A New Paradigm for Understanding Garment Warmth

[Richard Nisley]

Pat,

They test the same. The key to maximizing the warmth of small down channel garmets, like these, is to always wear them under a windshirt or hardshell. This will capture still air pockets over the seams for significant additional warmth.

[Patrick Young]

Richard
Do you have the clo for the Patagonia ultralight down shirt? I want to layer it with the ultralight down hoody for colder temps.
At what temp would that combo be thermal neutral?
Thanks
Pat

[Richard Nisley]

Patrick,

The Patagonia UL down shirt is 1.66 Iclo. That shirt plus a MB UL Down Hoody and doing camp chores, sheltered from the wind, will be thermo-neutral at ~31F.

[Ismail Faruqi]

Hi Richard,

Could you tell me the lcl clo of following combination:

Top:
1) 100% merino 150gsm
2) Capilene 4 half-zip
3) Rab Alpine Pull-on
4) R3 hi-loft
5) Crux Lava (310grams of down)

Bottom:
1) R1 thights
2) Softshell Pant
3) Feathered Friend -40 pants

What is my thermo-neutral point when belaying and doing camp chores? Thanks!

[Patrick Young]

Richard,

Do you have a clo on the Golite Bitterroot?
Thanks

Pat

[Richard Nisley]

3.44

[Erik H]

I have an old wild things sweater that I want to replace, that has the 2 layers of 60g primaloft 1 quilted together, and the chart gives it a 1.46 iclo. The Rab Xenon, with one layer of 60g primaloft has an iclo of 1.51, and the Rab generator, with 100g of primaloft 1 has an iclo of 2.27. Shouldnt the wild things be similar to the generator, or higher? Thanks

[Richard Nisley]

Erik,

I have made multiple prior posts explaining that NO synthetic garments that I lab tested, unlike the down garments, were close to their theoretical Iclo specification. I don’t doubt the value of the synthetic insulation’s specified Iclo at the time of manufacture, BUT after being manufactured into a garment and boxed and unboxed during distribution, they test, on average, 51% of their theoretical values. This chart is a portion of one of my many prior posts on this topic from a couple of years ago:

About the same time that I did these tests, BPL was manufacturing synthetic garments for UL backpacking. They were also recommending that synthetic garments and quilts be used during their courses. So, TO BE POLICTIALLY CORRECT, after first posting multiple times that ALL synthetic garments that I tested averaged about ½ of their theoretical Iclo value, I posted all subsequent synthetic garment’s Iclo values based on their theoretical specs. For my personal sustained-wet-weather use, I select garments based on the -51% of Iclo spec. lab test results. I try to not dissuade others from making their decisions based on the manufacturer’s specifications if they choose to do so.

[Brett Peugh]

I wonder if the Fugu is still king of the hill?

I am still trying to figure out how it is that much warmer than my Montbell Alpine jacket. The Fugu is a sewn through construction with less loft and down while the Alpine is box baffled and very puffy. Is it just the metalized inner? Where can I get a jacket just made out of that stuff?

[. .]

@ Brett – the Fugu has a reflective barrier (think NeoAir with down fill) and an Epic-like fabric which both aid in mitigation of heat loss via radiation and convection respectively. I know of no other down garment that compares. Especially when combined with a well-designed down hood, I still consider it king of lightweight the down-heap. It is hands down the warmest jacket that I own and I only bring it out for sustained winter weather conditions.

See this thread also: wee bpl thread link with opinions, photos + specs of Fugu

[Brett Peugh]

Yeah, I just wish my XLT was bigger to fit better.

[Christoph Blank]

Dear Richard Nisley,

I'm looking for synthetic insulation and came across primaloft vs the new polartec alpha.
I wondered how vests and jackets compare, for example:

Rab Xenon X
http://rab.uk.com/products/mens-clothing/synthetic-fill/xenon/xenon-x-vest.html

Rab Strata Vest
http://rab.uk.com/products/mens-clothing/synthetic-fill/polartec-alpha/strata-vest.html

(or the primaloft atom vest by arcteryx)
I assume that since alpha is more breathable, one needs more insulation (that might explain the additional weight of the rab strata vs the xenon).

Could you enlighten us a bit please?

[Woubeir (from Europe)]

The Xenon X uses Pertex Quantum at 36 g/m².
The Strata uses Pertex Microlight at 49 g/m².

The Xenon X has 60 g/m² Primaloft One/Gold.
The Strata has 80 g/m² Alpha (the only available weight at launch).

P1/Gold is, according to my calculations, 2,5 x as warm as Alpha. Plus the fabrics used for Strata are, hopefully, a lot more air-permeable than those used for the Xenon X.

