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Reviews > Shelters > Tarps and Bivys > Integral Designs Penguin Bivy > Test Report by Gail Staisil

Integral Designs Penguin Reflexion Bivy
Test Series by: Gail Staisil, Marquette, Michigan

Page Contents:

Initial Report:
Integral Designs Penguin Reflexion Bivy
March 2, 2008

Tester Information

Gail Staisil
Age: 55
Gender: Female
Height: 5' 9" (1.75 m)
Weight: 138 lb (63 kg)
Chest: 37 (94 cm)

Hip Girth: 37 in (94 cm)
Shoulder Girth: 41 in (104 cm)
Location: Marquette, Michigan USA
Email: woodswoman2001 AT yahoo DOT com

For the last 18 years, backpacking has become a passion. I am a four-season backpacker and an off-trail navigator. Although I do take yearly trips to the American West or Southwest, the majority of my trips are in Michigan and Canada. My pack weight varies considerably but my base weight is below 18 lb (8 kg). I am primarily a tarp camper who averages more than 50 nights a year backpacking in a huge variety of weather conditions including relentless rain, wet snow and sub-zero temps (0 F/-18 C).

Product Information

Integral Designs
Model Penguin Reflexion Bivy
Sympatex Reflexion (100 percent)
Packed Size
3 in (7.62 cm) X 3 in (7.62 cm) X 14 in (35.56 cm)
Tested Size
One Size: 7 ft (2.13 m) long (fits to 6 ft 4 in/1.93 m)
Girth Measurements by
Chest Girth: 76 in (193 cm), Hip Girth: 64 in (163 cm), Foot Girth: 42 in (107 cm)
Girth Measurements by Tester
The above measurements were very accurate :)
Manufacturer  Weight 
23 oz (650 g)
Tested Weight 
23.2 oz (658 g)
Model Year 2008
Country of Manufacturer
Canada (Calgary, Alberta)
MSRP $265.00 US


Initial Impressions and Product Description

Stuff sack with Penguin BivyIntegral Designs Penguin Bivy
The Penguin Reflexion Bivy is one of numerous bivies manufactured by Integral Designs. Marketed as a winter, high altitude and rescue bivy, it's their only model fabricated with Sympatex Reflexion. This 3-layer fabric has a silver reflective inner membrane (aluminum) that reportedly traps back body heat and adds warmth. Other qualities of the fabric include the ability to be waterproof, windproof and breathable. The Penguin arrived in seemingly perfect condition encased in a small silnylon stuff sack (dimensions above). The outside of the bivy appears much like it did on the website.

According to the manufacturer, the Penguin bivy "was inspired by the Emperor penguins of Antarctica, which are able to withstand brutally cold winter weather due to their aerodynamic shape and built in insulation, which traps their body heat." Being a cold sleeper, I look forward to testing its inherent ability to add warmth to my sleeping system.


Besides using Sympatex Refexion for fabrication, the Penguin also
differs from other bivies I have used in that it has a cZipper ribbon pullenter zipper opening. This long approximately four foot (1.22 m) waterproof zipper starts at about waist height and extends to the top of the head. The zipper is inserted into a curved seam so that the top of the bivy forms a dome shape area over my face. The zipper features three sliders with approximately 3 in (8 cm) long ribbon pull tags so that an opening can be created wherever I would like along its length for air to escape. There is an additional way for air to esTunnel ventcape however, and that is from the mesh-covered tunnel vent that is located near the top of my head. The circular 4 in/10 cm (diameter) opening on the tunnel can also be totally closed by the means of an internal drawcord. There's a hang loop on the outside of the tunnel vent to presumably maximize the venting capability of the vent. It would have to be tied off to a stake, pole or perhaps a tree branch.

Being a winter specific-bivy, it doesn't feature a full mesh netting option over the upper half of the body to protect the face and other skin areas from bugs in the late spring and summer months.

More Details

As stated above, the Penguin Reflexion Bivy is more than two pieces of flat material sewn together. It has an overall tapered shape with the lesser width of 42 in (107 cm) being at the foot of the bivy and the greater width of 76 in (196 cm) located at the chest area.

