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RatherBOutdoors Member
Joined: 17 Jun 2017 Posts: 50 | TRs | Pics
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So, we have temperature ratings for sleeping bags, etc. Why don't we have any kind of (generally used) scale for comparing clothing?
Even if we didn't have a specific temperature rating, at least a comparative rating would be useful.
I expect someone has done something along these lines, but here's a (maybe silly) thought experiment of one way to go about this:
- fill a water bladder with warm water at, say, 98.6 degrees
- wrap it in the clothing item to be tested
- place it in a chilled room (refrigerator?) at, for example, 35 degrees
- measure how long it takes for the water to reach the ambient temperature
I'm sure this is a non-trivial test, but would it give us a basis for a meaningful comparison?
Is there some other test that can be done or is being done that could give one an idea of how warm one coat me be compared to another?
I'd like to hear your thoughts.
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Riverside Laker Member
Joined: 12 Jan 2004 Posts: 2818 | TRs | Pics
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It might be better to measure the time to drop, say, 20-ish degrees (down to 78F). Getting to 35F can take a long time, and isn't as significant to how your body would feel. But the lower the delta temperature, the more error in the measurement, so maybe going even lower is worth it, maybe dropping 38 down to 60F?
You might want to hang the bladder and clothing, so whatever you lay it on isn't a factor. But that's hard in a refrigerator.
But it's a neat idea.
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Cyclopath Faster than light
Joined: 20 Mar 2012 Posts: 7697 | TRs | Pics Location: Seattle |
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Cyclopath
Faster than light
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Sun Jan 23, 2022 10:43 am
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RatherBOutdoors wrote: | So, we have temperature ratings for sleeping bags, etc. Why don't we have any kind of (generally used) scale for comparing clothing? |
A fleece might keep me warm sitting around telling jokes at 50F but I can ski in it at 30F because I'm generating warmth by moving. A sleeping bag is different than clothes because you use it when you're completely sedentary, normally inside a tent that blocks wind for you. Most of the variables that make it impossible to give clothes a rating don't exist for sleeping bags.
You're right that comparisons are useful.
For down specifically, you can get a rough idea by multiplying the fill power and the fill weight.
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Randito Snarky Member
Joined: 27 Jul 2008 Posts: 9495 | TRs | Pics Location: Bellevue at the moment. |
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Randito
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Sun Jan 23, 2022 10:56 am
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There is a temperature rating system for sleeping bags because the US military developed the standard as part of their specification process for procurement.
Temperature ratings for sleeping bags are relatively simple as the metabolic rate of a sleeping person is relatively easy to calculate.
Thermal output of person on the move is highly variable depending on the individual and on the activity so any sort of temperature rating for clothing is problematic.
A more useful measure might be akin to the R-Factor used for insulation used for building materials. These are based on the thickness of the insulation and a measure of the inherent heat resistance of the material.
Some outdoor products , namely sleeping pads use R-Factor as part of their advertising.
In the clothing realm the marketing departments seem more concerned about being on trend with colors than they are about providing technical measures of their products. On thing they do tend to specify is some sort of waterproofness and breathability measures that are highly suspect.
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RatherBOutdoors Member
Joined: 17 Jun 2017 Posts: 50 | TRs | Pics
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I wouldn't expect an absolute temperature rating, analogous to sleeping bags, for the reasons folks have mentioned. Still I think a relative rating (yes, like the R-rating) would be useful as a reference point so that I could know, for example, Jacket A was warm enough for hiking in X conditions so if I buy Jacket B, with a similar rating, I have a reasonable chance of staying comfortable.
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Randito Snarky Member
Joined: 27 Jul 2008 Posts: 9495 | TRs | Pics Location: Bellevue at the moment. |
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Randito
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Sun Jan 23, 2022 12:11 pm
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I don't think the manufacturers are interested in publishing any sort of measurable data. Only if there were agreed upon industry standards across brands would it be possible to have what you are seeking.
I think there are a lot of interests in the industry that would work against any such standards. One example is "Thinsulate" brand insulation, which claims "warmth without the bulk" and I recently saw a FB for some clothing claiming "twice as warm, half the bulk".
Obviously the marketing departments for those brands don't want any sort measurable standards for insulation performance.
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RatherBOutdoors Member
Joined: 17 Jun 2017 Posts: 50 | TRs | Pics
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Maybe one or more of the "independent" gear reviewers would be interested in reporting this kind of information...
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thunderhead Member
Joined: 14 Oct 2015 Posts: 1511 | TRs | Pics
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It would be great to have such data for our layers and combos of layers and conditions.
Id think the best set up would be some sort of ballistic gel torso with arms(because various layers arent necessarily uniformly constructed across sleeves/shoulders). Place a number of thermometers in each. If you had access to both a sauna and a walk in fridge that would be great. Warm them up in the sauna until stable at ~99F(about a day?). Place in walk in fridge. Turn on(or not) fans or misters to simulate various combos of wind/no wind and moisture/dry conditions. Measure time to drop to say 80F.
Rinse and repeat. Sounds like a pretty in depth process to build up a good robust dataset. Lots of combos potentially.
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Cyclopath Faster than light
Joined: 20 Mar 2012 Posts: 7697 | TRs | Pics Location: Seattle |
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Cyclopath
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Mon Jan 24, 2022 5:36 pm
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Keep in mind there are different ways of getting cold. This sounds like a good way to measure how clothes protect you from heat leaving your body to equalize with the ambient temp of the air around you. Wind is a different thing, that's why the wind cuts through a warm fleece like a hot knife through butter. If you wear too much while you're active you'll sweat and then the water on your skin and in your clothes pulls the water out of you in a way that doesn't happen when you're dry. I tend to be more comfortable overall in a grid fleece that's a bit less warm but breathes better, keeping me from overheating and getting all sweaty.
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