The SOL Escape Bivvy

[Richard Nisley]

Executive Summary: This bivy's tests matched the lofty claims of the manufacturer.

We owe Brett Peugh a “Thank You” for initiating this project and sending a sample to test.

Specifications
The product description says “The SOL Escape Bivvy is nothing less than a revolution in backcountry shelters. The complaint with most ultralight emergency shelters is the same: condensation builds up inside as you get warm, leaving your clothes soaking wet. With the Escape Bivvy, condensation is no longer an issue, and you never again have to choose between staying dry and staying warm. The proprietary fabric lets moisture escape at the same time that it keeps rain, snow, and wind on the outside – all while reflecting your body heat back to you.”

-Available on Amazon for $32
-Made of spun-bonded olefin
-Dimensions of 84” x36”
-Listed weight of 8.1 oz.

Initial Impressions
I was sent a 13” x 16” wedge sized sample from the hood area of a used orange bivy. It looked as it was stuffed many times do to the myriad crease lines. None the less, there weren’t any visible cuts or abrasions. The outer 1” hood seam was made of rip-stop nylon and was sewn to the bivy with two parallel seam lines. The limited sample size showed professional construction.

It looked like aluminized Tyvek Type 10 but with the normal white side, orange for the bivy implementation. I found a lot of subjective reviews on the product but I was unable to find any source that had objectively measured the products characteristics.

Thickness and Areal Density
The material measured a nominal thickness of .0087 inches (.220 mm) and a basis weight of 83 g/m2 (2.45 oz/yd2).

Micrograph Analysis
I first put in under a microscope to determine its makeup. The micrographs indicate that a regularly perforated orange film is laminated to a spun-bond layer. The spun-bond layer is coated with aluminum opposite the side laminated to the perforated film.

5.0 mm field of view showing the orange side

1.5 mm field of view showing the orange side

5.0 mm field of view showing the silver side

1.5 mm field of view showing the silver side

Hydrostatic Head Analysis
The small pores in the spun bond side act as an efficient hydrostatic head barrier. The material tested 1,336 mm H2O. The international standard for being considered rain proof is 1,500 mm H2O. Most cottage manufactures in the US, including more major players like Golite, average only 1,200 mm. Like all air permeable material, once the hydrostatic threshold is passed, the water in the pores will act as capillaries and subsequent leakage will occur at a lower hydrostatic head.

Air Permeability Analysis
The material averages an air permeability of .67 CFM. In contrast the most breathable version of eVent achieves only .5 CFM. Condensation avoidance should be comparable to eVent.

Emissivity Analysis
I tested the aluminized surface’s electrical conductivity across six wide areas and it was infinity for all tests. This indicates that, in spite of the obvious prior use, the aluminum layer remains protected from abrasion and oxidation by a non-conductive surface material. The Mylar layer, used on the most recent aluminized Cuben, had an emissivity of .4; as a result, the aluminum could not achieve it potential reflectivity. In contrast, this material is coated with a very thin layer of lacquer (acrylic polymer or copolymer) with sufficient thickness to provide effective anti-corrosion protection to the metallized layer while providing an emissivity reading of no more than .04 (100x better than Mylar).

Best Case Insulation Provided
When installed with an air-space, the metallic surface provides thermal management which provides the bivy’ s effective R-value up to R-2 as shown in detail below:
1. There is a single metallic surface that has an emissivity of .2 as measured by ASTM C1371-04 a Standard Method for Determination of Emittance of Materials Near Room Temperature Using Portable Emissometers.
2. The metallic surface shall be installed facing a clear airspace created by the bivy use.
3. Effective R-value is calculated based on the method detailed in Chapter 24 of the ASHRAE Handbook of Fundamentals as shown in the graph below:

I used the EN13537 standard for determining the lower limit (LL) temperature rating of 66.5F for the best case air space scenario.

[J Mag]

I want to hug you so much right now Richard but from your profile picture I would assume you would be adverse to the idea and very hairy.

I have been looking into adapting one of these as a peapod/ underquilt setup for a hammock and really needed this info to get an idea on the feasibility.

Thanks

[TKB 1979]

I just bought one. :)

[Ozzy McKinney]

My wife was looking at me with the "I might call the men in white coats" look as excitedly babbled over this.

Straight jackets be damned, this was just all kinds of cool, and I thank you sir for your contribution.

[TKB 1979]

No offense – I'm new to the site – but who is Brett Peugh?

[Richard Nisley]

Brett is a forum member who took the initiative because he believed it would be a topic of broad interest.

[TKB 1979]

Got it. Thank you, sir.

[Mitchell Ebbott]

Wow, excellent information! Does anyone have an estimate from that R-value of the lower thresholds of comfort and safety?

By the way, it seems that the 5.5oz Escape Lite version is the same material, only slightly smaller (32" x 82" vs. 36" x 84") and without a zipper.

[Richard Nisley]

Mitchell,

Per the last sentence in the original post:

I used the EN13537 standard for determining the lower limit (LL) temperature rating of 66.5F for the best case air space scenario.

[Joe S]

I've been waiting for someone to test this, much thanks. Very interesting results. This could be a winner.

[Seth R]

Would love to try this with a tarp as a summer ultralight setup. I'm a skinny guy and 36" across seems really tight.

[J Mag]

A 72" circumference is really tight? I don't think so…

If your shoulders are over 2 ft wide you should look into bodybuilding.

[Diane Pinkers]

I love the fact that Richard has the skills to dig in and test a product to find out if it works as described–get beyond all the marketing hype. But, what does all this mean? I am not enough of a physics geek to interpret. Is there an old post somewhere that details what each piece means? Or, an outside resource that breaks it down for non-engineer/physicist crew? Or, is there a summary–yes, this works as claimed, nope, this sucker will still get you wet due to condensation?

