Wool as an Insulation

A Resurrected Insulating Material: Wool

Wool has a reputation as an insulating material for several hundred years because even if it gets wet the wool fibers will not collapse the way cotton fibers do or as down does. Therefore since the bulk of the fiber remains basically constant the wool garment will retain some heat or have heat retention property.However, the fact that the wool does retain the moisture that it has absorbed and that moisture does absorb the heat produced by the person wearing the garment. The heat absorption is slower than if you are wearing a cotton garment but it is taking place.

The Smartwool Company isn’t satisfied making good socks so they are now entering the market place with outerwear garments that contain wool and polyester fiber blend batting. The wool portion and I quote is “75% and the polyester portion is 25%”. The weight of their battings is 60 and 120 grams respectively. When you convert grams to ounces you get 2.11 ounces and 4.23 ounces. What I do not know is if the weights are per square yard (36x36 inches or linea yard (36x60 inches), however it really does not make a difference. Neither will give much effect insulation below 45 degrees. The thickness is not much different than what companies like Patagonia and North Face have been selling for two years. The opening sentence of their published literature is and I quote; “Ultimate warmth starts at the core”. I have no idea exactly what this sentence means. With regards to the specific garment I have been reading about “Women’s Corbet120 Vest” the 120 references the weight of the insulation and I quote “SmartLoft 120” which is what they call their insulation. Here again I quote from their literature “Warmer weight (120g) SmartLoft wool insulation for stop-and-go alpine endeavors in cold to extreme conditions. Provides thermoregulation and warmth even when wet”.

When reading their literature I recommend wearing chest waders because it gets deep. You might also want to have a shovel handy. “Thermoregulation” is keeping your body temperature steady regardless of the external temperature. Garments made with this wool/polyester blend of fibers of these weights will not do that. As a matter of fact wearing this garment in the conditions expressed in their literature will cause you to become cold. The source of heat in the human body as in all living creatures comes from the fuel that is consumed i.e. food. Activity increases the rate of metabolism faster than when we are at rest. Once the fuel has been depleted we no longer produce heat so the core temperature of the body diminishes and it can happen very quickly if the clothing you are wearing is less than adequate. This garment is less than adequate in extreme conditions. (But, of course if you were to wear a Wiggy’s Antarctic parka over the vest you would be fine.:) Like all of the companies out there these days they do not qualify how it is possible to actually be comfortable while wearing one of their garments. In my opinion this is, can be, and in some instances has shown itself to be dangerous to the wearer of the garment.

The moisture that is trapped in the wool is not only what has been absorbed by the wool but that which is trapped along the quilt stitch lines. The fiber has been pulled via the stitching very close together to eliminate the thickness and the moisture is trapped there. The history of quilted polyester has demonstrated this action for almost 60 years. The polyester does not absorb the moisture as wool does, but the stitch lines do trap the moisture regardless.

I have been doing work with wool battings for a few years now and the companies I do the work for do not make outlandish claims about the wool batting being used in “extreme” conditions. It does have a nice soft hand and it drapes very well. I remember when I first started selling insulations we had a wool insulation material that was sold to ladies coat manufacturers because of how nicely it would drape. The coats were dress coats not coats made for going into the woods.

Companies like Smartwool are trading on their name which in the sock market place is exemplary but as for insulated clothing they leave a lot to be desired. If one is purchasing one of these garments because of the fact that it is fashionable go for it. However, if you are to believe the published literature and buy it for that reason, you are simply deluding yourself.

One should never forget that moisture IS the number one absorber of heat on the planet. Moisture will always absorb heat from whatever the source is and if it happens to be the human body in a cold environment the moisture doesn’t know the difference it just takes the heat. When people call me telling me they were cold in this or that situation the reason always boils down to the same thing, retention of moisture next to their body and the fact that the layers of clothing are retaining the moisture enhances the absorption of heat away from the body more efficiently.

Companies such as Smartwool, Patagonia, North Face, Arc’teryx, Columbia Sportswear and so many other companies in the outdoor industry talk about moisture management as if it can actually be accomplished. What they do not talk about is how that can be accomplished other than to say they are making garments that will “wick” the moisture away from you. Unfortunately those in charge of making these garments rely on the fabric mills to tell them what fabrics they have that will do for them what they want. They do not do their own investigation to see which fabric will do what. Of course the people working in sales at the mills do not have a clue either. So what we have here is the blind leading the blind.

The end result is simple; the ultimate consumer of products sold by these companies do not get any garments that “wick” moisture unless they are made from cotton, silk, rayon or WOOL. These fibers are the only fibers that can “wick” moisture. The synthetics regardless of how much of their special finishes are applied DO NOT WICK. They trap and retain the moisture insuring that the person wearing these garments gets a chill.

Like I said earlier in the article, if you are into fashion and find these garments fashionable buy them, but do not fool you into thinking they will perform as the company literature states.