Exped
Down Air Mattress DLX - Field Report
January 7,
2004
Reviewer Information:
Name: Jim
Hatch
Age: 44
Gender:
Male
Height: 5'9" (1.8 m)
Weight: 180
lbs (82 kg)
Sleep Type: Back & side sleeper (neither
warm nor cold)
Email: colonelcorn76@yahoo.com
City/State: Simsbury,
Connecticut
Date: January 7,
2004
Backpacking
Background:
I've been backpacking and camping for 30 years (ever
since I was a Boy Scout). I'm out at least once a month for a weekend or more
and for 5 nights several times during the year. Most of my backpacking is
done in the mountains of the East Coast (Appalachians, Whites, Berkshires,
Adirondacks), but I will occasionally camp as far south as the Florida Keys or
as far west as the Grand Canyon. Having tired of 60 lb (27 kg) loads, I caught
the lightweight bug about 5 years ago and am currently carrying a base pack
weight of 15 lbs (7 kg) before food and fuel and rarely venture out with more
than 30 lbs (14 kg) anymore. I am a hammock camper for most of the year, using a
tent only during winter (under
duress).
Product
Information:
Manufacturer: Exped Expedition Equipment
Year of
Manufacture: 2003
URL: http://www.exped.com
Style: Air mattress, down
filled
Mfg Weight (mat): 45 oz (1280 gm)
Mfg
Weight (packsack): 7 oz (200 gm)
Tested Weight
(mat): 46.1 oz (1308 gm)
Tested Weight (packsack):
6.6 oz (190 gm)
Tested Total Weight: 52.8 oz (1498
gm)
Size: 78 in X 26 in (178 cm X 52
cm)
Thickness: 3.5 in (9 cm)
Rolled
Size: 15 in X 7 in (38 cm X 18 cm)
Tested
Rolled Size: 16.5 in X 7 in (42 cm X 18 cm)
MSRP (pack):
$169
DAM
Features:
The DAM is a down filled air mattress (hence the
DAM acronym) composed of 8 channels separated by quarter-inch (0.6 cm) seams
running nearly the length of the mattress, two air valves at the head end, a 2
inch (5 cm) wide foam barrier running the width of the mattress at both
ends to prevent down shifting, and a stuff sack used to inflate the mattress
without needing to resort to lung power. According to Exped, the DAM is 3 times warmer than
conventional self-inflating foam mats of similar weights due to 11 oz (320 gm)
of 700 fill power down contained within the mattress.
Field
Information:
Overall
Impression-To date, I have used the Exped DAM on two more outdoor
camping trips (details of my first trip can be found in my Initial Report here) and
an indoor Cub Scout overnight. Due to a lack of snow here in the
Northeast, I've had to reschedule two planned camping trips (the expected
snow being replaced by heavy rains). The outdoor trips were in Connecticut's
Bershires (altitudes to nearly 2,500 feet/762 m) with the Cub Scout overnight
bunking in the Boston Science Museum's Dinosaur exhibit. The sleep systems were
down bags and the Exped DAM combined with either a hammock or concrete floor.
I have yet to find a significant
negative to the Exped. It has performed precisely as expected and I've suffered
no untoward events -- no blown seams, leaking down, cold sleeping, or any
real discomfort. Further testing over the next four months may confirm or
invalidate this initial impression. However, right now I am a happy camper.
Sleep comfort is extremely important to my overall well-being when camping
and so far my field & home sleeping has been very
comfortable.
Issues-That
said, although not significant in the overall scheme of things, I do have a
couple of issues. First, it is heavier and bulkier than my other pads. This is
simply a result of basic physics (there's only so much mass that can be stuffed
into any given size). It's marginally smaller than my 35 degree F (1.7 C)
Polarguard filled mummy bag but significantly bigger than my Nunatak
Arc-Alpinist. It's a nit though; I won't be trading back to my GuideLite.
Second, the pumpsack inflation process is tedious and can be somewhat
problematic. Compared to my old pad (open valve, go do camp tasks, come back
& give a couple of puffs and fall into slumber) the DAM's inflation sequence
(see my Initial Report here
for a more detailed explanation & video of the process) takes longer and
requires more attention. Inflating the mattress by lung is
not an option as exhaled air contains large
amounts of water and large numbers of exhalations would be required to fill
the mattress. The water will freeze and make the mattress hard & cold and
the hyperventilating makes me faint. Again, this is pretty trivial as
it's only a few minutes to inflate it on each trip. I've gotten over it.