The back of the bivy consists of two pieces of fabric sewn together with the upper portion forming a half-dome shape. The footbox area of the bivy is formed by inserting an oval-shaped piece of fabric between the front and back panels.

The front of the bivy consists of a one-piece lower half but the upper half is additionally pieced with each upper side consisting of four angular pieces. This creates an approximate pyramid dome-type shape to presumably allow for roominess and comfort. The tunnel vent is inserted above the upper end of the zipper where the back and front sections merge. All of the seams are beautifully seam taped eliminating the need for additional seam sealing. Upon overall inspection, the workmanship on this bivy is topnotch.

The only adornments on the bivy are a triangular chest emblem with the Integral Designs logo and the words "Integral Designs" are also embroidered on the zipper pull ribbons.
There are also two stake loops located one on either side near the shoulder areas of the bivy. These could be used if I were to sleep in a precarious position such as to prevent sliding.

A Quick Tryout 

I was anxious to try out the Penguin Reflexion Bivy. It's available in only one size and the length and girth measurements (as stated above) suggested that it was roomy. I took out my -20 F (-29 C) sleeping bag and inserted it into the bright yellow-gold colored bivy. There seemed to be plenty of space for both the loft of the bag and for me to use my arms without restriction inside the bivy. There's also room at the bottom of the bivy to store a few small items while I'm sleeping.

When I crawled into my sleeping bag with the bivy over it, I tried rolling from side to side. I liked how the zippered vent stayed in place over my face. Because the bivy is made entirely out of the same Sympatex Reflexion waterproof fabric on both top and bottom sides, there isn't any reason that I can't move the entire bivy with me as I toss and turn. Normally with most side-zippered bivies, I have to re-create a breathing space when I turn to the opposite side as the breathing hole is out to the side. I'm really looking forward to testing this aspect of it in the field. An internal tag advises the user to keep the zipper open 6 in (15 cm) to avoid suffocation. No worries there as I like to have a breathing hole rather than being fully encased in a bivy.



Care instructions are printed on a tag that is inserted into the seam around the tunnel vent. The bivy should be hand washed with mild soap and then hung to drip dry. Dry cleaning and bleach are forbidden. 

So far, I have a very optimistic view concerning the features of the Penguin Bivy. I will be going on a five-day winter trip next week and I'm looking forward to using the bivy then and throughout the next four months of winter and spring adventures.

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Field Report:
Integral Designs Penguin Reflexion Bivy
April 29, 2008

Locations and Conditions

During the field test period, I have slept in the Penguin bivy every night during a five-day sledge trip and a four-day backpacking trip (total of seven nights). Locations ranged from and included conifer and deciduous forest communities with many rock outcroppings to frozen lakeshores and wet swampy areas.
Elevation ranged from 600 ft (183 m) to approximately 1200 ft (366 m).

March Sledge Trip:

Location: Pictured Rocks National Lakeshore - Upper Peninsula of Michigan
Type of Trip: Winter sledge (bushwhack) trip
Distance: 19 mi (31 km)
Length of Trip:
5 days
Total Sledge Load (including consumables): Estimated 60 lb (27 kg) 
Sky and Air Conditions: Cloudy, sunny, mid-high humidity
Precipitation: Trace of new snow
Temperature Range: 34 F to - 4 F (1 C to -20 C)

April Backpacking Trip:

Location: Mackinac State Forest - Lower Peninsula of Michigan
Type of Trip: Bushwhack, partly snow-covered forest and swamps
Distance: 13 mi (21 km)
Length of Trip:
4 days
Backpack Weight (included transport of snowshoes, traction devices, etc): 42 lb (19 kg) 
Sky and Air Conditions: Sunny, partly cloudy
Temperature Range: 23 F (-5 C) to 63 F (17 C)

Performance in the Field

So far, I have spent seven nights sleeping in the Penguin Bivy. I love many of its attributes but especially the center zip and the fact that the same fabric makes up the entire bivy (more about that below). The bivy is a bit more tapered at the foot end than any other bivies I have owned so placing a lofty bag inside that end is more of a challenge.

