ideas for testing down insulation’s reaction to water/humidity?

[Craig Delger]

I am interested in any ideas you have for "real world" testing for untreated down compared to the latest batch of hydrophobic down solutions (DriDown, DownTek, Encapsil, Quix Down, etc).

I'll buy the jackets and sacrifice them in order to do the tests.

Here is our first test using untreated down in direct contact with water…. we were very surprised by the results.

http://youtu.be/pDx14xueEJA

I have some additional tests in the works right now, but any ideas for future tests would be appreciated.

Thanks,

Craig

[Mike V]

Craig,
You could test down in a large cigar humidor to compare measured humidity effects on different down samples. For applications such as sleeping bags, the bigger issue is extended exposure to humidity as opposed to direct contact with water. It may also be interesting to weigh the down to measure how much moisture is absorbed at different time intervals.

[Craig Delger]

Mike,

we are playing around right now with what you suggested testing down using 70 degrees Fahrenheit and 65% humidity… stay tuned for that. That doesn't take into consideration how the shell fabric and jacket construction impacts the results. The challenge with testing the entire jacket is taking the shell fabric out of the weight gain equation because the shell fabric holds onto moisture as well.

Craig

[Jerry Adams]

Easier to make test samples that are square, maybe a foot or two wide. You can weigh it, measure loft, test it easier.

Maybe the shell fabric is key, but you have to construct some test and do it. You can always expand what you're testing infinitely, but you have to bound it somewhere. You can always test something else in the future.

[Colin Krusor]

Do you plan to test intact jackets or just pouches of down extracted from jackets?

You say your aim is to do "real world" testing. By this I assume you mean you want to do your testing under real conditions outdoors. Tests in a humidor or other enclosure, with controlled temperature and humidity, is not "real world" testing.

The problem with real world testing is that the testing conditions are not controllable. It's hard to compare results for different jackets if they were worn by different people during the tests, or by the same person at different times. This kind of test is only valid if you control for the differences in conditions by testing each jacket many times. If you do that, and make your measurements (of garment weight, loft, internal humidity and temperature, etc.) the same way every time, you can minimize the variance and the effects of confounding factors.

If you don't actually want to do "real world" testing, you could construct a temperature and humidity controlled enclosure and get much more reliable results with a smaller number of replicates. Your experimental set-up can be realistic, and do a fair job of simulating real-world conditions. A dummy that perspires at a controllable rate would not be difficult to fabricate from a manniquin and a peristaltic pump, and an old upright freezer could be modified to simulate any climate conditions you choose. It would be a much larger investment in time and money than just getting a couple of people to wear the jackets outside, but you'd have a lot more confidence in your data.

[Mary D]

What I'd like to see is how the treatment for the hydrophobic down holds up to multiple washings. Neither the sellers nor anyone else has mentioned that aspect.

[Craig Delger]

Mary – great idea. We will test that for you. Ordering up some products that use DriDown and DownTek right now. Stay tuned. ;)

Craig

[Dustin Short]

Put the jackets over a bowl of hot water and have an ice pack suspended just above the jacket. That's as close to real world as you can get without getting wet and cold. The hot water (in an insulated bowl or heated by a hot plate) would perspire similar to a human sweating and the (dry)ice block above would create a sufficiently cold environment to get the water to condense within the garment. Due to phase change peculiarities you'd also have pretty consistent heat/cold surface temps between experiments regardless of ambient temperature.

After a certain time period you can measure loss of loft (a noisy and imprecise measurement) or weight gain due to moisture absorption (assume if hydrophobic should be minimal and compare with synth and normal down insulations).

Direct measurements of thermal conductivity may be more difficult though. You'd have to shield the cold side thermometer from being skewed by the cold "source" of ice.

ICE-ICE-BABY-ICE-ICE
|| air gap
||

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||***DOWN******
||

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|| hot water
||_______________

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