Pullover insulation comparisons: delta vs XP vs PL Sport
Posted: 26 June 2007 01:44 PM   [ Ignore ]  
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Insulation comparison:
BMW cocoon: 2.0 oz basis weight PG delta * 0.67 clo/oz = 1.3 total clo. 
Joe’s Kinsman: 3.0 oz basis weight PL Sport * 0.74 clo/oz = 2.2 total clo .  As size large patterns use @ 2 sq yds material, this would add up to about two ounces more weight in equivalently made jackets from 3.0 oz sport and 2.0 oz delta.
(2.2 - 1.3)/1.3 * 100%=  69% more clo in your 3.0 oz PL Sport Kinsman than the Cocoon.

other configurations of the Kinsman:
1.8 oz PL Sport * 0.74 clo/oz = 1.3 total clo.  Equivalent clo, lower basis weight insulation.  As size large patterns use @ 2 sq yds material, this would add up to about a half ounce less weight in an equivalent jacket for 1.8 oz sport as compared to 2.0 oz delta.  It’s also important to note that small basis weights of Primaloft are extremely consistent, but small basis weights of continuous filament insulations like 2.0 oz are less consistent (“waves” of high&low; points). 
Delta fans sometimes claim that fiber size leads to quicker drying as a reason why delta is good, even though it isn’t as warm as PL, but omit the fact that Primaloft fibers are siliconized and as such do not absorb as much water in the first place. 
the bottom line: A 1 to 1 substitution of 1.8 oz PL Sport for delta would give you a jacket just as warm at a lower weight than 2.0 oz delta.

2.5 oz XP * 0.82 clo/oz = 2.1 total clo
(2.1 - 1.3)/1.3 * 100% = 61% more clo in the 2.5 oz XP Kinsman vs 2.0 oz delta.  In a size L, this would be roughly 1 oz more weight for the 2.5 oz XP vs delta in equivalently made pullovers for 61% more clo for the XP pullover.

Continuous filament insulations Delta and 3D were always a tough sell for me in apparel.  On just a clo-clo basis, 3D (clo .63) and delta (clo .67) are less than PL Sport (clo = 0.74) and PL 1: (clo = 0.84).  Add to that the facts that the fibers are non-siliconized and absorb more water than the siliconized fibers of Primaloft, that they’re stiff feeling, and that their main strength of being able to span large panels with less quilting is not as significant with the smaller apparel panels, and there’s not a whole lot of reasons to choose a continuous filament insulation in apparel.

The newer continuous filament insulations like XP and its Berry compliant version Combat have higher clo values (0.82 and 0.78 respectively) and are a little bit softer feeling, but even so in apparel it’s hard to get me to switch away from Primaloft.
In anything with large panels, such as a sleeping bag or quilt, continuous filament insulation is at its best. For me this would hold true even for the older less efficient continuous fiber insulations like 3D over Primaloft.  It’s just that much better that the new breed of continuous filament insulations like XP and Combat are much more efficient than the older ones: 3D (0.63 clo/oz) and Delta (0.67 clo/oz) while retaining the same strength-over-large spans characteristics that make them so desirable in large panel items.

AYCE

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Posted: 30 June 2007 01:58 AM   [ Ignore ]   [ # 1 ]  
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For folks interested, here’s some summary graphics of the independent tests conducted by the Hohenstein Institute that compare the clo values and water absorption of various continuous filament and short staple insulations.  Based on the displayed clo value of 0.67, the most likely candidate for the continuous filament insulation is Polarguard Delta.


AYCE

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