Thanks!

[Art …]

so if I dumb Richard's analysis down a bit we are saying :

this product has good insulation value,
is highly breathable,
is not quite water proof but is highly water resistant,
and is cheap ?

is that right ?

[Rick M]

del

[James Marco]

Thanks, Richard!

I don't thnk it would hold up too well in the ADK's, the rest of the North east and north west. But it looks pretty good for dryer areas as a shelter/bivy. In cold temps it looks pretty good indeed. Venting becomes very important at less than 40F. Especially if you happen to get warm while sleeping.

[marcelo mora]

I used this bivy alone with a grand trunk hammock as a blanket sometimes. I spent 19 nights in Olympic national park in August last year. The nights where we were in seven lakes Basin I was cold. I also had terrible clothing and no jacket. This was at the point where I really wanted to be a ul backpacker but had no money but just the dream of seeing the outdoors and to finally see Olympic. This bivy let me do it :)

[Richard Nisley]

Diane,

Yes this product works as claimed (smile).

[Seth R]

"A 72" circumference is really tight? I don't think so…

If your shoulders are over 2 ft wide you should look into bodybuilding."

I knew there was something I was missing. Thanks.

[Dale Wambaugh]

Great info, Richard, and thank you.

Now, how are we going to use this thing?

My first inclination would be to use if for day hiking emergency backup, but it isn't waterproof enough for me to use a a stand-alone bivy. It could be used under a poncho or other minimalist tarp shelter. At best I would expect it to protect from wind and light precipitation.

For multi-day hikes, it could be used like any bivy to protect from splash when used in conjunction basic tarp shelters or a dew/wind barrier when sleeping without a shelter.

I think it is weak on breathability and water resistance and rather heavy and expensive for a backup emergency bivy at 8 ounces and $50. I looked at these closely when they first came out and opted for the AMK Heatsheet bivy at 2.40z and $17. The Heatsheet version is not at all breathable, but it is fully waterproof. My strategy is to use it with a poncho for emergency shelter.

Any bivy that is a simple shell is going to provide the same sort of protection that a windshirt or rain shell would, but covering head to toe. It will block wind and precipitation, with waterproofness and breathability varying just like the garment shells. If you want warmth past that, you need loft and some sort of ground insulation. In the emergency scenario, that means my clothing and whatever I can improvise for ground insulation. The bottom line is that it could be an uncomfortable night, but I would survive to complain about it.

If you are thinking about using one of these things as a regular part of your shelter system, I think it would be a waste of money. I recommend spending a little more and getting a true bivy with an integrated bug net, waterproof bottom and breathable/water resistant top fabric. For example, a TiGoat Ptarmigan bivy with the the bug net option is 6oz and $120. That is a far better product in terms of durability, performance, weight and versatility than the AMK version.

If you are only going to carry one for day hike CYA/emergency use, get the Heatsheet version.

[Richard Nisley]

Art,

You are substantially correct (smile). To further clarify terms, waterproof always needs to have a pressure specified or implied to be relevant. The Hydrostatic Head test specification tells how much water pressure can be exerted on the fabric before it leaks. A pressure specification tells us how much water pressure will be actually exerted in a specific scenario. If a pressure is less than the measured hydrostatic head, then for this specific scenario we can say it is waterproof.

-This bivy is rain-proof for most cases; the pressure of falling rain (typical maximum 4mm diameter drops at terminal velocity) will not penetrate it. It is comparably rain-proof to typical UL tents by cottage manufacturers (they average only 1,200 mm HH versus 1,336 for this bivy).

These are the pressures exerted by my specific body:

-It would be waterproof if I lay on my side (232.07 pressure versus 1,336 hydrostatic head)

-It would be waterproof if I lay on my back (119.35 pressure versus 1,336 hydrostatic head)

-It would NOT be waterproof if I keeled on it (12953.52 pressure versus 1,336 hydrostatic head)

-It would NOT be waterproof if I sat on it (2428.79 pressure versus 1,336 hydrostatic head)

[Anonymous]

"Hmm, I'd say it is about as insulative as a cotton sheet at body contact points, breathes like wax paper, will wet thru on body contact points, and is kinda expensive compared to a $2 Mylar "space blanket and $5 sheet of Tyvek!"

I'm not sure exactly how a typical cotton sheet would compare to this bivy insulation wise, but at 66.5F, that's usually what i use to stay warm in my house, though i do tend to be warmer sleeper than average. In the winter time, i try to keep the heat down to around 60 (usually fails because wife or others will jack it up), and at that point i throw on a thin Alpaca/Merino blanket as well. Occasionally in the spring or fall, i will throw the latter on as well.

In any case, at 50 dollars, not so sure i would buy it myself. It might be good for some specialized conditions, and unlike typical insulation, even synthetic, it will provide more consistent/reliable insulation in truly "oh shite" conditions.

I wonder how a thinner, needle punctured Evazote foam layered in highly water resistant fabric would compare to the Escape Bivy in terms of insulation in oh crap conditions? Obviously, the foam would pack a lot bulkier and be a bit heavier, but might provide more truly useful insulation?

[Jolly Green Giant]

Richard, you remind me of this scene from Ferris Bueller:

[James holden]

The blizzard weights more of course and may not be as "breathable"

But it is tested to 8 togs, which is roughly a 40F rating

That will keep you alive

Im not convinced "breathable" is best in a survival situation … The VBL effect may be desired in such cases

I personally carry the 4oz heat sheet bivy on long summer rock climbs

;)

[Brett Peugh]

I ma Brett Peugh and it took me forever to get a sample from them. They sent me half of a bag cut lengthwise. I wish they made sheets of this stuff.

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