Originally Posted by
MAD777
Yes the geometry would change but, I'm really talking about warmth.
Warmth does not actually relate to loft, but to volume (to a degree).
Let's take an imaginary example: make a quilt out of rigid material such that is is 2" thick.
Now, fill the quilt with enough down to occupy that volume without being compressed.
That quilt will insulate it's occupant like any 2" quilt that we normally think of.
Next, let's double the amount of down in that quilt.
Now we have a quilt with the equivalent of 4" of down in it, but, since it is rigid, it's still only 2" thick.
BUT, it is as warm as a 4" thick quilt.
There are thick scientific papers on this, the best of which was published by Richard Nisley a few years ago.
But the bottom line is that the insulation comes from hindering both convection and conduction.
As a down quilt is compressed, one losses ground while the other gains ground.
According to Richard's testing, the two properties essentially offset each other until the down is compressed about 2.5 times.
So, if the shape of the quilt can be reasonably controlled, which is why we put baffles in,
the warmth of the quilt is a function of the amount of down used, even if it is compressed a little.