Steve Seeber

Introduction It seems widely accepted that elevated air permeability (the ease with which ambient air can penetrate jacket fabric) in a lightweight windshirt can provide effective moisture vapor removal during backpacking and hiking.

Introduction This series of articles has taken a detailed look at a variety of aspects of synthetic insulation used for clothing or sleeping bags. In this article, we take a look at the degradation of thermal performance of synthetic insulation that may occur due to normal use of insulated garments.

In part one of this series, we focused on batt-type insulation as well as two knit active insulations. We covered how these insulations are manufactured, their benefits and drawbacks. We covered issues related to how the insulating value of the insulations are measured by the industry. We presented the results of our measurements of thermal resistance for 11 insulation products. In part two, we looked at fleece insulation. We learned that: Fleece is not very warm.