The down is very fluffy. It expands to fill the space. Almost like gas in a container. See this video to better understand: ua-cam.com/video/UTTLDl_Y98U/v-deo.html This keeps it distributed throughout the chamber, if you have enough that it fills the whole space and still retains a little bit of "pressure."
How do you prevent the down from bunching up to either end of the sleeping bag? Seems like it would all go to your feet
The down is very fluffy. It expands to fill the space. Almost like gas in a container. See this video to better understand: ua-cam.com/video/UTTLDl_Y98U/v-deo.html
This keeps it distributed throughout the chamber, if you have enough that it fills the whole space and still retains a little bit of "pressure."