January 12, 2017 - Just announced.
Ventrix in Popular Mechanics' "Outdoor Retailer 2017: The Best New Gear of the Year":
"PM is at the Outdoor Retailer Winter Show in Salt Lake City this week, getting our hands on all the gear that outfit your next adventure.
Built for all-day adventures, the Ventrix's flexible insulation features small perforations that stretch open when you move to vent heat. When you stop to catch your breath, the perforations remain closed to keep you warm."
Via Feed The Habit, a cutaway image showing the Ventrix insulation::
"The North Face is taking things one step further by introducing Ventrix, which makes their active insulation even more breathable. They do this by cutting vertical slits into the insulation. When sitting still, these slits are essentially closed off, but when active, these slits open up to allow more moisture to escape. The design makes complete sense and should take their active insulation to another level of breathability. Ventrix will be available in the Summit L3 Ventrix Hoodie in fall 2017 which features 80g insulation combined with dynamic venting."
Described as: "A synthetic insulated mid layer that features a dynamic venting insulation layer that activates with movement and works in tandem with highly wind-permeable fabrics."
Since increased output goes hand-in-hand with increased motion, The North Face debuts an insulated jacket with venting slits in the synthetic insulation. The Ventrix’s tiny gills remain closed when the fabric is relaxed, but open to release heat when flexed.