The Exped DAM is traditional in
shape (long rectangle) but various sleeping systems like hammocks and sleeping
quilts like the Nunatak would benefit from a mattress with a narrower foot
section. Perhaps this is a design change that Exped might consider since even
traditional sleeping arrangements would not suffer from such an alteration.
Finally, this is a significant step up in terms of cost versus a
conventional self-inflating foam mat--although on a "per unit of warmth"
basis it's similar in cost...three times the warmth for three times the
cost. In a perfect world the mattress would be lighter, pack smaller, inflate by
itself, shaped to fit and free! However, in the real world, I
personally find it an excellent balance of weight, size, and cost for the
superior performance provided. Bottom line: great product providing appropriate
value for its cost.
Field Trips:
I have used the Exped on three overnight trips in
the field as well as several experimental nights at home. The field trips
include two in the outdoors (Connecticut Berkshires) and one sleeping on the
floor of a science museum. While not a typical backpacking use, it did provide a
non-critical way to test the pad as well as an extreme of a hard surface to
sleep on (effectively a rock); the museum trip involved sleeping in the Boston
Science Museum in the company of several hundred Cub Scouts (ages 7-10) and 5
dinosaurs (skeletons). Temperature in the museum was 65 F (18 C) overnight. I
used a Polarguard filled mummy bag rated to 35 F (1.7 C) and wore silk shorts
& a cotton tee. I have found that I use about 15 pumps of the packsack to
achieve effective inflation in the field but in this case I underinflated it
using only 10 pumpsack's worth of air. This resulted in a squishy mattress but
firm enough to keep any body part (hips, shoulders, etc.) from bottoming out on
the concrete. I slept the night in the unzipped bag. Normally in this situation
I hover at the edge of sleep tossing and turning waking every hour to pull or
push on either my pad or bag---Cub Scouts and their fathers are not quiet
sleepers. In this case however, I was comfortable enough to sleep through the
night (waking only at 4am for a bathroom break...something to do with the 7-11
Big Gulp no doubt).
On a more traditional note, the other two trips
were overnight backpacking trips involving a hike into camp in the "mountains"
of northwest Connecticut. After my first foray during my initial test the
week I received the DAM, I was looking forward to testing the mattress
under more rigorous conditions to see whose limits were reached first -
mine or the mattress'. These two trips did feature colder temperatures, a
Hennessey Ultralight Backpacker Asym, and a Nunatak Arc-Alpinist quilt. I
usually trade the hammock in for a tent on trips when the temps drop below
freezing (although I've slept reasonably well in it down to the mid-20s F/-4 C
with a Reflectix pad, serious clothing, and windless nights) but expected
the DAM to allow me to continue tree-hanging down to 0 F (-18 C) which is about
as low as I usually encounter except under duress. While the DAM should
eliminate one of my issues with tent camping (hard ground) based on my museum
experience, it doesn't address the weight difference between hammocking &
tenting -- my hammock is less than half the weight of my 4 lb (1.8 kg) tent (as
well as a third of the packed volume).
The Connecticut Berkshires are part of the Appalachians and provide
aggressive hiking, forested mountain trails, and few people in colder weather.
The two campouts involved overnights during dry cool/cold weather at elevations
of 2,312 ft (705 m) and 1,781 ft (543 m). Temperatures went down to 28 F (-2.2
C) with moderate (under 10 mph/16 kph) winds. Humidity levels were unremarkable.
