Bob (Dennis-Your question is incorporated in the last paragraph)
I have been up in the Sierras for a few days and am now just getting an opportunity to start responding to questions. First I want to say I was very impressed with your responses to Will's article on "Salomon Tundra Mid WP Insulated Boot Review". Your posts were courteous, well structured, and compelling in the support of your position… great job.
You said, "Can you tell us more about what makes for a better rating"? The fleece and synthetic insulation vendor's clo/oz ratings closely correlated with their relative performance vis-à-vis one another. The down insulation results closely correlated with the down fill amount. All insulations do a good job of blocking convection. Blocking radiation losses is the biggest variable between the synthetic insulation types and as well as the impact of down density. Based on my tests, fleece and synthetic specifications appear to be based on the inclusion of a still air layer on the outside of the insulation in addition to the insulation itself. When layering garments, frequently this still air layer won’t be present and the ensembles won’t be as warm as you would anticipate. Sizing of each layer to have at least a 6mm gap between them is necessary to approach the insulation vendor’s published clo/oz values.
You said, “When a manufacturer comes out with a "new and improved" version next year, how do we know whether or not it still occupies the same place in your table? And if not, then where it belongs?” The situation with garments and sleeping bags in the US is the same as it was with sleeping bags in Europe prior to the EN 13537 standard. In other words the consumers aren’t provided adequate information to make an intelligent decision. I suggest buying from vendors who have a reputation for honest representation of their products specifications and then try and find the closest match to something which has already been independently tested by multiple sources. It is in the interest of most manufactures and their advertising partners to use FUD (fear, uncertainty, and doubt) to discredit the value of independent testing. The only manufacturers who would benefit from having independent tests published are the one who products test best.
You said, “How do I determine where a garment not in your table fits in?” You can extrapolate from the existing test results. For example, in a post subsequent to yours, Dennis Park asked, “By any chance, would you know where Mountain Hardware's Compressor men's jacket would fit on your chart? Oops, forgot to mention 2007 model.” The 2007 Compressor specs were size medium [Weight] 16 oz [Shell] Superlight 15D, [Insulation] PrimaLoft One 115 g/m2. That is the same insulation type and a similar amount to what was used in the WT PL1 hoody that I tested. The Wild Things Primaloft One hoody used 2 layers of 60 g/m2. This jacket would theoretically test out with an intrinsic clo of approximately ~1.46. In other words, it is ~1.5 times warmer than a Polartec 300 weight or a Patagonia Micropuff pullover or jacket.
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