When it comes to getting a good nights rest you don’t want to cut too many corners. In the backcountry that means down insulation, top to bottom. Nothing is as light or lofts up as well and thus, is as warm as down. When camping on the snow it would seem obvious this means a down sleeping bag, and for ski touring that is pretty much agreed except in very damp conditions where the down is likely to get wet.
For everywhere else, however, down rules. It is particularly valuable as the primary insulation between you and the snow – your sleeping pad. Down underneath you in your sleeping bag provides little insulation because it is being compressed by your body. It provides warmth when it lofts up, not when smashed flat. Thus, a down mat completes, or augments any type sleeping bag with down insulation where it matters most, because the ground can pull more heat from your body than the air because of direct conduction losses.
In combination with a down mat, you may want to add a very thin layer of dense foam as layer number one because if you’re sleeping warm, and hopefully you are, then that warmth could melt the snow. A thin foam pad acts as a water proof barrier to keep the down dry or protect the mat from sharp branches or needles.
To provide full down comfort, above and below you it is hard to improve upon Exped’s Downmat, the UL version, when weight and bulk are at a premium. The small Downmat UL is over five feet long (64″) and 20 inches wide (163 x 52 cm), yet it packs down to a thin 3” x 8”, cylindrical stuff sack and only tips the scales at just over a pound, 18 ounces (500 g). Comfort wise it provides 2+ inches of firm or soft space, insulated with goose down. That’s plenty of space for whatever firmness of mat you want without contacting the ground below.
Part of what makes the Exped down mat so superior is their inflation system. If you just blow it up with with your mouth you will inevitably contaminate the down with the moisture in your breath. Instead their UL down mats come with a simple but effective pump that they call the Schnozzle Pumpbag. It is a stuff sack that you scoop a bunch of air into, then seal at one end by rolling the opening shut, and squeeze the dry air through a nozzle into the mat, hence the name. It only takes about two or three such pumps to fill the mat, and you’re ready for a warm, comfortable sleep.
The Schnoozle idea was around from the beginning for Exped, but they they dropped it for a hand pump that was integrated inside their mats. A nice idea but it increased the weight of the mat, and took a lot longer to pump up than the Schnozzle Pumpbag. The original Schnozzle idea used the same sack as the stuff sack it came with, which required between 8-15 refills to pump up a mat, depending on the size mat used. The new Schnozzle is an included accessory, but not the stuff sack. It is larger, so it only takes 2-3 fills for a small mat, and 4-5 for a full size mat to be full enough for comfort.
You can certainly find cheaper air mattresses, but if you’re snow camping why compromise your ability to sleep well and recharge for tomorrow just to save a few bucks. It may seem worth it at the counter, but not when you miss the summit ‘cuz you didn’t sleep well.
Just how much better is a downmat compared to a regular air mattress? Consider Exped’s own R rating on the various mats they offer, including mats using a synthetic insulation instead of down, or none. Their 7.5mm thick air mattresses offer an R rating of 0.7, the SynMats vary from 3.1 to 4.9 for a 7.0mm thick mat, while the Downmats are rated at 5.9 for the same thickness.
Here’s the real world manifestation of that. On my last ski tour across the Range of Light two guys in the group had a nifty looking, ultra light weight, full length air mattress that was nice and thick. It certainly looked like they would be sleeping comfortable and warm but they complained of sleeping cold every night. They also had heavier weight sleeping bags.
I used a ¾ length Exped down mat with a thin blue pad underneath and my pack was used for insulation around my feet. My sleeping bag was a Moonstone bag rated for about 30° F, with 700 fill down. If I only had a foam pad I would probably have slept cold. While you might think their 3-inch thick air mattresses would be plenty of insulation, it turns out that if you don’t have something to prevent air currents within an air mattress, either foam or some other insulating material (like goose down), the thicker air mattress will actually pull heat from you, rather than insulate you from the cold below. Of course it’s not as bad as direct contact with the snow, but as Exped’s own 0.7 R rating suggests, it’s not a lot warmer, just softer.
Another nice feature embellishing the entire line of Exped’s mats is to the valves. The early mats used big valves that you twisted open or shut. Nice and bomber, but big and bulky. The new generation of valves are flat, with a flap that helps hold the air in when you’re inflating, and a separate valve for deflating. Less bulk, lighter weight, and easier to use.
Don’t be fooled into thinking the down mat is only good for winter when you want insulation from the cold. There is a tendency to think the a down mat is adding warmth and will be too hot for use in the summer. Not so – a good insulator doesn’t add, it just separates you from too much heat, so it won’t overheat in the summer, just provide a comfortable pad with a neutral thermal footprint.
|Size||Dimensions Open||Dimensions Packed||Weight||Price|
|Small||64″ x 20″ x 3″
(163 x 52 x 7 cm)
|4″ x 9″||1 lb. 2.7 oz.
|Medium||72″ x 20″ x 3″
(183 x 52 x 7 cm)
|4½” x 9″||1 lb. 4 oz.
|Lg Wide||77½” x 26″ x 3″
(197 x 65 x 7 cm)
|4½” x 10½”||1 lb. 10½ oz.