Usage and Comfort

The Integral Designs Penguin Bivy was first used on a five-day sledge trip. During this trip I used a -20 F (-29 C) down sleeping bag in combinationMorning arrives for the Penguin Bivy-clad tester with the bivy. Although I ordinarily sleep with my insulated pads underneath a bivy, my first observation was that there wasn't any way that they would fit inside the bivy without compromising the loft of a cold-weather bag. The footbox area that measures 42 in (107 cm) feels confined with that particular sleeping bag.

Each night as I layered together the sleeping bag and the bivy, I would have to slowly thread the lower end of the sleeping bag down into the lower section of the bivy. This also limited any idea of storing anything that needed insulation in the area between the bag and the bivy. However, there was at least a foot (30.5 cm) of empty space that was left between the bottom edge of my sleeping bag and the bottom edge of the bivy. That could be used for storage of items that didn't need insulation.
The most comfortable aspect of this bivy for me is the placement of the zipper. As I hinted at in the Initial Report, I'm a side sleeper who changes positions a few times during the night. I am completely taken (delighted) with the fact that I no longer have to re-zip the whole zipper to create a breathing hole.

Being that the entire bivy is made out of waterproof Sympatex Reflexion material, turning the bivy with me from side to side doesn't matter as I still have the waterproof material underneath me.
The shaped area created by the extra fabric inserts in the front of the bivy over the face area stay adequately away from touching my face. Although my sleeping bag has a side zipper, the opening of the bivy is wide enough that I don't have to displace everything in order to get in it.

As implied, the bivy is very easy to enter and exit. However there's one minor annoyance that I immediately noticed. Although there are zipper tabs on both the inside and outside of the bivy, the handy ribbon pulls are only on the outside of the bivy. I usually leave one of my hands outside of the bivy to pull the zipper by the ribbon but it is awkward to do so.

Reflective Quality
The Sympatex Reflexion Material used to make the entire bivy has the quality of transferring body heat back to the user. I'm not sure in theory how this could be accurately tested, but I felt warm during all the nights of the trip. My sleeping bag was rated colder than actual temperatures but I am indeed a cold sleeper who requires more warmth than the average person (I normally carry a bag that is rated 20 degrees colder than predicted temps).

I also use two insulated pads to insure warmth (one being a simple closed-cell foam pad and the other being the Pacific Outdoor Equipment Hyper High Mat). I assume that the aerodynamic shape of the bivy has much to do with how the reflective qualities work. As earlier stated, there is little air space between the sleeping bag and the bivy especially in the bottom half. This would most likely trap air and help reflect it back.

The Penguin Bivy in my shelter of snow and tarp
Condensation - Little Frost

I did experience some frost inside the bivy but it was mostly located in the areas surrounding the breathing hole created by leaving an opening in the front zipper. I didn't notice any perceptible frost at the tunnel vent (open position) or in the lower portions of the bivy when I exited each morning.

The lowest night temperature on this  trip was -4 F (-20 C).
While I was sleeping under my tarp on the first night of this trip, light snow settled on the bottom part of the bivy. It slid off quite easily once I started moving my legs.

During this trip, I often slept close to the snow walls of my shelter. The Penguin Bivy protected me from any moisture that such contact sometimes provides.

I also have enjoyed the softness of the Sympatex fabric. There isn't any crinkling sound and it's so easy to pack. It didn't stiffen from the cold and the snow but the fabric remained very flexible.

Carried for Survival Gear

During one day of the sledge trip we took a short side trip off the main course. We left our loaded sledges with gear at the top of a steep descent. We packed a small day pack with assorted climbing gear, survival gear and snacks. I packed the bivy in this pack and took it with me as a safety measure.

Our side trip to explore the ice columns produced by frozen waterfalls (hanging over the sandstone cliffs) took several hours. The Penguin Bivy was carried for emergency purposes but luckily it didn't have to be used as a rescue bivy. It was easy to stow in my small pack and definitely was worth including in survival gear.

