I definatly agree w/ michael - if this is correct, the results impications are huge for our wallets.
Also, I appreciate the info you post here and really respect the effort you make to answer questions resulting from it. I wonder if it is difficult to post anything new since it means you will be swamped w/ questions (in addition to keeping up with questions from old threads).
With restect to the study you summarized....
I estimate that a mummy bag filled with 22oz of 800fp would be comfort rated to ~15F and thus have an average clo of ~8. Maybe the comfort temp is a little lower and/or the clo a little higher but the point I am getting at is, imo, the (+/-).1clo/50fp should only apply to the clos from the study. It is the % change in clo that would translate to other situations.
Now back on the results / conclusions from the study(ies)... I do have my doubts. Have you done any of your guarded hot plate testing, explicitly, fp effect on clo. I did find a posting you made (from the spectacular "A New Paradigm...") comparing guarded plate results for the MH subzero and MB Alpine jackets (see your post @03/20/2009 23:04:04 MDT ):
here you say:
"my laboratory tests showed that the MH Sub Zero jacket with 9.2 oz of 650 fill down was approximately 20% warmer than the MB Alpine jacket with 6 oz of 800 fill down."
to me this implies the Alpine would require ~20% more down to achieve equal warmth for a total of 7.2oz of 800fp. Also, if the Subzero contained 7.2oz of 650fp would be it would be about ~78% as warm as the Alpine with 7.2oz of 800fp. This is, of course, assuming same coverage of each jacket.
Now I know there are a lot of other things going on here (differt shell, down is probably fp tested to different standarts,...) but your testing appears to imply that the %change clo/fp is much larger than the study you summarized.
Are you able to resolve these two (maybe I am just missing something).
Also, sorry for dragging up something you posted over a year ago. I understand it is pretty tedious to try to keep up with all of this and understand if you don't have time/patience to go thru it
Edited to change 600 to 650 for the Subzero fp