Experience with Exped Synmat HL Winter Mat? Looking for a winter pad

I had one in regular wide that I gave to my niece who has just started backpacking…I wanted her to be warm and comfy so I gave her this one.  I was always toasty on this pad.  I find Exped pads to be the most comfortable for me, but some might find the xtherm to be more durable.

@dgposton

The thread I needed to see because I’ve been looking at this exact pad!

I would think an R of 5.2 would be fine for winter,  if ever in doubt bring a CCF.

Btw, the exped downmat MW has an R of 7, and is about the same weight as the xtherm large

Forget what the industry says about ”winter” sleeping pads. Sleeping bag EN/ISO ratings are based on an R 4.8 pad – year-round. Some people think we should be always use an R 6 mat to get to those ratings.

Yes, many people are happy (or tolerant) of pads with lower R-values. But other factors come into play, including youth, fitness, traditional gender, shelter, wind, hydration, last meal, other clothing, etc. Plus people using a bag rated 20 F on a 35 F night, then saying “I slept well on an R 3 pad, what’s the problem?”

R 6 and higher probably won’t hurt – except in weight and your pocketbook. Also, Therm-a-Rest R-values jumped up when they started fully inflating pads to meet the latest standards – no re-design was involved. Previously, they used 80% inflation, because their research showed that most customers couldn’t stand sleeping on a fully inflated Therm-a-Rest. OTOH, I sleep well on a maximally-inflated Nemo pad, and I need a cushy bed at home.

For such a seemingly simple product category, sleeping mats are a mess, and the industry keeps confusing things more. SUL base weights are great, but so is a good night’s sleep.

— Rex

Sleeping Pad R-Values: Not That Useful
https://backpackinglight.com/sleeping-pad-r-value-not-that-useful/

Improving R-Values for Consumers
https://backpackinglight.com/improving-r-values-for-consumers/

Standards Watch: Sleeping Bag Temperature Ratings
https://backpackinglight.com/standards-watch-sleeping-bag-temperature-ratings/

I really like my REI FLASH All Season R 5.3 insulated air mattress at 17 oz. It has worked for me at 10 F.

I like it so much so that I also have the similar REI FLASH 3 season insulated R 3.5 air mattress. A Sea to Summit pump/dry bag inflates both mattresses because REI was smart enough to get permission to use the StS valve system.

I really like my REI FLASH All Season R 5.3 insulated air mattress at 17 oz. It has worked for me at 10 F.

I like it so much so that I also have the similar REI FLASH 3 season insulated R 3.5 air mattress. A Sea to Summit pump/dry bag inflates both mattresses because REI was smart enough to get permission to use the StS valve system.

Hmm.  That’s a decent R-value for 17oz, and I didn’t know about the S2S valve compatibility.  I might look closer at REI next time I’m in the pad market.

The SYNMAT UL WINTER has it’s two outer (edge) baffles being much wider than the rest of the inner baffles. So, for me, there was no good place to place my elbows when sleeping on my back. Either the elbows slipped off to the side, or, the next best place, between the outermost baffle and the next one, was too narrow.

You may want to see if the Winter HL is the same, in this way, as the Winter UL.

Were you using the wide width pad or the regular width?

20″ wide, rectangular.

A cautionary tale

My go-to mat for three season use is the S2S Etherlite XT which is 4″ thick and R3.2.  S2S advertises this pad to be a three season option and does not claim it to be suitable for winter use.  I agree with that assessment but more on that in a minute.

For comparison your mat the Exped Synmat HL is advertised on their website to be 2.8″ and R2.9 ASTM R3.3 EMPA.

They aren’t perfectly comparable but the R values are close enough for government work.

For me I’ve found that it doesn’t matter all that much what the lowest air temperature reading of the night is as much as the ground temperature.  This seems like common sense but I find I can get away with using a three season pad in late fall/early winter, but can’t use it and stay warm in deep winter.

I bring this up because I hear people talk about how a system works where they mention the lowest air temperature but don’t mention if the ground is frozen.  There’s a big difference between a scenario where the air temperature warms up and thaws the ground every day, and when temperatures have been below freezing for two weeks and the ground is frozen solid.

