NeoAir Xtherm for snow camping- Is it really warmer

I would say that the test is not necessarily valid to compare the absolute warmth of both pads. CCF pad + an inflatable with R-value of 3 should result in a total R-value of about 5. That’s plenty warm for most people down to about 0*F. I think you’d have to drive it into much lower temps. If you did, I bet there’d be a point where the X-therm is still sufficient and the X-lite is not.

Actually at 15 to 20 degrees F, I was not warm on top of the Xtherm even with a Zrest underneath it. I had to double up the Zrest and put my sit pad underneath my torso just to make it through the night.

Has anyone actually tested the R value difference between the two products?  I almost felt like the Xtherm was radiating and losing heat out of the four sides.

Few people are going to have the resources to literally test the R value, which is  a standardized laboratory test with many technical protocols.

However, the last day of last winter (March 2015) a friend and I camped on top of Slide Mountain in the Catskills (NY). The temperature got down close to zero, although 4°F when we tucked in, but it was dropping still, and then rose to 12°F by morning with the arrival of a front. My friend was using an Xtherm (long) and I was using a Neoair Trekker torso/wide (47″x25″) with my pack under my legs/feet, and with a 3/8″ CCF pad on top, with an EE Enigma 20 quilt and wearing down parka and pants, as I always do to achieve a lighter sleep system weight. Under his X-Therm the following morning there was significant melting of the snow, indicating lots of heat loss, while under my airmat/CCF combo there was extremely little melting of snow. I was warm all night, and my friend told me he was warm as well, but in my experience if I had that much melting under my sleep pad it would almost certainly mean I had a fitful, cold night, with sleep frequently interrupted.

There are a couple of other threads now ongoing that are dealing with this topic (one off-topic and one on-topic), but from what I’ve seen and experienced over the years I would say that sleeping pad system effectiveness cannot be measured simply by doing the math and adding up the R numbers.

One thing I am certain about is that for my system it is better to have the CCF pad on top. This winter has been a bust regards to winter gear testing, but last year we had wonderfully consistent snow and cold and I was able to test and tweak quite a bit. During the course of one night I was able to sleep with the CCF pad on the bottom for a few hours and then switch it to the top, and there is zero doubt in my mind that CCF on top is better… at least for my system.

“Has anyone actually tested the R value difference between the two products?”

Presumably that’s how the manufacturer came up with the numbers for each pad, right? Do you think they are lying?

billy

Having one of each I can say the Xtherm  for me is certainly warmer than the Xlite. Although I would like to note again that there are so many variables in sleeping systems and metabolisms that without a decent amount of testing its hard to come to any useful conclusions. Simply changing one variable can leave you confused. Also testing really takes some hard numbers. A reliable high/low temp thermometer is a must. I like to test in my backyard and do it as if I was out. I will spend time in the cold before hand, dressed as I would be when out. I will eat a comparative meal as if I was out and turn in and sleep for the same amount of time. When testing be careful to change only one variable at a time.

I’m a cold sleeper and my head spins off my shoulders when I hear of what some folks can get away with here. They are virtual furnaces in comparison to me (said with a smirk of jealousy). If you have jumped your personal threshold with both mats you would not know if one was warmer. I just went through a process of searching for anything that would keep my hands warm. I tried just about everything in hopes to finding something that would hold in the little body heat that kept my hands from turning blanch white and numb. Finally I discovered that absolutely no mitts are gonna keep my hands from going numb without outside heat input. AKA chemical hand warmers. So after testing I now realize for me there is no difference wearing a 200wt fleece mitt or a BD mercury mitt. Add in a chem pack to one of each and I cant tell the difference except now I can feel my fingers. Of course most peoples hands wearing the BD mitts would be sweating profusely. So again it gets personal sometimes.  I only use this example to show how frustrating testing can be if the one variable eluding you is not yet apparent. IMO the easiest way to eliminate the pads as your problem is to add in more worn or bag/quilt insulation and sleep on your back. If your back gets cold and the rest is toasty your in need of some more ground insulation most likely.

good luck jimmyb

I have them both. XTHERM has always felt warmer than XLITE.

Definitely concur with Bob Moulder about putting the ccf on top of the inflatable—noticeably warmer.  Especially when using a Ridgerest Solar ccf with the reflective silver.

It depends. NeoAirs in general are notorious for “Edge Bleeding” heat away from you. If you use one inside your bag, it is a LOT warmer. This pretty much requires you to have a bag with more girth(>63″) and usually longer lengths(6′.) I have used these down to 10F comfortably with only a base layer.

The Inertia is another option that also works inside a bag.

