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Insulation: A Fraud of Meaningless Measures

Made for the High Street or the Mountains? (Image courtesy of GP-Net)

Synthetic Insulation: Warm ... but compared to what?


This is probably the topic (and there are a few) that, above all others, bothers me most about the outdoor industry. I wrote about this to a colleague over at GP-Net who was doing some work for us on our UL-42 tarp. He's a member of Backpacking Light (I'm not) and posted (as my proxy for the day) some of my concerns on their forum, as I was interested in their take on this matter. Some of what is below is mirrored in that thread. I read through it and found the degree of resignation somewhat depressing. 

We're about to review the Mountain Equipment Rampart Jacket and this topic needed to be addressed. We didn't want to drown that review in a rant by me about insulation, so instead I've written this as a companion post.



Introduction: The High Street is not a Dangerous Place

In winter, I'll see more expensive insulated jackets in one minute on a busy high street than I'll see in a full season in the mountains. In terms of the ratio between serious outdoor types (the ones on the peaks) and high street puffers, the worst offender has to be The North Face. I can't remember the last time I saw some TNF apparel in the mountains (perhaps it's just the lonely routes I take, or the fact that it's over-priced and over-hyped).

The outdoor industry needs to decide who its customers are, or at least offer a range that is certified and tested for mountain use. Are they fashion brands offering a "mountain look" for the high street or are they genuine outdoor brands offering something that will prevent death from exposure when it's all gone pear-shaped on the peaks?

These are two very different things. Synthetic insulation, as far as Scramble is concerned is a safety measure (much like crampons, rope or ice axes), to combat the wet and cold. Little in our opinion is more dangerous than the combination (whether in sequence or all at once) of dreich conditions; wet, bitterly cold with high wind chill. I've been closer to serious hypothermia in these conditions than I ever have in dry, double digit sub zero temperatures. In the UK for example, we don't have glamourous towering peaks, we do offer some seriously wet, stormy, bleak, bitingly cold winter paradises and these conditions are often why people on this cheery island die in the mountains.

Big, Loud and Efficient

Imagine a company wants to buy an office block for their business and rather than being told the square footage of the office space they're told "it's big, really big". You want an amplifier for your speakers? No meaningful technical spec stating X watts RMS at Y ohms for you, instead you get "it's loud, really loud". A new car doesn't do X miles to the gallon, no, it's just "really efficient, trust me".  Well, that's where we are in the outdoor industry and frankly it's a disgrace and a fraud. When it comes to synthetic insulation (down is a little different because ducks and geese are manufactured by nature and their down is quantifiable and reasonably constant) we're given the impression of a meaningful specification but in actuality it's merely a call to prayer: trust us, have faith.  

Why Can't We Answer This Question?

Here are three jackets all with different makes of synthetic insulation:

  • Mountain Equipment’s 2014 Compressor:
    Item Weight = 380g (L) - 60 g/sqm Primaloft Gold Insulation
  • Mountain Equipment’s Rampart:
    Item Weight = 395g (L) - 80 g/sqm of Polarloft Micro Insulation
  • Montane Icarus Lite Jacket:
    Item Weight 430g (size unstated) - 160 g (total) of PrimaLoft Silver ThermoPlume (blown into baffles like down) Insulation

Which of these is the warmest?

The reason we cannot know is because no one knows how each of these synthetic insulations perform (except perhaps the manufacturers). It's not measured, or if it is, it's not disclosed. So marketing departments can just go hog-wild with colourful copy and instead provide the impression of a useful specification and we are left taking their word for it (or not).

For example, it allows Rab to drop (the presumably expensive) Primaloft Gold insulation (60g/sqm) for their own proprietary Stratus (60g/sqm) recycled insulation in their Xenon Jacket. They claim, that even though the jacket (326g L) is 16% lighter than its previous incarnation (the Rab Xenon X Hoodie, 390g) it’s just as warm. They offer no proof, they just state it, so it must be so.

Public Relations in Progress

Let's take a brief look at some of Rab's customer questions and the illuminating responses from Rab:  

Q: How does this compare with the original Xenon X with Primaloft Gold insulation?

A: "Great question! We've been using our recycled Stratus insulation for a while now, and only after being happy with the quality of insulation given in like-for-like weight have we decided to expand the use across more items in our range. You should not notice a difference."

No measurements or data, just trust us and if you die of exposure you should have bought one of our warmer jackets, foolish!

Q: There’s no mention of breathability for the insulation. How does the new insulation compare to the breathability of the old (Primaloft) Gold Active version?

A: "Thanks for reaching out. We don't really focus on breathability when looking at insulation pieces as the emphasis is on trapping heat, not letting it go. Breathability is a measurement of letting sweat out, a cooling function. Thus, we aim to understand and research its insulation properties, as opposed to the breathability properties. The function or performance of the Xenon has not changed, however. It is still an awesome lightweight belay jacket."