The ground has enough thermal mass that it requires more than a singular night of cold temperatures to actually freeze up (talking about driving tent stakes into concrete).  Once the ground has frozen up, I find these three season pads to be inadequately insulated.

This is also where experience is the best teacher versus arguing theory online.  Over the years we’ve debated here in the forums if R values were cumulative.  Maybe they are and maybe they aren’t, but it seems there are more variables in play and it’s not simply a matter of R 3.3 S2S etherlte plus R 2.1 Ridgerest equals R5.4 in comfort.

As a personal experiment, I recently tried this in the cascades a couple weeks ago.  The ground was completely frozen and it felt like we were driving our stakes into concrete.

On night one I slept on just the S2S Etherlite.  On night two I combined the S2s with the Ridgerest underneath it.  Unfortunately there wasn’t a third night or I would have slept with the Ridgerest on top of the Etherlite.

There was no perceivable difference and I found I was cold both nights in a sleeping bag that’s proven to be warm down to sub zero temperatures (lowest air temp was 19*f).  I’m ordinarily a warm sleeper.

I have a mummy shaped X therm.  I should’ve brought it but I’ve become so accustomed to rectangular 24″ wide pads that I guess I hoped I could get away with combining two pads together.  Maybe there are properties unique to the Exped where you’d sleep warm on it.  Dunno.  My Exped failed years ago and I never replaced it.

Moving forward, I’m buying the X therm Max for four season use and saving my S2S as a loner.

Ian,

Thanks for the interesting and detailed account.  I decided to buy the X-therm and the Exped HL Winter Mat (medium wide) to test both side by side and return the one I don’t want. I have the X-therm at home now in my living room floor.  Lying on it, again, my back doesn’t feel nearly as comfortable as my Exped HL medium wide (not winter).  Something about the horizontal baffles I could never get used to after owning a NeoAir many years ago.  When the Exped HL medium wide arrives, I’ll weigh it and see if the difference is weight is worth the discomfort of owning the Xtherm.

With regard to ground temperatures, let’s say I’m sleeping in a shelter on the AT where the ground isn’t frozen (this is a likely scenario for my upcoming hike), but the air temperature is 17 F.  I’m wondering in that case if I could get away with my Synmat HL (not winter).  I’m not sure I want to test it though haha on a 5 day trip.  I generally run cold (around 10 percent body fat) and I’m not really experienced with winter trips.

I thought of carrying a 3 oz 1/8″ thinlight with my Exped HL (not winter) but I’d be carrying an extra 3 oz whereas I could just bring the Exped HL Winter mat for those 3ish oz and be much warmer.  Anyway, I’ll give an update when the pad shows up.  Had to order it from Canada for $200 USD (not cheap), it was out of stock everywhere.  REI doesn’t seem to even carry Exped UL mats anymore.

@Rob

I’m using the medium wide pad.  The HL pads in regular width seem to be way too narrow, especially at the bottom.  My feet slide off.  It’s much more aggressively tapered than the NeoAir series.  And I’m only 150 lbs and 5’7″-5’8″

@dgposton

I’m very interested in what you find out,  im very tempted to do the same thing with the same mats!

If you’re in a shelter off the ground I’d think you’d be ok with the ccf pad as a backup.

An easy test would be is if your temps are close to what your expecting where you live, give it a test run at home, just put it on a table or bench or mock something up!

With regard to ground temperatures, let’s say I’m sleeping in a shelter on the AT where the ground isn’t frozen (this is a likely scenario for my upcoming hike), but the air temperature is 17 F.

I’m reminded of similar thread a handful of years ago which relates to this question. But in my mind the ground might likely be a “warmer” option over a wood floor with 17 degree air circulating underneath of it:

https://backpackinglight.com/forums/topic/question-for-the-science-guys/

“But in my mind the ground might likely be a “warmer” option over a wood floor with 17 degree air circulating underneath of it”

^^this.

FYI: There is a difference between the regular HL (“hyperlight”) and WINTER hyperlight.

HL: R=2.9

Winter HL: R =5.2

Then, there is the UL, and UL winter:

UL: R=2.9

Winter UL: R=5.2

The difference between UL and HL is that the UL are rectangular and the HL are more of a mummy shape (to cut down on weight). Otherwise, the materials and insulation are the same with both UL and HL pads.

