Exped DownMat Pump 7 Short (black, top) and Exped SynMat UL 7 Short (yellow, bottom).
This mini-review is part of Part 2 of our survey of airmats. It may be that Exped was the first to popularise the idea of a Down Air Mat, or DAM. Certainly many winter walkers have made known just how warm and comfortable they became when they accepted the weight penalty and bought one of these. The problem with DAMs is that blowing them up with your mouth puts moisture into the down, which is not a good thing. Exped solves this problem by including an internal pump in their DAM.
The SynMat is rather similar to a DAM in a way, in that it contains full-length insulation. However, unlike many other mats, which have a layer of synthetic insulation bonded just under the top surface, this one has the rather thin layer of synthetic insulation bonded at both top and bottom surfaces. This means it expands and fills the volume when the mat is inflated - a new idea, potentially rivalling down. The use of synthetic insulation means that any moisture getting in is unlikely to damage or shrink the insulation. If you use one of the Exped external pumps the whole problem of moisture is solved.
DownMat Pump 7 Short
|Length||120 cm / 47.2 in|
|Width||52 cm / 20.5 in|
|Thickness||7.0 cm / 2.8 in|
|Weight||626 g / 22.1 oz|
|R-Value||3.3 - 9.4|
|Drag Force||14/23 N|
|Insulation||700 loft goosedown|
|Larger Side Tubes||Yes|
This is only the Short version, and it may be that many would prefer a longer version of this mat for use in the snow, and that would be very reasonable too. But the weight of the next length up (183 cm / 72.0 in) was 880 grams (31.0 oz), and that was over our self-imposed limit of 800 grams (28.2 oz). There are other even more luxurious versions, but even heavier.
The mat has two valves: one for the pump inlet (bottom, middle) and one for letting the air escape in the morning (top left corner). There is foam over the outlet valve to keep the down fill inside. You spread the mat out, close the outlet valve, and open the inlet valve. Then you start pumping up and down on the sponge-filled pump region. But there is a trick here: you have to block the inlet valve with the palm of your hand on every stroke if you want the mat to inflate. It isn't very difficult, but I cannot see why they didn't put a very simple flap over the inside instead. It would make pumping so much easier! (Note: in their more recent SynMat, discussed below, they do have such a flap over the inlet valve. Definitely progress.)
The only other mat in this survey with an internal pump is the Mammut Light Pump mat. I found it curious that no American company has been this innovative. By way of comparison, the Exped pump region is a two-hand job, as you can see from the drawing on the mat, while the Mammut pump has room for only one hand. That means the Exped should inflate much faster. It's hard to compare the inflation rates as the Mammut mat is much bigger, but the Exped did reach full inflation quite fast. Both (Mammut and Exped) usee very similar valves. In fact, the valves and the foam pump area do look very similar in each: one wonders whether the pump parts at least are all made in the same factory? It hardly matters though.
The Exped mat has two attachment holes at one end: they say the holes allow you to tie your pillow to the end of the mat. This is not a silly idea: it makes the Short mat seem much longer. Mind you, it also assumes you have enough extra gear to make a fat pillow: perhaps food bags could be used as well? Or perhaps you could use a custom pillow such as their Pillow pump (or the MontBell pillow). However, see Roger's comments below about this as well.
The mat has larger tubes at the sides: they do help to keep you in the middle of the mat. The slipperiness of the bottom surface is a bit high compared to many others, but that problem seems to be countered somewhat by the side tubes, and also by the generous width and the rectangular shape. It is curious that the top surface is less slippery than the bottom surface.
Comments by Will Rietveld
I slept on the DownMat three nights with temperatures of -3 C, -3 C, and -1.7 C (27 F, 27 F, and 29 F) in a one-man double-wall tent. Although it's a heavier pad, it was definitely quite comfortable. As far as pure comfort goes, it's the best of all the pads I tested. It feels like sleeping on my regular bed at home. Since the pad is a Short, I needed to use my backpack as a pillow and place some clothing under my feet. A longer version would be desirable for sleeping on cold nights, but I would not want to carry the extra weight.The pad's built-in pump feature works well, but adds weight. The rectangular shape of the mat makes it feel extra wide, so it's easy to stay on when turning over. I also found it to be very slip resistant.
It weighs a little more than the Big Agnes Insulated Air Core, but its warmer and a lot more comfortable. Overall the DownMat is deluxe as far as warmth and comfort, but that comfort comes with a weight penalty.
Comments by Roger Caffin
You can use the pump to blow this mat up moderately hard, but I found that it was best if I left it just slightly below that in pressure. This is quite normal. What was a bit less expected was that I found it very hard to inflate the mat past a certain point. I just could not make it 'hard' - not that I wanted to anyhow. Whether this is a deliberate feature or it just happened that way I cannot tell.
People have complained that short thick mats like this one present a serious 'drop-off' at the bottom end for their legs. If you inflate this mat hard that may happen, but you do not need to do that. I found that a 'comfortable' (ie a bit soft) level of inflation meant the drop-off at the end was not really significant. A bit of clothing or gear there to ease the transition helps of course, and you will need a bit of foam or something under your feet for insulation.