Really? So why did you use the more breathable Primaloft Active in the Xenon X? As we pointed out in our Mountain Equipment Compressor review:  

"Clearly Rab think people will climb in their new Xenon X, since they've changed the insulation to Primaloft Active Gold and have made the jacket more breathable. Yet, their own copy states, the Xenon X is "an extremely versatile piece, perfect for everything from a windy belay at your local crag to spindrift belays high in the mountains". So, it's a light Belay Jacket. More breathable means less wind resistant ... but you want wind resistance in a belay jacket. I'm confused."

So now all of a sudden, after changing to a cheaper insulation to keep their profit margins satisfactory, they've decided it's not about breathability. Then why does the jacket have an "under helmet hood with stretch binding"? If it's to go on when not-active, why would they design it so you have to take off your helmet to put it on?  An under-helmet hood suggests wearing the jacket when active, if you put it on when you've stopped being active, you need an over-helmet hood. None of what Rab are saying here makes sense (unless the jacket is designed for sub zero high street conditions), it's just public relations, because they're not being honest about the motivations behind their decisions and the performance of this particular jacket.

All of which indicates why they are unwilling to engage in a tested and certified safety standard for such apparel. Either it's designed for the mountains or the high street, which one is it?

UIAA Standards

“Every construction / design architect / engineer (A/E) knows a material’s R-value is an important factor when specifying insulation products".

Source: Green Building Solutions

So that's the building trade. Why no similar specification when you make insulation for surviving in the mountains? Who would do it? And is it hard to do?

If you're a mountaineer out shopping for rope, you won't find climbing rope quoted as "strong" or "very strong", rather it conforms to a standard. Why? Because your life depends on it:

EN 892 UIAA 101 – "Dynamic rope to be able to take a falling mass of 80kg (55kg on ½ ropes) with a dynamic elongation of 40%, must take 5 falls without breaking ..."

The International Climbing and Mountaineering Federation (UIAA) established the first safety standards for climbing gear.

UIAA CEN certified (Image copyright copyright The UIAA symbol certifying compliance with international standards for safety

The UIAA began creating safety standards in 1960 with the testing of ropes. It has since developed standards for over twenty types of safety equipment, including helmets, harnesses and crampons.

The UIAA collaborates with CEN, the European Committee for Standardization, for the harmonization of standards. In some cases, the UIAA asks for additional tests making the standard stricter than the CEN. Thus, the UIAA standards may differ slightly from CEN standards.

The UIAA drafts testing protocols and standards and independent labs carry out the testing.

So falling and slipping (EN 892 UIAA 101 - Rope, EN 893 UIAA 153 – Crampons, EN 13089 UIAA 152 – Ice tools) and freezing to death in a sleeping bag (EN 13537) are all considered dangerous enough to require testing, standards and certification. But freezing to death on a mountain because you believed the hype from a marketing department whose demographic wants to look chic and outdoorsy as they slide through the high street slush of a winter evening. That's fine.

Copper Man

So, we've found out who could handle the task of testing and certification. Let's now look at what exactly we want to test and how it might be done.

The International Thermal Manikin and Modelling Group published a comprehensive compendium of papers in 2006 called "Thermal Manikins and Modelling" (you can download the PDF here). It's a riveting read. Reading through its pages (or just the contents page for that matter), it's transparently clear that the techniques to accurately test insulated apparel are well established. Ever since General Electric's "Copper Man" (a manikin with a thin copper skin used to test heated flight suits for bombers before pressurised cabins) we've had the ability to accurately test and measure insulated clothing. What is required is a useful benchmark and a sensible testing protocol.

"The first standards based on thermal manikin measurements were developed in the 1980s. In the Nordic countries tests for thermal insulation measurements of sleeping bags and cold protective clothing were developed. Similar standards were published in Germany by DIN and in the US by ASTM. At a European level, EN 342 describes test methods and requirements for cold protective clothing based on manikin measurements. EN 511 describes a method for determining glove insulation using a thermal hand model. In 2005 ASTM published a standard for determining water vapour resistance with a sweating manikin. ISO 9920 already described in 1992 how clothing insulation could be measured with a thermal manikin."

Source: Ingvar Holmér, Thermal Environment Laboratory, Department of Design Sciences Faculty of Engineering, Lund University, Sweden (p. 19, Thermal Manikins and Modelling)

A Simple Benchmarking Test

Ralph Goldman, Chief Scientist at Comfort Technology, points out that for a sensible measure all that is required is a simple test controlling for temperature, humidity, and wind speed:

Image from p.17, Thermal Manikins and Modelling

"While my wife has difficulty believing me (and, at times, I wonder myself), if I want to determine the warmth of these $7,000 fur coats, the model on the right will rave about the beauty and warmth of the coat, but cannot characterize its actual warmth, while the Copper manikin on the left cannot even see the coat but can provide a precise value (second decimal, repeatable from test to test, even two years apart), for the thermal insulation it provides in the form of its measured Clo value.