The winter versions of UL and HL have more synthetic fiber insulation and are thicker.

insulation: 200g winter, vs. 60g

pad thickness: 3.5″ (winter) vs. vs. 2.8″.

Exped has a lot of different pads!

I love exped pads … I have a few and the / Customer service is really good… I had a mega Matt for car camping that was about 12 years old or so one of the seams finally blew out I sent it in and they replaced it with a newer version for free and that was only supposed to be under warranty for I think five years I had another syn  mat that was like 12

years old That went in to delamination and they replaced it with a pad of my choice for free I opted for syn mat 3 D long wide and I love it it’s a bit heavy  but warm good down to 1” F so I don’t have any specifics to offer about the particular pad you were looking at  but I can’t say enough good things about   exped …good luck … I think tounwill be happy with there pads

The S2S Etherlite XT is quite thick at 4 inches. I could see that impacting its ability to supplement its R-value with foam pads underneath. There might be a lot of heat loss through the sides. I’ve noticed that my S2S Ultralight Insulated feels much warmer with a 1/8” pad underneath, but I don’t notice any warmth increase using a 1/8” pad under my Nemo Tensor Insulated. I like my Tensor firmly inflated.

The Exped Synmat HL Winter does look like a pretty good pad. I’m still leery of all the delamination failures I’ve read about on Exped pads, but maybe that’s a thing of the past.

I’ve never tried the Etherlite, but my experience is that I can stay warmer with a Ridgerest placed on top of a inflatable or self-inflating pad rather than underneath.  YMMV.  Try it out in your backyard.

Knowing that the obvious high R- value choice, the NeoAir Xtherm,  doesn’t work with my back,  I started researching air pads again.  The Exped Synmat HL Winter Mat also rose to the top of my short list.  I have an older, burlier Exped pad that is very warm and comfortable but it weighs 29 oz.   My hesitation with  the UL air pads is the 20d fabrics.  My Synmat UL 7 was a great pad. but it didn’t last much longer than the 2-year warranty.  It gave out on me in the summertime, so it just made for an uncomfortable night, nothing serious.  Not sure I would trust it (or myself with it) in the winter.

So right now I’m just waiting, reading about other hikers’ experiences, and either using my heavy Exped pad or combining my Ridgerest with a 3-season pad.

@dondo

I’m with you–the NeoAir series just doesn’t seem to work with my back either.  There’s something about the horizontal baffles on the NeoAir that doesn’t feel good on my low back…it’s hard to explain but I feel more comfortable on the vertical baffles on my Exped pads.

As far as durability.  My Synmat UL 7 from circa 2014 or so blew out on me after a few years of use.  Exped sent me a brand new replacement, which is still sitting in the box.  I purchased a HL medium wide in 2017 and have used this for 4 years now.  I plan to do a video review one of these days on this pad–it’s awesome.  No issues with it.  I think they fixed the issues with delamination around 2016.

When my Synmat HL Winter medium wide pad shows up, I plan to do a comparison video with the NeoAir Xtherm.

@yoyo

Thanks for the great information on Exped.  You post goes a long way in alleviating my concerns.  It appears that they have recognized and addressed durability issues and now are confident enough to extend their five-year warranty to the UL/HL line.  Your experience shows that they do stand behind their products.

I’m looking forward to watching your videos.

“The S2S Etherlite XT is quite thick at 4 inches. I could see that impacting its ability to supplement its R-value with foam pads underneath.”

Maybe.  It’s only a half inch thicker than the Exped Downmat UL.  I think it has more to do with how they’re built and insulated.

I can’t fault what’s advertised to be a three season mat for only being suitable for three seasons.  For 7-8 months a year, it’s a very comfortable pad and has given some of the best nights of sleep.

My last experience with an Exped pad was a Synmat a handful of years ago.  I didn’t have a catastrophic failure.  I had a small leak and I could have fixed it.  Around that time, quite a few BPLers had some fairly epic delamination and I was worried that I was on borrowed time with it.  I retired it and haven’t considered the Synmat or Downmat since.

It sounds like they’ve improved their quality and I may have to consider the Downmat UL over the X therm.  When I used it, the Synmat was pretty comfy.