http://www.ukclimbing.com/articles/page.php?id=5105

I know these subjects are discussed a great deal on BPL. The ideas in this article probably aren't news to most, but I thought that it's a great summary and ties together theory and practice well (with a part 2 to come).

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"In part 1 of this detailed two-stage article outdoor-obsessed boffins Matt Fuller, Dr. Matthew Morrissey and Dr Mark Taylor discuss some of the science surrounding insulation and physiology.

"In part 2 they'll present a brief history of insulated clothing and equipment, look at different materials, describe testing methods used for assessing a garment's warmth and offer some interesting ideas about how clothing might be made warmer in future."

A synthetic belay jacket is a worthy investment. Because of the loft-retaining properties of wet synthetic insulation, their ability to provide the warm human body with the opportunity to dry the layers underneath the insulation is better than with wet down insulation. Because this additional insulation allows for normal or higher than normal skin temperatures, water can evaporate and either leave the clothing system or condense further away from the body where its cooling effect is less pronounced. With no insulation or less effective insulation (such as wet down) the drying of the inner layers would be slower.

darn brits .... dont they understand that my 900 fill down puffy is the only thing ill ever need for ANY conditions ;)

thats the kind of article i would expect from BPL ... but UKC is free =P

But if you look into our archives you will find an article comparing the performance of down and synthetics; how fast they wet out and how fast they dry. Turns out that good down does better than the synthetics.

Cheers

are ya absolutely sure about that in all situations

cause i will tell you personally that thicker down coats do not dry as fast as thicker synth ones ... and same with bags ... especially at higher humidity and lower temps without that shiny orb in the sky

or maybe the brits and every climber in wet coastal environments are doing it wrong ;)

To nitpick, this statement from the UKC article is also untrue/misleading:

"Thickness is roughly equivalent to warmth. Two sleeping bags can easily be compared 'by hand' by judging their thicknesses: the thicker one is likely to be warmer."

Here are some good BPL articles on the subject matter (am I missing any?):

http://www.backpackinglight.com/cgi-bin/backpackinglight/insulation_measurement.html

http://www.backpackinglight.com/cgi-bin/backpackinglight/comfort_moisture_transport_wool_synthetic_clothing.html

http://www.backpackinglight.com/cgi-bin/backpackinglight/wet_weather_performance_down_vs_synth_vests.html

Edited by brawa on 12/18/2012 15:34:19 MST.

BPL believed that for the longest time ... they used to look at the loft of the bag and make comparisons based on that ...

till someone pointed out that the weight and quality of down fill is more accurate

and that EN-testing is the most "accurate" of the current generally available methods ... yet there were still a bit of "whatever" in some BPL review articles about en-testing

Decent article but the most important piece of info I found was a link:

http://www.eat.lth.se/fileadmin/eat/Termisk_miljoe/IREQ2009ver4_2.html

Richard Nisley better find a new day job...oh wait we never paid him in the forums in the first place, at least now he can provide a link instead of doing the calcs himself.