Theoretically, the dual baffles and triangular construction of a Xtherm is warmer. Every baffle and IR layer works to make smaller pockets. But, the Xtherm Max fails with it’s wider outside dimensions. Generally, this is better for > 10F. Below that and edge bleed becomes a problem. Ideally, they should have a separate baffle along the length on both sides to minimize that. Or, just stick to the smaller Mummy shape where a bag mostly covers the edges.

I also agree with Bob. A CCF pad over an inflatable is warmer. With the edge bleed, most inflatables get fairly cold in 10F and below. (Not something I much worry about.) Usually the temps are much warmer and the bleed does not bother me.

If you use two layers of pad, an inflatable and a CCF pad, use the highest Rvalue next to you. The inflatable can act as a buffer between the snow and your warmth. Then the CCF pad can work to maintain your internal heat. Additive R values only work if both types are the same and under still conditions. Rolling  around on a NeoAir will make it colder by pumping air convection so it cannot stratify inside the pad. Edge Bleed becomes more important as you move more, pumping heat away. Again, theoretically, the baffles run the wrong way (across the width) with the NeoAirs. Any movement will force air (and heat) to the outside edges.

Also note that IR barriers, such as used in the NeoAir do not work well if there is no incoming IR (heat.) And, only one will work, any others are pretty much wasted.

Interesting James.

Would you say that a XTHERM below a CCF compared to a XLITE below a CCF should be fairly similar warm?

“Few people are going to have the resources to literally test the R value, which is a standardized laboratory test with many technical protocols.”

Bob, you bring up such a good point about this. As many of us remember, there was a time when we didn’t see “R value” information coming out of manufacturers. We all had to create our own assumptions based on others and our own experiences, through trial and error.

The sad truth is:

1. There are no standards beyond what each manfacturer chooses to establish for themselves. Since sleeping pads aren’t building materials, they are not subjected to to independent testing and verification.
2. If anything, really is much more about marketing than anything else. Just look at the X-therm page. It tries to convince people that it is the best choice for “extreme cold weather camping”, including an illustration indicating it will do just fine at -40 degrees.
3. Carcade designs uses a 39F degree testing chamber to establish their R value. They don’t test their pads at 20, 0 or -40 (temps that people might actually die at.) It has been proven that temperature affects R value. I have no idea what other companies do. Perhaps they rent a testing chamber.
4. The pad manufacturers have a lot of work to do to create some consistency between them. In the meantime, we will just have to keep sharing our personal experiences & advice and hope for the best for all of us.

@namelessway It has been proven that temperature affects R value

Do you have a source for this?   I’m sincerely curious.

Peter, I believe the Xtherm and Xtherm Max are similar when layered with a CCF pad. Without any sort of insulating materials (just baffles and air,) they have a hard time changing the physics of the pads.

Using a Zrest, (mylar? coated) will block any IR anyway. Unfortunately, any that does get through will get trapped between the Xtherm and the Zrest eventually warming the Xtherm’s upper layer and not reflecting this back to you, directly. The standard NeoAir does this, too. Again, theory says that more baffles is better. A third & forth layer of mylar between the layers, added Xtherm style, will add more than increasing the number of horizontal baffles, though.

Similar to CCF pads, more bubbles per inch of thickness is warmer for identical substrates. So, at the base level, a standard NeoAir initially looks to be equivalent, but the smaller baffles in the triangular shape will allow greater heat stratification. Except at the very apex of each triangular shaped baffle, this is roughly the same as adding a second internal baffle to the Xtherm between all the baffling present top & bottom. (And incidentally increasing strength and easing manufacturing methodology.) In this case, due to the shape, more baffles is also supplemented by an effective additional baffle between the top & bottom, and, is cheap/easy to produce. The fluff simply adds a little more insulation and reduces the “plasticy/sticky” feeling of the original NeoAir.Discounting edge bleed, the XTherm will be a few degrees warmer.

Edge bleed becomes the problem with the larger sized Xtherm at low temps. The Xtherm appears to be optimized for the middle latitudes of the world and not extreme low temps due mostly to the edge bleed. Not strictly true, but you can think of the edges as where the most unheated area of the pad lie. All layers are joined at the edges increasing general conductivity. And the air baffles are all joined there with no insulating value except what the plastic sheets provide. There are no air pockets at the edges to provide any insulation. Every baffle is joined to the edge with the horizontal construction. (I believe they allow internal venting at the edges to simply manufacturing but never took one apart to see.) Since the Xtherm/Max is wider than the typical sleeper, this means any heat loss will connect every baffle at the edges. Edge bleed becomes an important consideration and is not generally considered in Rvalue testing (usually done at each surface to measure the restriction on heat flow.) R value testing is usually static.

