KLIM - Breathability vs. Air Permeability

Breathability vs. Air Permeability

Every year it comes up. Videos, forum rants and in-store displays showing bubbles of pressurized air moving through a membrane are credited as dynamic proof of superior breathability in an outerwear fabric. However, the facts remain the same; Air Permeability—the movement of air molecules through a membrane under pressure—is NOT breathability. In fact, they couldn’t be further from each other.

The only thing pressurized bubbling displays show is an inferior weatherproof membrane’s ineffectiveness at blocking wind from chilling your body. Unless you’re pumping up your jacket with an air compressor and want wind to hit your skin, don’t believe the hype surrounding these “breathability” displays.

Here are the facts on breathability, waterproofness, air permeability and real technical riding gear.

No room for compromise
Blocking moisture and the elements from the outside while simultaneously encouraging perspiration to move off your skin and out of your riding gear will keep you warmer, drier and more comfortable every time you ride.

KLIM and GORE-TEX® (and only KLIM and GORE-TEX®) have developed snowmobile-specific fabrics and construction techniques over more than 10 years to ensure every ride in KLIM is GUARANTEED TO KEEP YOU DRY®. This is done through the potent combination of Durable Waterproofness, Supreme Breathability, Durability (toughness) and Windproofness. If you sacrifice in any of these areas in your riding gear, your overall comfort and vulnerability to the elements will suffer.

KLIM and GORE-TEX® beat all others when it comes to maximizing all points of performance:

But the bubbles look so breathable…
We know, it seems like it makes sense. But what you’re seeing in a display that pumps air through a membrane is airflow, air-permeability and lack of windproofness, that’s all.

A truly technical fabric can and will be supremely breathable and windproof. How? Well, it’s because breathability works by diffusion (think spraying perfume in one corner of the room, and eventually the smell fills the room). Water vapor wants to go from high concentration (inside the garment) to low concentration (outside the garment) -- and molecular forces drive this, not air pressure.

In contrast, when wind hits a garment, it needs significant air pressure to push through the membrane (there is no concentration gradient as air is on both sides). If the path for that wind is tortuous enough (like through a KLIM GORE-TEX® membrane), it loses so much energy along the way that it can't make it through...That’s Pressure Flow vs. Diffusion 101, folks.

Again, unless you want wind to penetrate your garments and plan on taking an air compressor on your next ride to inflate your gear enough to create the necessary pressure, a bubbling display is very non-relevant to any riding or laboratory situation your gear will ever come in contact with.

Athletes and recreationists in winter conditions don’t want air permeability or unreliable waterproofness.  
Air permeability is simply when air can flow through a fabric or membrane. On top of supreme breathability, KLIM’s GORE-TEX® construction maintains 100% durable Waterproofness and Windproofness, providing the best outerwear performance available without compromise.

Breathability is Not Airflow
Airflow should be thought of as ventilation and needs to be under your control at all times. Here are some really gross reasons why you should be in charge of how much air passes through your gear:
In one hour of activity the human body produces:

¼ cup of sweat when at rest.
One Pint during moderate activity.
1-1.5 quarts during heavy activity.
Hands dump out 10ml per hour during moderate activity (casual riding)
Feet expel 25ml per hour in the same conditions. These numbers can DOUBLE during high activity.

Clearly, there is a lot of moisture coming out of your body at all times. And that amount increases as you heat up through activity.

Windchill Is Serious
At 20 degrees air temperature with a 10 mph wind, the Windchill Temperature drops to a bone-chilling 2 degrees. At 10 degrees with the same wind speed the Windchill Temp plummets to -9 degrees. There’s a reason meteorologists on the news talk about Windchill. Don’t compromise your safety or comfort. With KLIM’s clothing systems, you can be sure you’re covered in all conditions.

Intelligent Ventilation is Your Friend
KLIM gear is engineered with max flow ventilation to counteract the high sweat rates and body temps of extremely active riders. By ventilating at the right time, riders can expel overheated air and get their body temps normalized quickly. Maintaining a proper core temp is ideal and being able to control the flow of cool air is highly important.

KLIM’s GORE-TEX® Outerwear has no compromise. 
KLIM designs gear for real world extremes that the world’s best snowmobilers deal with on every ride. It is guaranteed to be durably waterproof, completely windproof and supremely breathable keeping you dry and comfortable at all times. It truly is the best of all worlds. It is gear built without compromise.

Learn more about KLIM gear by visiting your local KLIM dealer or by logging on to www.KLIM.com