The construction of the sleeping bag defines how the filling is kept in place and layered inside the bag. This defines how well the filling insulates and ultimately decides in how cold environments the sleeping bag can be used.
The most simple design for a sleeping bag is to use the stitched through construction. Using this method the shell and lining are stitched together directly on top of each other to create the chambers into which the filling is inserted.
The H-box, H-chamber and Box Wall Construction is divided into different chambers with vertical side walls to keep the insulation in place and to avoid cold bridges. This ensures a uniform thickness of insulation all through the sleeping bag.
A slanted wall construction creates a more difficult path for heat to escape along the relatively low-density insulation area against the side wall. This improves the thermal efficiency of the bag even more than H-box construction.
Offset Double Box wall
The two box wall layers, one on top of each other, have their baffle walls offset relative to each other, which creates an appearance similar to that of a brick wall. Often used in bags with a large amount of filling – typically for extreme conditions.
Offset triple box
Offset triple box is basically designed as the Offset Double Box wall construction, but with an extra layer. The third layer adds to the unique insulation by increasing the volume and the temperature level. Best suited for sleeping in extreme cold.
With tubic construction technology a pair of arched insulation fibres runs in a vaulted formation through the entire length of the vertical thermal channels. The added loft traps more air, increases heat distribution and reduces heat escape options. The result is a 3-dimensional loft optimization and higher thermal efficiency.