Any outside air flow will change this a lot, since convection becomes pretty much unrestricted at the edges. Any movement will cause the cold and warm air to mix. So: sleeping in a tent vs sleeping under a tarp will likely be a different number. Pressure from the sleeper can collapse the internal baffling rendering them ineffective (side sleepers vs back sleepers for example.) Covered, the Xtherm looks to be an excellent choice. Uncovered, it has the same edge bleed as the original and wide pad offerings from Therm-a-Rest. Edge bleed nullifies any extreme cold use without some sort of CCF pad over the whole thing. But, the Xtherm is better at raw R values. How much is difficult to say, it depends on your bag and comfort levels of each sleeper. Again, only the first baffle layer will actually reflect any IR back at you. That they chose to picture the top layer reflecting is consistent with my statement that the best use of multiple layers will have the best insulator on top and as Bob was saying.

If I had my druthers, I would select a pad with a full vertical tube on each side NOT connected to the smaller horizontal baffles on the inside of the pad, and, optimized to insulate against edge bleed (perhaps at a 45 degree angle.) Blow it up firm. This will prevent baffle collapse. And cover completely with a layer of CCF.  The Xtherm works well, but could be considerably better for a slight increase in weight. It would increase the manufacturing difficulty a lot, though. Hell, “best” is the American way. To pay an extra $25 because of the improvement is likely feasible, though.

Last year I formed a theory that any air mat with a TR Rigerest Solite on top of it would work down to 0°F.

I did not have time to test this last year because I was narrowly focused on achieving the lightest combo that was adequate for my whole sleep system, so I ended up going with the 3/8″ CCF and not the Solite. However, I did test 2 or 3 times with the Solite/Trekker setup and found that it was incredibly effective — more than was needed, in fact, down to a little below 0°F for me. The 3/8″ CCF got the job done and weighed about half as much and with less bulk, thus winning the spot in my sleep system.

I still have the Solite and also one of the shortie Neoair Xlites and will test that combo if I get a chance. Thing is, I really don’t like the Xlite because my elbows dangle off the sides, and as a toss-n-turn sleeper it squirts out from under me in the most annoying way. But I’ll try it once in the advancement of science, lol.

Ideally, they should have a separate baffle along the length on both sides to minimize that.

Like on the NeoAir Camper SV ?

James, thank you for your thorough answer. Much appreciated.

Having bought way to many sleeping pads, I’ll try to stick to my XTHERM and XLITE large for as long as possible. Im still very satisfied with them.

@ James

What you describe, is exactly what I experienced, the more I moved around, the colder I got.

To the question about my trust of the empirical value of the manufacturer’s R value claims, the information in the thread confirms that unlike the EN specification for sleeping bag ratings, there is no standardized test for R value.  And more important perhaps, a R value measured in a lab, might not correlate to a user experience in the field,

“Do you have a source for this?   I’m sincerely curious.”

Given my professing in Architecture/building, my personal favorite sources are from http://www.Buildingscience.com. While the publications have to do with building and construction, I judge them to be very relevant to outdoor equipment (since pad companies decided to use “R value” to describe their products.)

Here is one published in 2009 outlining the history of the development of “R” value, and the inherent flaws due to the over-simplification of relying on R value alone.

http://buildingscience.com/file/3175/download?token=lYwGCf8n

And another 2013 publication specifically talking about polyisocyanurate (rigid foam) insulation, and what happens to the materials when subjected to differing temperature. (What is most notable is how all the apparent R values plummet at temps from 35f down to -5.) And this is rigid foam, not a blown up air mattress.

http://buildingscience.com/file/3455/download?token=OowzEOu7

(Since sleeping pads are not “home insulation products”, they have no ASTM requirement to verify their established R value. Furthermore, as the articles indicate, the ASTM testing methods themselves are too simplified and limited in relation to real world application.)

Woubeir, no, though it starts looking like that. That one is very heavy and lacks cold weather baffling.

I think it might look like that, though.

Yeah, I am very happy with the neoairs. Though, I tried the Xtherm, it was simply too heavy.  I am usually UL, so, 12oz on a pad is about it. The older medium works well at 13oz, this is my favorite, but in 32F weather it does bleed quite a bit of heat.Very comfortable for my old bones, though. I still use my 10oz NightLite over it, depending on the temp.

I didn’t mean to take that NeoAir Camper SV. Just the vertical baffle idea of that applied to the Xtherm/Xlite ?