Inflatable Sleeping Pads: Finding Comfort when Sleeping on the Ground (Updated)

I finally bought a Thermarest NeoAir XLite NXT (had to look up the name of what I bought – jeez), back in March. I bought a regular which is super long and takes up almost all the lengthwise space in my Marmot Tungsten tent. Fits better in my TT Notch Li. My primary sleeping bag is also too long, so at least the toe end rests on the mattress instead of on the floor.

The pad is very comfortable and the 20 inch wide is fine for me (I’m 5’7″ and 160 pounds). As with all my sleeping pads, I put any extra clothes or gear alongside, so if my arms drape off in the night, they land on something that also provides insulation from cold ground. I’m a flip flopper when I sleep, and the mattress is not especially slippery. It really hasn’t bothered me. I am finding that it adds a wee bit more warmth than my old Uberlite, which I loved to death, alas.

I do use a Gossamer Gear thinlight pad underneath. That thing is so useful in so many ways that it’s totally worth the (minimal) weight and bulk. For sitting on rocks at 40F, so much nicer to sit on something that protects against the cold and wet. Sitting on a wet picnic bench, or damp ground, or sand. And of course protection for the inflatable pad. Heck, cut into pieces it might be a good First Aid item too.

I just inflate the Neoair by mouth. It never takes 5 minutes; I can’t imagine why people need 5 minutes to blow up a mattress unless they are physically impaired in some way. Lifelong smoker maybe? Heart issues? Even at 10,000 feet, it’s just not that hard and I’m not a super athlete or anything. If you can hoof it up a 3000 foot climb you can blow up a mattress, no devices needed. Plus deep breathing is good for you. I’ll change my tune if my health declines I’m sure, so no shade on those who need them as an assistive technology! I hate filtering water far more than I dislike inflating my sleeping pad, as far as camp chores go.

So far the mattress is sturdy, but time will tell. I am more careful than I used to be about site selection and clearing sharp rocks. If it fails, I’ll make do and survive.

For pillow creep – I just use a tshirt or a jacket to attach the pillow to the mattress; just slide it over the top as if you were “dressing” the mattress. Might not work for very small people with tiny tshirts.

Unless they have tiny pads.

As a tall side sleeper I am interested in the Sea to Summit Ether Light XR.  I currently use the Exped 3R and was wondering if anyone had thoughts.  Thank you.

Agree with Matt and Roger.  A recent post on Scramble may be of interest and if you see any errors in their thinking let me know and I’ll pass it on to them:

Chasing R-Values, The Malincentive of ASTM FF3340-18
https://scramblekit.uk/review/index.php?id=outdoor&post=sleeping-mats-r-values-and-astm-ff3340-18-malincentives

I think the last section is interesting: “Final Words:  Some Useful Advice From On High” re. High Altitude Alpine Style Sleeping Systems.

Cheers,

Andy

interesting article, thanks – moving body in real world will produce different results so their standard tests aren’t very good

One thing I’ve noticed is that when I measure the temperature of the ground directly under me it can be 20F warmer than the ground elsewhere – the body gradually warms it up – the ground has both thermal insulation and thermal mass.  If you camp on snow or ice the ground will be 32F.

Maybe a better approach would be to instrument a human sleeping over night.  Have temperature sensors on the ground and on the surface of the skin of the human.

Then, maybe you could construct a lab test that produces the same results.  Have a “body” that moves around,…

Then you could compare different sleeping mats.

Maybe you could construct a formula for calculating R value based on thickness, what type of foam or whatever is inside the mattress.  Reflective layers.  etc.  Then you wouldn’t have to test every sleeping pad on the market, but there aren’t that many so you could just test everything on your lab instrument.

For sleeping bags this is worse because there are so many brands of sleeping bags, sizes, different variations – it’s prohibitively expensive for small manufacturers.

Blowing my own trumpet: you could read our own BPL survey:
https://backpackinglight.com/airmat_sotmr_part1_2011/
and
https://backpackinglight.com/airmat_sotmr_part2_2011/

I think the author of the scramble article may have a bit of a bee in his bonnet. He makes a few good points, but also makes many unsupported claims. I will cover a few of them.

* Air movement inside an air mat: full agreement here. An empty airmat can be quite cold. Read the review cited. You need baffles in it, or better still some very light fluffy insulation, to limit air movement Of course, a Down Air Mat (DAM) is the top performer, but the author does not mention them. Yes, I have two.

* His disdain for lab testing seems to be a reaction against something he cannot handle, or perform. He suggests ‘real world testing’, but makes no suggestions as to how you can standardise or calibrate such things. He suggests that testing in a lab will give different results form testing on snow (for instance). Waffle.