Second Field Trip

My second trip in the field test period was a four-day backpacking trip. Even though the calendar said it was springtime, the ground was still mostly snow-covered and the nights were chilly. The low temperature for this trip was 23 F (-5 C) and the other nights were certainly not much above that.

I chose damp and barren ground for my pyramid tarp set-up but the ground was still quite frozen as evident when pushing in the stakes. This translated to a very cold ground and on this trip I packed a simple three-quarter sized Z-Rest Pad that I shingled with a Pro-lite 3 Pad so that my torso and hip area could be insulated from the ground.

I also used a 20 F (-7 C) synthetic sleeping bag in combination with the Penguin Bivy. This particular bag has never been warm at that temperature for me. During the first night, I had trouble keeping warm. I had the bivy zipped up with just approximately a 8 in (20 cm) opening so that I could both breathe and see outside of the bivy.

In addition to wearing long underwear and trail pants, I wore two shirts and a synthetic-filled vest on my upper body. Since I was still cold, I put my down jacket over my sleeping bag inside the bivy and things were great. I repeated the pattern for the remaining two nights so that I would avoid sleeplessness due to being cold.

Overall, the nights were windy and damp. The bivy protected me well from the winds but the dampness is probably what made me feel cold. The amount of clothing I wore inside the sleeping bag most likely hindered the amount of heat that could have exited the sleeping bag. This in turn no doubt wasn't very effective for the reflective quality to work.

More Roomy with Less Lofty Bag


I did notice on this trip that I had a lot more room in the bivy due to the less lofty sleeping bag. It was much easier to put this 20 F (-7C) sleeping bag (without the extra loft) into the bivy. I still slept with the sleeping pads underneath the bivy as they are not tapered so the lower portion won't fit into the bivy. I also used a plastic ground cloth underneath everything to keep wet forest debris from messing up the whole set-up.

I didn't have any noticeable frost this time, but I did experience an occasional drip of water off the open gap in the zipper when I would lie on my back for a few minutes or turn from one side to the other.

Care, Durability, and the Future

So far, the bivy has held up great. I haven't had to do any maintenance or cleaning but I will monitor that in the long term period. I will continue to use the bivy on several upcoming trips and hope to evaluate its performance as the weather gets a bit warmer. Springtime temperatures will still be very chilly during the nights but shouldn't necessarily be below freezing. The Penguin Bivy will most likely be more exposed to ground vegetation during this time period so I will monitor its durability.


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Long Term Report
Integral Designs Penguin Reflexion Bivy
July 8, 2008

Locations and Conditions

During the long term test period, I have slept in the Penguin bivy every night during two different four-day backpacking trips (total of six nights). Locations ranged from and included conifer and deciduous forest communities with many rock outcroppings to lakeshores and wet swampy areas.
Elevation ranged from 600 ft (183 m) to approximately 1200 ft (366 m).

Early May Backpacking Trip:

Location: North Country Trail - Upper Peninsula of Michigan
Type of Trip: Maintained trail
Distance: 41.3 m (66.5 km)
Length of Trip:
4 days
Backpack Weight: 30 lb (13.6 kg)
Sky and Air Conditions: Cloudy, partly sunny, rain
0.15 in (0.38 cm)
Temperature Range: 34 F (1 C) to 62 F (17 C)

Late May Backpacking Trip:

Location: Fox River Pathway and Lakeshore Trail
Type of Trip: Maintained trail
Distance: 58.25 mi (94 km)
Length of Trip:
4 days
Backpack Weight: 28 lb (12.7 kg)
Sky and Air Conditions: Cloudy, rain, snow
0.50 in (1.27 cm)
Temperature Range: 37 F to 54 F (3 C to 12 C) (mostly 40 F to 45 F/ 4 C to 7 C)

