Best lightweight Sleeping Pad for Winter Alpine Climbing

Dave Schultz wrote:The surface of the snow is rarely 32 degrees, and almost always colder. The surface temp is a function of the air temp, and to a much lesser degree a function of the solar energy from the sun. The ground, below all the snow, will likely be around 32 degrees, but again, not always the case.

All true but it neglects to consider the effect of the person.

Jesse Toedtman wrote:Not trying to argue just curious the science behind the ground always being near 32*f? I would think it could be much colder than 32*?

Snow is an excellent insulator though it will stubbornly refuse to go above freezing. Your body will quickly heat up the sleeping mat and in turn the layers below your sleeping mat including the snow. The snow immediately below the sleeping mat will raise in temperature until it reaches 32F. Thus it is correct to say that the snow under the sleeper will be 32F.

Of course if you have an EXCELLENT mat then this may not be the case, but everytime I've slept in snow I've found a nice mat shaped indentation of melted snow underneath my tent/bivy. That is clear evidence that the snow underneath was 32F.

I once slept on a wooden balcony while trying to acclimatize to temperatures well below freezing. I could feel the heat being sapped out my back despite having TWO mats. With the air temp below -10F passing under my mat, it was damn cold. (My sleeping bag was lofting ~8 inches so was plenty warm.)

climbing2man wrote:I'm looking for people's opinions of what I should purchase for the best winter mountaineering sleeping pad. Looking for a temperature rating around 15' F. Also looking for something that packs down small and is lightweight.

I'd either go with the Therm-a-Rest NeoAir XTherm in a regular size (15 oz, 1.6 L, 5.7 R), OR a Therm-a-Rest NeoAir XLite Women's (12oz, 1.4L, 3.9 R).

The small sizes of these pads will save you a couple ounces, but most people enjoy the extra length. Another problem with the small size of the NeoAir pads is that they tend to taper too much at the bottom. This is a bit too aggressive for me. I have a ⅔ length original, rectangular NeoAir that I love. In winter I couple it with a cheap ¾ length blue foam pad that I got from Walmart for $5 and taped it into an accordion style type pad. The blue foam pad replaces the back panel in my pack saving weight.

The Big Agnes Q Core SL is a fantastic pad as well, but I'd opt for the NeoAir series pads I mentioned just to save a few ounces. The Q Core is less noisy, but has slight side rails that some people find uncomfortable. In contract, the NeoAir pad edges are fragile when the pad is under inflated.

15ºF ambient temperature isn't as important as the surface you're sleeping on. Rock and ice can conduct heat many many times faster than dry snow.

With any of the pads you choose, you'll get the maximum amount of heat the more you inflate it.

Here are some resources that I like on this topic:
backpackinglight.com/airmat…
backpackinglight.com/airmat…
backpackinglight.com/forums…
backpackingengineer.com/eng…
bpbasecamp.freeforums.net
And finally outdoorgearlab.com/Sleeping…

- Jeremy

patto wrote: All true but it neglects to consider the effect of the person. Snow is an excellent insulator though it will stubbornly refuse to go above freezing. Your body will quickly heat up the sleeping mat and in turn the layers below your sleeping mat including the snow. The snow immediately below the sleeping mat will raise in temperature until it reaches 32F. Thus it is correct to say that the snow under the sleeper will be 32F. Of course if you have an EXCELLENT mat then this may not be the case, but everytime I've slept in snow I've found a nice mat shaped indentation of melted snow underneath my tent/bivy. That is clear evidence that the snow underneath was 32F. I once slept on a wooden balcony while trying to acclimatize to temperatures well below freezing. I could feel the heat being sapped out my back despite having TWO mats. With the air temp below -10F passing under my mat, it was damn cold. (My sleeping bag was lofting ~8 inches so was plenty warm.)

Really good information.

I have slept in a hammock before and found it to be FREEZING.

Dave Schultz wrote:Interesting. I see how that can be a pretty good argument, thanks for clarifying what was meant by the original comment.

That is not how this forum works! We are supposed to continue to disagree in a heated debate! :p

Not problems for the clarification. I initially agreed with your comments, but then I though about it for a bit longer and realised....