Relevant equipment taken included:
S
ilk long underwear, merino wool socks,
nylon pants, fleece vest and fleece beanie
Nunatak Arc-Alpinist 20 degree F (-6.7 C) quilt with 2 oz (57 g) overfill
yielding a 10 degree F (-12 C) comfort rating
Hennessey Ultralight A-Sym Hammock
The notable result of both trips was that I
was more comfortable with this equipment than on any prior cold weather trip. I
typically will awaken due to feeling cold sometime during the night, although
not in serious discomfort, when sleeping in a hammock at these
temperatures. In these tests I awoke each night for a pee break but not due to
feeling cold. In fact, the combination of the Exped and the Nunatak resulted in
very comfortable sleep. On one occasion I was warm enough to have to open up the
quilt a bit to cool off. The mattress fit into the hammock (barely) and gave it
more structure than is normal. The hammock's traditionally required diagonal
sleep position was not really necessary to stay flat and comfortable. Due to the
size of the DAM I am testing, it wrapped somewhat around & over my head and
feet where the hammock tapers. Hammock camping usually requires a wind
barrier of some sort in weather as warm as 60 F (15.5 C) for some folks but the
DAM appears to provide similar wind protection as no wind/air infiltration was
experienced through the hammock's bottom.
The only real usability issue came from the combination of the Nunatak and
Exped. The Nunatak Arc-Alpinist is a quilt with underside straps designed to fit
under the sleeping pad and a formed footbox (think pocket for the feet). The
rectangular shape and thick construction (3.5 in/9 cm) of the pad made it
difficult to wedge into the quilt. A taper from the knee to the feet with the
pad reducing by half its width at the feet would rectify this without
sacrificing utility. However, with nearly equal amounts of uncompressed down
above and below me led to warm and comfortable nights.
On a technical note, on one of these nights I used an iButton thermochron.
This device is the size of two dimes stacked (0.67 in dia X 0.25 in
thick/17 mm dia X 6 mm) and records time & temperature on a user defined
frequency. Afterwards the data is downloaded into a PC. Typically used in
industrial applications to record the environmental conditions shipments of
goods experience, it is ideal for recording actual temperature performance in
the field. In this case I programmed a 10 minute "refresh" time to have the
iButton record the temperature every 10 minutes. On one night I slept with the
iButton starting off on my chest. It recorded a temperature of 83 F (28 C) for
my surface body temp when I climbed into the hammock. A few minutes later it was
up to 87 F (30 C) due no doubt to the exertion of getting into the
hammock/quilt. Four hours later, shortly before awaking for my pee break, it
recorded a temp of 81 F (27 C). These temps were recorded with the iButton in
the chest pocket of my silk under-tee.
While I emptied my bladder I left the iButton resting on a tree stump where
it recorded an external temp of 28 F (-2 C). I then slipped the iButton between
the hammock bottom and the Exped. My intention with this test was to determine
if I was bleeding heat through the mattress into the outside air. The recordings
through the rest of the night began at the 28 F/-2 C recording and rose to a
high of 34 F (1 C) just before I awoke. Several minutes later the iButton
recorded the same 34 F (1 C) temperature when placed back on the stump as I
started to prepare my breakfast. During the second half of the night I did not
experience any perceived cold issues with my upper body so I presume its
temperature readings continued in the low 80s F (27ish C). At the same time I
was not aware of any cold spots beneath me.
From this data, the techno-geek in me has been reassured with hard data
(versus "mere" perception) that the DAM is an effective insulator. I plan to
repeat the test using a traditional Therm-a-Rest pad to see what "normal"
results are to provide a point of reference to this data.
Current Conclusions:
With these experiences I maintain that the Exped
DAM is meeting its marketing claims. I don't know if it's 3 times as warm as a
traditional pad or 10 times or 2 times (technically speaking the R value is 3
times that of a traditional pad but insulative R-values don't really mean
"warmer" to me). What I do know is that I sleep more comfortably and warmer
using the DAM in moderately challenging conditions. If Exped's claims are to be
believed (and all my experience is that they should be), I will continue to
experience this down to the limits of my normal winter camping weather (0 F/-18
C). This, after all, is what a sleeping pad is supposed to do and what the Exped
is doing so very well.
Long-term testing:
My long-term testing will continue comfort tests
under a variety of sleep conditions including probable colder weather (despite
record high temperatures over the past two weeks, we have re-entered normal
winter weather patterns and are experiencing the bracing effect of 10 F (-12 C)
lows heading down to 0 F (-18 C) this week. This bodes well for more challenging
test conditions on an upcoming snowshoe trekking weekend and our annual
dogsled trip. I will also be camping & kayaking in the Florida Keys
later this winter (yeah, it's an ugly job but someone has to do it) and will
evaluate the DAM's utility in warmer weather (70s F/21+ C) as well as the
packsack's resistance to casual water exposure.
