Aside from being incredibly warm, puffy jackets don't breath. At all.
That's why you get hot and clammy so quickly. The insulation forms a kind of vapor barrier that locks heat and sweat against your body and in the fibers of the inner jacket lining. Polartec has developed a new breathable insulation called Alpha that allows air exchange and breathability making new puffy pieces, such as SOFs PCU Level 3a a lost more comfortable in a wider range of environments.
The new breathibility comes without compromising the synthetic insulation's ability to provide warmth even when wet. Polartec also says their insulation dries faster than competitors loft insulation products.
Polartec Alpha was developed to meet the performance requirements of the U. S. Special Operations Forces (SOF). SOF required something that was warm, wind resistant, highly durable, quick drying and more breathable than any existing insulation products. Polartec was able to tune the performance characteristics of Alpha to meet the extraordinary demands placed upon clothing by Special Forces Operators. In testing by SOF, Alpha received the highest results of any Polartec product ever tested by the evaluation team. Polartec Alpha jackets are in production and are being fielded to every Special Forces Operator. Alpha is now rolling out to the consumer market and will be introduced at the January 2013 Outdoor Retailer, SIA and ISPO trade shows and available at retail by September 2013.