[...] there are two levels of manikin measurement values. If you are simply comparing the insulation and moisture permeability values of two clothing items (or even of two clothing ensembles), almost any manikin run in a consistent manner at any constant temperature, humidity, and wind speed can be used."

Source: Ralph F. Goldman, Chief Scientist, Comfort Technology, Inc. (p. 17, Thermal Manikins and Modelling)

So, a possible theoretical test might consist of: 

  • A chamber at temperature X, humidity Y and windspeed Z
  • Containing a rotating manikin (so wind is averaged across the jacket's surface) with, for example a 42" chest (standard size large, with hood down if hooded)
  • The thermal manikin might wear a standardised baselayer, hat and gloves

Clo values could be stated (but in my mind these are unintuitive); personally I would prefer a measure based on the time taken for a given temperature drop. For example:

  • You make a standardised, simple hooded down jacket (fill weight = 120g, 90/10, 700 fill power).
  • The thermal manikin is heated to 40°C, the chamber is 0°C, the windspeed = 40mph and relative humidity is 20%.
  • How long before the manikin's temperature drops 5°C (or whatever drop is decided upon as meaningful).

Whatever that number is, that's your benchmark against which all other jackets are measured (perhaps as a % of the baseline / using the baseline as an index). You don't need to confuse people with R-Values, Tog, Clo etc ... You could merely state for example:

  • The ME Compressor (60g/sm Primaloft Gold Insulation) = 70% (or 0.70) EN 9999 (700FP-90/10 Measure)
  • The ME Rampart (80g/sm Polarloft Micro Insulation) = 72% (or 0.72) EN 9999 (700FP-90/10 Measure)
  • The Rab Xenon Jacket (60g/sm Stratus Insulation) = 61% (or 0.61) EN 9999 (700FP-90/10 Measure)
  • The ME Arete Hooded Jacket (116g, 90/10 700 fill power) = 102% (or 1.02) EN 9999 (700FP-90/10 Measure)
    For example, though the insulation spec is lower, a jacket may score higher due to a superior outer fabric, lack of stitched baffles or other design features. In such tests the complete jacket is tested rather than just its insulation.
  • The Crux Pyro Jacket (190g, 90/10 850 fill power) = 120% (or 1.20) EN 9999 (700FP-90/10 Measure)

So, this method helps get away from the age old problem of isolating the insulation. We’re still left with, “well what about the relative humidity and the compression of the down”. But in my mind these are things that people can factor in themselves. Everyone knows that compressing down reduces its effectiveness and likewise soaking wet clumps of down suck at keeping you warm. But such nitpicking is like saying, “the amplifier is not loud enough when I turn my speaker to face the wall”.

In time, customers would come to know how each synthetic insulation compared to a down standard and companies' marketing departments wouldn't be able to say:

"We don't give temperature ratings for our down jackets.  How warm you feel is completely dependent upon your heat output."  - Crux (Plasma Jacket)

Not wishing to pick on Crux here, they make good stuff, but if that statement is true, then why buy one jacket over another. What we're really concerned about is being static (vulnerable to succumbing to the cold), so how did it fare under those conditions? Perhaps it was never tested.

Or "the Pyro features a box-wall baffle construction. This makes the Pyro considerably warmer than jackets with far more down but using stitch-through baffles that leak heat like a colander drains water".  All of which may be true, but you have to buy it first to find out.  You don't have to buy a car to know how fast it can go and you don't have to buy an amplifier to find out how powerful it is - they've been tested and the results are stated in their specs.

Who's Going to Fund This?

One way to fund this would be via a small tax on outdoor brand advertising, since companies like The North Face spend a fortune on giving the impression that their stuff is all about extreme adventures in far flung places (a small part of that marketing budget could go a long way to fund the science to back up their claims), that would put the burden on the big companies and help reduce to a minimum the cost / testing burden on smaller companies like Crux who rely on a hard won reputation and word of mouth to sell their gear.

Final Words

The outdoor industry doesn't seem to want us to be able to make rational decisions (you decide why) and they aren't prioritising our safety in the mountains. There can't be a genuine free market when it comes to insulated jackets, as by definition a free market relies on rational actors making rational decisions. You cannot make a rational decision without quantifiable and comparable information. To do so requires a comprehensible standard measure, a simple testing protocol and accreditation.

It's time insulated jackets, when sold as mountain apparel, were treated like other outdoor safety gear such as sleeping bags and ice axes. Whether you're freezing to death or falling to your death, to quote Hillary Clinton, "what difference, at {that] point, does it make?".


Last Updated: 29/03/20

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