Not all vents are created equal. Integrated into all new KJUS ski jacket styles this season, our patented, AC Vent™ technology wins hands down when it comes to keeping skiers cool when activity levels heat up on the mountain. After hours of research and testing in climate chambers and on the mountains of Switzerland we discovered that cooling the inner, lower forearms has the perfect, natural cooling effect on the entire body – so that’s exactly where we put our vent system.
Stay
Cool When Activity Levels Heat Up
Patented KJUS AC Vent™ System integrated into all new ski jacket styles
this winter season.
With the pursuit of technical excellence and optimum wearing experience at the heart of all KJUS product development, KJUS’ patented AC Vent™ system, the first venting system that supports the body’s natural cooling system, has been introduced to all new ski jackets for the Winter 19/20 season.
Extensively tested and scientifically approved in climate chambers and on the mountains in Switzerland, the KJUS AC Vent™ is the most efficient and effective method for alpine skiers to cool the body’s core. The system has been specifically developed to solve the issues that arise when skiers work up a sweat while wearing warm, waterproof clothing that traps moisture inside the clothing. It does this by helping the skier avoid entering the ‘sweat mode’ in the first place – something which can use up to 40-50% of the body’s energy and result in the dreaded ‘post-activity chill’ when under garments become soaked in sweat.
Strategically located on the lower arms of the jacket, near the pulse points of the wrists, the adjustable zippered venting system is optimally located, from a physiology perspective, to allow excess heat and moisture to escape and cool air to enter. When activity levels heat up, skiers simply have to unzip the conveniently located vents on the sleeves to allow the body to balance its overall temperature and avoid entering the ‘sweat zone’. The effect on comfort and performance is immediate.

The reason? The AC Vent™ technology taps into the body’s natural cooling system by enhancing convection – the body’s use of its circulatory system to warm and cool itself. By opening the vents at the wrists and lower forearms where blood vessels run nearest to the skin, the trapped heat can escape quickly and the outside air is able to cool the blood before it is taken from the extremities and circulated back to the body’s core.
The AC Vent not only overcomes thermal stress, which is how physiologists describe heat and perspiration trapped inside a jacket; but also avoids extreme speed cooling. Unlike traditional vents on the torso or under the arms, which can cool the core and the vital organs too quickly and too intensely, the AC Vent™ provides a steady, easily adjustable flow of cool air that cools the entire body effectively, efficiently and safely. The unique position of the vents also takes advantage of the frontal wind that comes into play whilst skiing, which, in combination with the wind chill factor, allows for evaporative cooling. Research in the lab showed that cooling the lower arms and wrists had a significant physiological cooling effect on the entire body especially the high sweat zone of the back.
“Keeping skiers warm is not our greatest challenge. Our greatest challenge is to keep them warm without overheating.” Revealed Ken Kurtzweg, Head of Innovation at KJUS. “Every skier wants to spend less time adjusting apparel because it’s too hot, then too cold, then too hot again – and spend more time actually skiing. The invention of the AC Vent™ system supports this desire by putting skiers in control of their own micro-climate.
He explained: “Ultimately, the AC Vent is founded on the simple, physiological fact that cooling down the inner forearm has a dramatic effect on cooling the entire body. In the same way that in everyday life we naturally pull up our sleeves to cool ourselves down, the AC Vent allows the skier to quickly and easily expose the temperature sensitive inner forearm to the cool air.”
The AC Vent™ is a win not just for comfort but also for performance. When a skier’s clothing is helping them to regulate their body climate, they can spend less energy on thermoregulation and more energy on skiing. Testers’ heart rates were typically 15 beats per minute lower in an AC Vent™ equipped jacket.
Ski jackets this season that feature the AC Vent™ include:
- Men’s: Cuche III, 7SPHERE HYDRO_BOT, 7SPHERE, Freelite, Formula, Formula S.E., Formula DLX, Downforce, Speed Reader, Macun & Boval
- Women’s: Freelite, Varuna, Arina, Ela, Formula, Duana & Laina
Available for purchase at kjus.com, through KJUS brand stores and select retailers.
- Discover more about the science behind the zip: Watch the video
KJUS stands for
sportswear made of innovative, high-performance material with a distinctive,
clean design. The award-winning collections Ski, Golf and Lifestyle are
developed by passionate sports experts and tested by professional athletes. The
company originates from an idea by the Swiss entrepreneur Didi Serena and
Olympic ski champion Lasse Kjus. The two first collaborated to create the first
two-way-stretch ski pants. Their functional garments shook up the market,
setting new standards of performance along the way. The products are designed
to enable sportspeople to focus on the experience. Driven by an enthusiasm for
sports and an uncompromising vision, KJUS continues to push further, innovating
with every seam, fabric and detail.