Performance in the Field


After spending a total of thirteen nights in the Penguin Bivy during four different trips in the entire testing period, I have come to several conclusions. The bivy has been perfect for cold weather camping as the manufacturer fully intended. The center zip has been my favorite attribute as it makes it easy to enter and exit the bivy and keep a breathing hole over my face as I turn from side to side. The breathable Sympatex fabric of the bivy is very comfortable, waterproof and is easy to pack. I have stayed warm in the bivy down to temperatures of -4 F (-20 C). I am a cold sleeper so undoubtedly the fabric worked well to transfer my body heat. Although the bivy is plenty roomy in both the chest and hip areas, I do wish the tapered foot end was a bit roomier for my -20 F (-29 C) sleeping bag during the winter months. As mentioned in the field report, I also would like to see ribbon tags on the zipper tabs inside of the bivy to facilitate an easier exit

Long Term Field Conditions

My two four-day backpacking trips during the long term period still had rather low temperatures at night even though it was well into spring. The evening temperatures were not much above freezing. I actually debated whether to pack the bivy during the last trip as it was definitely bug season. The bivy does not have any bug netting as it's intended for cold weather use. Because the lows were expected to be in the 30's F (-1 C) during the evening, I figured the bugs would not be a problem during the night. I was correct and the bivy worked well with the zipper vented to expose my face.

During the trips in this period, I used a full-length ground sheet and only a single Hyper Lite 2/3-length tapered pad underneath the bivy. Although I chose to keep the pad outside of the bivy there was plenty of room for both a three-season sleeping bag and tapered pad without compressing the loft of the sleeping bag. With this arrangement, I didn't have any trouble staying warm. I slept in my trail clothes plus a synthetic-filled vest for extra upper body warmth. I didn't stake the tunnel vent's hanging loop as I prefer to move from side to side and move the bivy with me. This hasn't affected the venting capability as the fabric is stiff enough to still allow function of the vent.

I set up a 9 ft by 9 ft (2.74 m by 2.74 m) tarp in combination with the bivy so that I could have further protection from the weather. Because of the areas where I travel and because I never shop the weather, many nights of all my trips are rain filled or worse. There was light rain one night and heavy rain another night on the first trip. The second trip had heavy-to-medium intensity rain all of the nights. The bivy did experience some spray from the constant rainfall with driving winds but the water didn't penetrate the fabric.

The bivy has continued to function well for breathability. Even with damp rainy weather, the bivy's inner surface has remained mostly dry to the touch and the only areas that felt somewhat damp are those close to my mouth and nose. After many consecutive days in the field and being packed and unpacked everyday, the bivy has stayed dry to the touch.

The bivy is very long. I am only 5 ft 9 in (1.75 m) so there was at least a foot (30.5 cm) of space left at the bottom of the bivy. As aforementioned I would like to see the foot end of the bivy widened a few inches to accommodate a severe cold weather bag such as the one I used in the field test period. Both the chest and hip girth was perfect but the foot end slightly compressed my -20 F (-29 C) bag when I was inside the sleeping bag.

During the long term testing period I packed the bivy in two different backpacks on the last two trips. It doesn't take up much space with the stuff sack provided. However, I do prefer a bigger stuff sack so after the test period I no doubt will use a larger one to make packing simpler in below freezing temps.

Durability and Care

The bivy still looks just like new. There aren't any noticeable defects and the zipper continues to work perfectly. The stitching and taped seams are intact and I fully expect them to remain so over the long haul as I feel that the workmanship on the bivy is superior in quality. The Sympatex fabric has held up well even though it is used for the entire bivy. I did use ground cloth protection after the snow melt.

Overall, I really like the Penguin Bivy. I will continue to use the bivy for many of my outings during non-bug seasons.

  • Center zipper placement
  • Soft non-crinkly material
  • Easy to rotate self with bivy
  • Windproof, waterproof and breathable 

  • Bottom of bivy is very tapered so there isn't much room for a lofty -20 F (-29 C) sleeping bag
  • Zipper ribbon pulls are all on the outside of the bivy
  • No bug netting if used during the summer months

Tester Remarks 

Thanks to Integral Designs and BackpackGearTest for this great opportunity to test the Penguin Bivy. This report concludes the test series. 

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