[Edward John M]

I may have missed something in the last 150 posts but I saw nothing on the insulating value of pants. I find that LW insulating pants have such a great bearing on cool weather comfort that I would never not take them once the temperature dropped below 15C

I have a pair of UL insulated pants from OR with 60GSM polyester which are borderline and a pair of Patagonia MARS pants which are just about perfect and I think these use 85GSM polyester batting.

I have other HW insulated pants to in my M-65 ECWS pants liners which fall in between.and the Happy Pants which are far too heavy and warm for Australia but may come in handy in the Arctic/Antarctic

 

[Brad Rogers]

15*C is 59*F right?  I generally don’t even take an insulated shell at those temperatures.

[Edward John M]

Yep Right on the edge of hypothermia country.

Sorry that would be 15C maximums, winter minimums can be 20 degrees lower at nite in the hills and 10 to 12C lower at nite everywhere else

I add in the OR pants because they are lighter than my Goretex storm pants or the Polartec and I can use them to sleep in if I bring a LW bag

[Edward John M]

@Brad

You may not be familiar with our conditions Brad, like Scotland. I just looked at the information for the area where I ski, Falls Creekin Victoria

-1C Dew point -1.6C humidity 99%

Our soggy conditions mean we really do need to wear much more clothing.

 

 

[Edward John M]

Just bringing this back to the top to clarify something. I’m just wondering where on the scale my older Patagonia DAS is?

If it has lost a third of its new loft that says to me it as as warm as the Puffball / Micropuff when new but it feels much warmer than that. I can’t even remember now what polyester fill the garment uses but generically aren’t all DAS parkas supposed to have equivalent performance in use?

[Richard Nisley]

Edward,

I have test information for a couple of the older DAS models:

2009 3.34 Iclo 21F Thermo Neutral for Camp Chores (TN)

2013 2.76 Iclo 27F TN

As is the case for all synthetics, they degrade rapidly. As a general rule, I would guess 30-40% less Iclo after 2 years of use.

[Edward John M]

Not sure I understand that Richard, the unit with the higher Clo value has a higher TN point?

It has lost loft, perhaps as much as 30%but subjectively it doesn’t feel as if it has lost 30% of its warmth and is warmer than the combination of two layered nano-puffs [ XL pullover + XXL Nano-bivvy] so much so that I just sold off the Nanopuff pullover.

Substituted with a P Micropuff vest purchased thru here

Was there a post somewhere that mentioned loss of loft did not automatically mean loss of warmth due to the increased density of the fill making a difference?

Have you had a chance to test the new Patagonia HyperDAS yet?

[Richard Nisley]

Iclo typo corrected.

Unlike down, synthetic insulations are manufactured at their optimal density for clo/oz. As their density increases from use or compression, the Iclo will go down. How much?…  requires a lab test which is impractical on an old jacket.

Patagonia HyperDAS – Vendor says ~ = 2.4x insulation of Nano Puff Hoody = 144 g/m2 of Primaloft Gold + more dead air space from insulation folds = approx the same insulation value as the 2009 DAS version with 158.9 g/m2 of Primaloft Gold.

[Edward John M]

Thank-You

~3Clo when new sounds right; it is about that old. I just purchased S/H but from somebody I trust, was purchased to use [ briefly] in Antarctica but stored and unused since then. So I am going to assume ~2Clo then and plan accordingly

Thanks again

[Edward John M]

I checked with Patagonia customer service, it is older than I thought.

2002 – 2004 Polargard 3-D 4 ounce in the sleeves and hood and 5.6 ounce in the torso but it was cool here last week and I wore it over a cotton T-shirt in a stiff breeze, far too warm at 11C and walking slowly.

Richard is the comfort effect of wearing more than one windproof layer measurable ? I have found that around -8C and lower that I feel much warmer if I wear a windproof over my base layer and when I stop I put on a fleece and a secondary windproof This was before I saved up and bought my first Nanopuff, was I getting an additional 7mm of free insulation or was I feeling something else?

[Richard Nisley]

Edward,

If static, the benefit is as you stated.

The adverse affect, when active, is the “Combined CFM Regression” found on page 21.

[Opogobalus]

I may have missed something in the last 150 posts but I saw nothing on the insulating value of pants. I find that LW insulating pants have such a great bearing on cool weather comfort that I would never not take them once the temperature dropped below 15C

This is an interesting point to me. I noticed the EE 2.0 Apex pants weigh only half an ounce more than my poly thermal leggings I bring on nearly every trip (and only put on once stopped). While they’re sufficient most of the time, there are chillier times and the apex pants would be a lot warmer for the weight.. but would wearing them directly against the skin while stopped/sleeping be a bad idea?

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