Jesse Toedtman wrote: Really good information. I have slept in a hammock before and found it to be FREEZING.

Yes, I was meaning to mention that. Having a good mat is super important in a hammock if the air temperatures are cold. ~40% of your surface area is you back and you sleeping bag does next to nothing for you back if you are compressing it.

Oh and while we are talking about thermodynamics. Don't underestimate the coldness of a clear night sky. The different in heat loss between bivvying on a ridge line vs a cave or a valley is huge. Even tree shade helps alot in keeping you warm on a clear night.

Even if air temperatures are above freezing, surface temperatures can easily fall well below freezing.

patto wrote:Oh and while we are talking about thermodynamics. Don't underestimate the coldness of a clear night sky. The different in heat loss between bivvying on a ridge line vs a cave or a valley is huge. Even tree shade helps alot in keeping you warm on a clear night. Even if air temperatures are above freezing, surface temperatures can easily fall well below freezing.

Patto,

That's a really great point! Thanks for sharing, this isn't something that I think about too much.

Don't know shit about winter climbing but i enjoy a good nights sleep.

To add another option to the mix:

Could mix a thin closed cell with an xtherm. Can use the closed cell on the bottom on sharp ground, and if you do pop the xtherm you're not completely lacking in insulation. For some reason its more comfortable / warmer with closed cell on top.

I've found around 15f that I'm a bit cold with just an xtherm (the orginal) alone.

It is a bit more faff.

These guys sell 1/8" and 1/4" foam, as well as egg shell pattern.
gossamergear.com/sleeping.html

Another vote for an NeoAir XTherm. I've had mine for 3 years or so now, it finally got a hole in it this past summer. Easy repair in the field with a little bit seam seal.

As others have mentioned, air mats fail, always have a way to repair it in the field. A tube of seam seal and some cloth tape have fixed every air mattress I've ever had. On long trips they are worth the extra weight.

Charlie S wrote:Insulated Static V also comes in a "V lite" option

Yeah I saw that and called Klymit, and they admitted they cut some weight by using less insulation inside. Couple that with a less durable bottom, and I went with the original.

For those looking for a thin and durable CCF to compliment their inflatable, check to see if any of your friends put down new hardwood floors and steal some of their underlayment. The right stuff can be quite puncture resistant even for ~1/8"

James T wrote:For those looking for a thin and durable CCF to compliment their inflatable, check to see if any of your friends put down new hardwood floors and steal some of their underlayment. The right stuff can be quite puncture resistant even for ~1/8"

That's a great idea. Maybe I can finally "clear" out my garage of those leftovers!

patto wrote: All true but it neglects to consider the effect of the person. Snow is an excellent insulator though it will stubbornly refuse to go above freezing. Your body will quickly heat up the sleeping mat and in turn the layers below your sleeping mat including the snow. The snow immediately below the sleeping mat will raise in temperature until it reaches 32F. Thus it is correct to say that the snow under the sleeper will be 32F. Of course if you have an EXCELLENT mat then this may not be the case, but everytime I've slept in snow I've found a nice mat shaped indentation of melted snow underneath my tent/bivy. That is clear evidence that the snow underneath was 32F.

Thank you, Patto. I was not was aware that this wasn't common knowledge to experienced winter campers.

It's been mentioned, and I'll add my vote - sleeping in a hammock, rocks, wooden structures - the ground can get much colder. As suggested, adding a closed cell mat under your inflatable is a light, but bulky way to increase thermal efficiency. From personal experience, even a good insulated inflatable in a hammock only slows heat loss a little. Plus, inflatables are awkward in a standard hammock because they tend to pop out from under you like a bubble.

While people are discussing hammocks, I'll pitch in and say that pads aren't the best way to go there. An underquilt is truly the best option but requires significant investment $$. That said my hammock is very warm to 0 degrees with a HammockGear UQ and TQ.

Back to pads.... I like solid foam Z-lite with 3 season inflatable because it utilises the inflatable I use the rest of the year and adds redundancy. Probably would buy something better if I did more winter excursions.