[bborud]

Gore Tex is a good example of a material that, on its own, doesn't actually work as well as the marketing would have you believe. For instance it stops breathing when it gets wet. And then the whole rationale is gone. It means your perspiration condenses on the inside and then you become wet and cold. Most gore-tex jackets will not even work for my bicycle commute since it rains all the time here. Much less riding my bike in the forests or mountains.

Technical garments are not just down to what materials are used, but how the garment is designed to manage moisture and heat, and how you combine it with other garments and reconfigure it as needed.

I spend a lot of time outside in anything from heavy rain to -25C cold. Often in stormy conditions. I often engage in prolonged physical activity, which means I perspirate a lot. Often followed by rests. If you do not dress properly, so you can manage moisture and heat, best case is that your jacket will start to smell like a homeless dog. Worst case, you freeze to death (yes, that happens when tourists don't know how clothes work).

If there is any miracle material it is wool. No synthetic material even comes close. But then again, that's not an outer layer. It's what you wear for the inner and middle layers. And it does that job unreasonably well.

[seec]

Couldn't agree more about Gore tex. It's mostly marketing genius. On the surface it does what it says, in practice it won't work as you expect it. In the end it's kind of useless, especially considering the price. But the marketing is so well done, that people swear by it, even though for the supposed purpose of the garment, there are far better and cheaper solutions.

[fingerlocks]

It’s much more efficient to wear the densest layers closer to your body, because that’s less volume to keep warm. Most people wear wool, synthetic, or a down coat underneath the goretex.

Try doing the opposite and see it how it works. Puffy outside the goretex. This only works on very cold weather. If it’s raining it’s too warm.

Mark Twight tried to popularize this idea but it never gained popularity despite how efficient it is

[bborud]

Perhaps it works if you are not physically active. But it is quite the opposite of what people do in cold regions.

The inner layers are usually the most important ones. The inner layer needs to do two things: transport moisture away from the skin and maintain a continuous layer of air close to the skin for insulation. It also needs to reduce skin contact points if you perspirate a lot.

Wearing dense layers close to your body would interfere with moisture management and heat distribution.

If you look at how Norwegian soldiers have dressed for winter exercises over the last 100 or so years, the inner layers will usually be a string/mesh undergarment. This holds a continuous layer of still air against the skin while minimizing fabric contact points. The holes allow sweat vapor to escape to the next layer, which then handles the transport of moisture. The second layer is usually a somewhat dense weave, relatively thin wool layer. Synthetics lose their insulating ability when they get wet/moist. Followed by a looser knit, thicker wool sweater. With a wind- and water proof uniform jacket as the outermost layer. This essentially creates two layers of air separated by a moisture transport layer.

The mesh garments were traditionally made of cotton, which is usually not a material you want next to skin, but it works in mesh form. Non-mesh cotton garments are terrible next to your skin because they get wet and then lose their insulating properties and stick to skin drawing off heat. If you sweat and then keep still for a while you will get cold and it feels wet and miserable. Wool doesn't have this problem as it keeps insulating even when wet. (Roughly the same cotton mesh garment, from the same manufacturer, that I wore in the military, was also worn by Tenzing and Hillary during their ascent to Mt. Everest in 1953).

You can get pretty good mesh garments today made from wool that also cover your arms. This is kind of the secret trick to staying warm and dry in polar conditions.

The configuration I wear most days is just light, thin, loose merino wool inner layer, thin, dense wool second layer and then a hard-shell. I started wearing this because I commute to work on my bike all year round, and I needed something that manages moisture, keeps me warm and doesn't smell. When it gets colder I add a cotton shirt or a loose knit sweater.

If it gets really cold (below -25) I usually drop the third layer and wear a down jacket (the kind climbers use on expeditions), but this has no vents so it doesn't work if it is warmer than -25C -- it gets too hot. If it drops below -30C I add a wool sweater. (The down jacket is overkill for where I live, so I use it perhaps 2-3 times per year)

[fingerlocks]

I couldn’t get past your first sentence. The person that promoting dense-first layers is probably the most influential and famous Alpinist ice/rock/mountain climbers to have ever lived. The man is known for doing his research.

[bborud]

And yet, this isn’t what what people in polar regions do. Nor is it how professionals are taught to dress in cold climates.

Reinhold Messner believes in yetis. Linus Pauling thought you could cure a cold with vitamin C and shot coffee up his ass. Clever people believe in dumb shit too sometimes.

Perhaps you should read the manual for how armies that operate polar regions dress? Or perhaps get some first hand experience before you insist?

[fingerlocks]

Physics is not on your side. You need more energy to heat up a larger thermal mass. Dense layers closer to the bodies core reduces the total volume.

[bborud]

I don't think you have chosen the correct physical model for insulation. Insulation is about thermal resistance, not minimizing mass.

Your body is continuously producing heat. What matters for staying warm is how fast you lose that heat, not how much “extra fabric” you have to warm up. The thermal mass of clothing is tiny compared to the thermal mass of your body so it isn't numerically relevant. The limiting factor is heat loss to the environment.

In clothing insulation comes from dead air space and preventing convection and conduction. Down jackets are warm because they trap a large amount of air in place and create a very gradual temperature gradient. That is, it spreads the temperature drop out over a thick, fluffy layer, so the inner surface stays close to skin temperature and the outer surface closer to ambient. The result is a much lower heat flux for the same inside–outside temperature difference. (A better mental model of this is that you have two boundary layers separated by a gradient that keeps ΔT low at each boundary layer. We know that heat flux is linearly proportional to ΔT)

Of course, clothing adds another dimension of complexity that is critical for comfort and survival: it has to deal with how your body actively regulates temperature: by perspiration. That is: you have to manage moisture too. And quite possibly a lot of it if you are active.

Wet fabric has higher thermal conductivity. Worse still, if it is dense and gets stuck to your skin you get very efficient direct heat transfer. The thing we want to avoid.

Think about why it is important to have a good thermal paste layer between CPU and heatsink. Now imagine you place the heatsink on a 0.1mm layer of aerogel. Do you think the latter configuration will cool the CPU efficiently?

When metabolic heat production drops that wet, conductive layer becomes a heat sink and you chill rapidly. In cold environments this can happen fast and be lethal.

[fouc]

I have a long-sleeved polypropylene shirt from the 1980s that I still wear for hiking. It's not scratchy, never smells, keeps me warm, dries quick. It was probably made by a Switzerland company, they knew how to make good quality clothing.