* There is no technical reason why snow might make any real difference. In fact, as Jerry points out, sleeping on snow usually results in the snow under you melting, so you are fairly soon on a 0 C surface. In the morning, when we pack everything away in the snow, there is always a depression below where we were sleeping, especially at the hips.

* The author seems to have missed out on the reason many of us have a thin foam mat under our nice comfortable air mat. When you are sleeping on snow, the floor of the tent is going to be at 0 C. Any stray vapour – from your mouth for instance, is going to condense when it hits a 0 C surface. Translation: you will end up with a puddle of water under your mat in the morning. Yes, in general it WILL be water, not ice. I am not worried about my air mat (or my foam mat) sitting on a thin puddle of water, but I am definitely worried that my down quilt might contact the puddle. Fortunately, a wide foam mat, even just 1/8″ thick, will keep the water under it in the depression my body heat makes and away from my down gear.

* The author worries about every one standing around freezing while you blow up your air mat with your mouth. Blimey: who in their right mind blows hot breath (humid air) into their air mat??? The vapour in your breath will immediately condense and fill your air mat with water. Stupid. We use a manual pump for our air mats. In fact, Sue dives in as soon as the tent is up, sits on a small foam mat, and starts pumping, while I am guying out the tent, getting water if available, and so on. By the time I am ready to get into the tent, both air mats will be inflated and Sue will be laying out our quilts (and pillows).

I do agree that some foam is very useful. I kneel on a my little bit of foam when cooking dinner in the tent, We also sit on our little foam mats (sit-upons) for lunch.

Cheers

Thanks for the input Roger.  I’ll certainly pass it on.  But you seem to be confusing the Scramble author with the quoted reddit post re. lab testing.  The Scramble author makes quite clear that he disagrees with the Reddit poster regarding lab testing:

“We agree with many of his concerns (but don’t agree that subjective “real world testing is the best indicator”)” — i.e. the Scramble view is that lab testing is essential, but is simply questioning the current methodology.

Though perhaps Scramble might be better served with a selective edit of that Reddit post.  Very possibly.

Re. blowing up air mats.  Please keep in mind this is a quote from high altitude mountaineers who are talking about small camps at 7500m+ (with no oxygen).  I think the point was more about the redundancy factor of having half your sleeping mat in puncture proof foam.

Isn’t the now melting under your mat, a transfer of heat from the sleeper to the ground?

Thanks for the links, will check them out and pass this info on.   My feeling is that Scramble have given too much emphasis to the Reddit post.  I realise they may have done this in fairness to the author of that post so to not quote out of context, but perhaps that undermines their overall assertion.

Cheers,

Andy

@Roger Caffin

Just so you know, I passed on your post / thoughts to Scramble.  Their editor was very grateful and was considering what to do with that reddit post that was quoted in full.  Since it seemed to cause some confusion, they decided to get rid of it completely and have replaced it with a section on the relation between air and ground temperature (with and without snow coverage).  As they wanted to address the ambient air temperature of the test and the ground plate temperature.  They also discuss the surface area of the side of thick pads.

Scramble asked me to pass on their thanks. The editor also asked me to pass on:

“1) Yes, I do have a bee in my bonnet, and 2) I am absolutely in favour of lab tests that produce sensible results”.

With regard to the High Altitude stuff they disagree, and note that the part of the quote they bolded was:

“Redundancy demands you carry at least half your sleeping mat in puncture-proof foam, so combining that with a small self-inflating (i.e.  foam cored) mat – with the closed cell foam on top”

And that was what they were in agreement with.

Finally Roger, just out of interest, the down mat you referenced – which ones do you use and how many grams do they weigh?

Cheers,

Andy

Hi Andrew

But you seem to be confusing the Scramble author with the quoted reddit post re. lab testing. The Scramble author makes quite clear that he disagrees with the Reddit poster regarding lab testing:
Yeah, my bad there. My apologies to the Scramble author. On the other hand, the Reddit poster seems to fail an IQ test (or maybe just lacks experience).

I would be quite happy to use a good air mat at 7,500 m – over a thin foam mat mind you. Have done so in Nepal. I suspect the problem with air mats is when they come into contact (conflict?) with crampons!

We (wife and I) use Exped Synmats UL7 (450 g) in 3-season, and even sometimes on snow, although on snow we usually have 1/4″ foam mats rather than 1/8″ ones. Sleep OK. Have used these down to -7 C one night – with UL quilts (665 g), although that night we had to snuggle up close and layer the two UL quilts over both of us. That worked fine. Have also used the UL quilts with an overquilt (1075 g) over the two UL quilts. That worked well, and it was the overquilt which collect the frozen condensation. Dried that off at lunchtime in the sun.