But I got a bit creative about this drop-off problem. I turned the mat around, so that the small cross-tube at the end was at my feet. It is not as thick. Then I made a quite high pillow off the end of the mat, keeping it in place by jamming it between the mat and the bathtub wall at the end of the groundsheet. Finally I put one of our fold-up sitmats (which we always carry anyhow) under my feet. The result, as you can see here, was that when I was sleeping on my side little more than my feet were actually hanging off the end of this mat, and the cross-tube made a really nice transition. The mat shown may be a 'short' version, but with a bit of cunning it can be made to be adequately full-length for me.
SynMat UL 7 Short
|Length||163 cm / 64.2 in|
|Width||52 cm / 20.5 in|
|Thickness||7.0 cm / 2.8 in|
|Weight||436 g / 15.4 oz|
|R-Value||2.1 - 3.7|
|Drag Force||12/10 N|
|Insulation||60 g/m² Texpedloft Microfiber|
|Larger Side Tubes||Yes|
This is a very interesting mat as it combines fairly light weight, long length, good thickness, and internal insulation. It has two holes at one end, both with soft valves (possibly silicone rubber). These valves are exactly the same as shown on the photo of the DAM at the start. There is an inflation hole which has a valve to prevent the air from coming straight back out again, although you are advised to seal the hole with the attached plug as soon as you have finished blowing it up. The valve is not meant to provide an overnight seal. Next to the inlet hole there is an outlet hole. This too has a valve inside it, but this valve is very different. It lets the air out, and is kept shut by the sealing cap pressing down upon it when inserted. As soon as you remove the sealing cap the valve pops open and the air rushes out. I am led to wonder why Exped actually bothered with the valve insert here, as the sealing cap should be good enough to make a seal by itself. Perhaps that is so, and Exped is just being very cautious.
In all other mats with internal insulation, one finds it bonded to the inside of the top surface. This is the obvious place of course, but the insulation in the SynMat UL is bonded at the top and bottom surfaces, so it expands or fluffs up when the mat is inflated. The illustration here is from the Exped website, and somewhat diagrammatic, but it shows what happens. So what is the difference between this idea and a down filling? Well, the weight of the fill is much lower, so it isn't going to be as warm as down, but it does not do too badly. Exped rates it to -4 C (25 F), but we tested it well below that. More importantly, the synthetic fill can handle getting damp, while down can't.
As mentioned in Part 2 of this series, when you breath into an air-filled mat, you are injecting moisture, and on a cold night this moisture will condense and become visible, as shown here. However, while such moisture would kill down insulation fairly quickly, it is unlikely to have much effect on the synthetic insulation used here. Due to your body warmth at the top and the cold ground at the bottom, any such moisture will quickly condense out on the bottom surface of the mat, where it won't do any real harm.
Of course, the best option is to not inject the moisture in the first place, and Exped sells a couple of accessory pumps just for this purpose. They are foam-filled (and hence self-inflating) and clip into the inlet valve on any Exped mat. The Mini Pump is the lightest at only 40 g (1.4 oz), but it is too small for anything except acting as a pump. The next one up is the Pillow Pump, at 160 g (5.3 oz). Granted this is heavier than my cored foam pillow, and twice as heavy as the MontBell pillow, but it is a very convenient pump. If we allow 80 g (2.8 oz) for a light pillow, this means there is an extra 80 g for the pump function. Is this worthwhile? On a long cold trip it may well be so.
Comments by Roger Caffin
We took this mat on a lightweight alpine trip in late autumn in the Kosciusko National Park near Mount Jagungal. The first night hit -3 C (27 F), and I slept very comfortably on it. My wife Sue was using another somewhat thinner mat that night. The second night Sue pinched the SynMat off me to try, and had a very good night's sleep at a similar low temperature. The third night it got down to -9 C (16 F), and again Sue slept very well - she had refused to hand the SynMat back. I managed with the thinner mat... oh well, such is life. It should be noted that Exped only claims a rating of -4 C (25 F) for this mat: not much hype there. The fourth night it snowed about 100 mm (8 in), and that did precipitate an abrupt exit from the mountains in our mesh-top low-cut joggers.
A very funny thing happened when I went to inflate the mat on the evening of the third night: I couldn't get any air into it. Oh dear me - what has happened? Then I realized (OK, I guessed) what had happened. It had been cold all day, and by the time we got the tent up, it was already well below freezing (and the wind outside was biting). The little bit of moisture already inside the mat had frozen the valve shut! That was soon solved with some hot breath, but it shows that moisture inside an airmat may have all sorts of bad effects.
This is a mini-review in the 2011 Lightweight Airmats State of the Market Report. The articles in this series are as follows (mini-reviews can be found in Part 2), and a subscription to our site is needed to read them.
- Part 1 covers the basics, testing methods, and lists all the mats in the survey.
- Part 2 examines the actual mats, and the performance of each mat tested.
Disclosure: The manufacturers provided these products to the author and/or Backpacking Light at no charge, and they are owned by the author/BPL. The author/Backpacking Light has no obligation to review these products under the terms of this agreement.