy torso pad from yr alpine pack and a RR Solar should get you through a lot of alpine stuff at a decent weight ... note that cascade designs tested their neo air to ASTM International standards, i assume they do the same with the solar ... at least you know what yr getting meets spec ...

Re: Aluminum or Mylar Sleeping Pad for Snow

PostPosted: Thu Nov 18, 2010 2:53 pm
by rhyang
showlett wrote:There must be a reason these guides who practically live on the mountain are using it!


Probably because it's cheap :)

Reflectix does have other uses .. I've made insulated cozies for pots and cups and such out of the stuff (hardware stores also sell aluminized tape for joining seams). Bear in mind that it's basically bubble wrap. Ever play with bubble wrap and pop the bubbles ?

I don't doubt that during the summer it might work just fine for short trips. And being cheap it is easily replaced, unlike an $80 thermarest prolite plus or some such.

Re: Aluminum or Mylar Sleeping Pad for Snow

PostPosted: Thu Nov 18, 2010 6:40 pm
by Buz Groshong
rhyang wrote:
showlett wrote:There must be a reason these guides who practically live on the mountain are using it!


Probably because it's cheap :)

Reflectix does have other uses .. I've made insulated cozies for pots and cups and such out of the stuff (hardware stores also sell aluminized tape for joining seams). Bear in mind that it's basically bubble wrap. Ever play with bubble wrap and pop the bubbles ?

I don't doubt that during the summer it might work just fine for short trips. And being cheap it is easily replaced, unlike an $80 thermarest prolite plus or some such.


It probably doesn't hold up as well on airplanes and at altitude though.

Re: Aluminum or Mylar Sleeping Pad for Snow

PostPosted: Thu Nov 18, 2010 8:48 pm
by bearbreeder
lol ... reflextix wasnt any cheaper than the blue foamie at wallymart last i checked

i think a lot of people get hung up on the R-value of 15 ... which wont occur in an alpine situation

from their own website ...

Image

if you do the math ... youll note that the reflectix provides the least efficiency of any commonly available pads per oz/yd/whatever ...

the reflectix is listed as 1.25 oz/ ft2 ... so 11.25 oz/ yd 2 ... for an R value of 1.1 if we accept the manuf claim ... which is an R per oz/yd of 0.097

the mec blue standard 9.25 oz / yd if my math is correct ... for an R value of 1.36 .. R per oz/yd of 0.146

the mec yellow standard 13.75 oz / yd if my math is correct ... for an R value of 1.6 .. R per oz/yd of 0.116

the yellow thermalest zlite is 12.93 oz / yd 2 ... for an R value of 2.2 ... giving and R per oz/yd of 0.17

the RR Solar is 17 oz / yd 2 ... for an R value of 3.6 ... giving and R per oz/yd of 0.21

Re: Aluminum or Mylar Sleeping Pad for Snow

PostPosted: Fri Nov 19, 2010 3:18 pm
by rhyang
I wonder if the guide service has a big roll of the stuff they bought in bulk. Makes sense to use something cheap for dragging clients up the same hill every week, and save the wear & tear on your good sleeping pad for real trips :)