For DAMs we have Exped downmat pump SR (626 g) and Mammut Lightpump M (615 g), although we have also used some old Thermarest Deluxe LE mats – self-inflating foam core with good success.

HTH
Cheers

Isn’t the now melting under your mat, a transfer of heat from the sleeper to the ground?
Of course.
But no air mat can stop ALL heat flow, so there will always be some heat going down through the air mat to the ground. You just need to limit that flow.

Cheers

Yes, I meant “snow” not “now”. And thanks Roger for the down mat choices and weights.

Just a final point on the Scramble piece – which in my view, since the major edit, is now a much better article.  They’ve added to section 4 with an example using Exped’s Ultra 3R and Ultra 6.5R:

R-Values are additive. If you have a two mats, each with an R-Value of 1 laid atop oneanother, you will achieve at least an R-Value of 2. Without being too facetious, does this mean if Exped made a 2cm thick mat with no added insulation and only a reflective foil it would have a 3.7 R-Value? Because, in essence, that is what is being added to the Ultra 3R (we’ve just created a mat from the difference between the two) and Exped have leaped from a 3.2 R-Value to a 6.9 R-Value! Further, they tell us it’s good down to -35°C. Yet this bunch of goons on reddit r/ultralight are struggling to keep warm just below freezing. Now, maybe they’re all idiots and don’t know what they’re doing, but just a glance at the specs would suggest the ASTM testing protocol is very impressed with an extra 2cm and some reflective foil. There’s a review of this pad here, where the reviewer started feeling the cold below -5°C.

It’s certainly an interesting topic and I’m sure many will have much more to add.

Thanks to all at BPL for encouraging such debates and promoting more lab-centric testing. On that issue I know I and Scramble wholeheartedly agree.

All the best,

Andy

Yet this bunch of goons on reddit r/ultralight are struggling to keep warm just below freezing
Indicative perhaps of a lack of skill or experience maybe?

maybe they’re all idiots and don’t know what they’re doing
On Reddit? Who’d a thought?
But that is the Internet.

The extra 2 cm is big. Adding a reflective layer could also be very good.
I have no links to Exped, but we are very happy with their mats.

Cheers

Saying that a pad is good down to -35 or whatever is confusing.  It depends on what else you’re wearing.  You could have a warmer sleeping bag and a cooler pad or vice versa.

Or you could be comparing conditions under an elevated mini-tarp with those inside a double-skin tunnel with the windward end closed – when there is a 60 km/h wind blowing past.
Cheers

Yes, all fair points.

Just to be clear,  Scramble like Exped also,  2 of the pads they’re experimenting with are made by Exped.  And in that piece, in relation to air pads, they recommend Exped, Thermarest, etc…

In fact, my feeling is they tend to be harsher on claims by brands they actually like.

Andy

“Saying that a pad is good down to -35 or whatever is confusing.”

+1 to that, Jerry.

I personally believe it doesn’t just create consumer confusion but is irresponsible.

A sleeping pad is one part of a larger thermal system, and it’s disingenuous for pad manufacturers to claim their pad “is good for -35 degrees”. Fortunately, the writers over at Scramble clearly see right through this due to their comment about Siberia.

Unlike the sleeping bag tests (which are more assembly based), the industry must recognize that ASTM F3340 is merely a materials based test, and must stop promoting it beyond it’s purpose. Even in Roger’s 2011 market report, he clearly pointed out that fully understanding mattress performance would require systems level testing, not just materials testing.

As an architect, I would never suggest to a client that their home’s habitable operating temperature can be determined simply from the R-value of a single material. Specifying ccf in lieu of fiberglass batt in a wall or roof assembly might eventually contribute to greater energy efficiency, but it takes specifying the whole assembly, and dependable testing of the entire building’s performance before one could claim that the home is be suitable for a given climate.

ASTM F3340 is great at what it is attempting to measure: “one-dimensional” steady-state thermal resistance in a controlled lab setting. It’s actually not all that different from ASTM C518 in the building industry. But striking up a conversation with my work’s AI agent this morning, it quickly outlined 8-10 unique materials tests,  5-8 different assembly level tests, and 5-7 building performance tests.

At least ISO 23537 tries to consider the entire system to offer reliable comfort ranges for a sleeping bag. I think it’s high time for the industry to create systems level testing for mattresses. That way consumers may finally to understand why every winter camping expert recommends ccf, and get to the bottom of the the actual physics behind adding ccf on top of (or underneath of) an air mattress, instead of relying simply on anecdotal experience.