Rab Xenon and Patagonia UL Down Hoody: Comparison and Long-Term Review

[Stephanie Jordan]

Companion forum thread to:

Rab Xenon and Patagonia UL Down Hoody: Comparison and Long-Term Review

[Jerry Adams]

Good article and comparison

good comparison between fleece, synthetic, and down

I like the burn holes : )

[Charles P]

Good review, thanks. I've been mulling over getting a mid-weight synth piece I can use year round and the Xenon might be the right piece.

[Sam Farrington]

Best article I've seen on the interplay of all the issues involved in choosing a light weight insulating top. And you actually sorted them all out well enough to not give me the usual headache. Great choice of garments to test. Thank you.

P.S. Think I still prefer a fleece top under a good WPB rain jacket for wet, chilly hiking, while saving the puffy top for camp and keeping it out of the rain. But you may be dealing with colder temps, and almost certainly you move faster and generate more water vapor.

[Serge Giachetti]

Nice comparison, Dave. I've used the xenon for nearly every outdoor outing I've been on for the last year and a half and have found it quite effective/versatile. The ability to dry out my base or shell layers beneath it has been its main asset over down. Cold/wet shouldn't happen often if you're layering/thermoregulating well, but when it does, its important to have a way to manage it. I know most people here poo-poo wearing puffies on the move, but I've found that if I'm cold and wet, I can dry out quite fast by moving quickly in this puffy. I take it off once I'm dry and feeling warm again. One trip I was especially glad to have the xenon:
I spent a long snowy day ice climbing in Rocky Mountain National Park last winter about 5 miles from the road. It snowed around 4-6 inches while we were out there, and my base/driclime was fairly wet by the end of the day. We made our way back primarily in the dark, bushwacking through thick sections of blowdown, with our tracks covered over and the temps hovering around single digits. I put the xenon over my base/driclime windshirt for most of the hike back. When we got back to the car I was amazed to discover that my base and dri-clime were bone dry with just a little bit of moisture still in the xenon. Had we lost our way on the return, I'm confident that my layers would have dried out enough that I could have thrown my belay jacket on top and been fine overnight. Since then, its provided me with some extra confidence and security in my layering system.

In winter, its a versatile enough to wear when belaying in mild temps (or restbreak), climbing or moving in frigid temps, or for transitions and descents bc skiing. For summer, it mainly gets used for stops/overnight, but its light and warm enough that I've never missed the WM flash i used to own. Speaking of which, I would add that the xenon feel significantly warmer than other light synthetics I've tried like the MB thermawrap parka. I'd attribute this partly to the primaloft 1, but mostly to the continuous insulation rather than stitch through. Its impressive that it feels about as warm as the pata down jacket, as I believe most synths in that weight class wouldn't. And finally, I'd agree that it has lost some insulation value over the time I've used it.

As to other options, I'm most definitely curious about water resistant down in the upcoming ghost whisperer and about polartec alpha garments. Seeing as I've torn this jacket about a 8 times, I don't think a down piece would be quite as functional for climbing/skiing (flying feathers), and the equivalent alpha pieces seem to be a bit heavier, I will likely stick to a xenon. Having powerstretch side vents and a more breathable shell material, like an arc atom lt, would make it even more versatile IMO.

Anyway, just thought I'd add my experience and pay tribute to a piece thats more than earned its place in my kit. Dave, hope to see you putting some of the newer insulations to the test going forward. (Sh**, I just used the phrase 'going forward'. Oh well.)

[David Chenault]

One of my speculative conclusions from this project, that isn't firm enough to include in the main article, is that the shell fabrics of both garments play a significant role in their warmth, especially the Xenon.

Jerry's article suggests that lower air permeability adds warmth, which is intuitively obvious but hard to quantify. With the Xenon you've got a very wind resistant fabric with an excellent DWR on both the outside and the inside; the shell and liner are the same fabric, so you're getting that insulative benefit twice over. My suspicion is that fleece sides (which I dislike) would knock the perceived warmth down quite a bit in demanding situations.

My overall conclusion here ties in well with those from my midlayer piece earlier this year. You want the whole system to be breathable so it will dry out via body heat, but to have a certain amount of delay to kill flash off. How much evaporative delay and where in the system it lives is a crucial personal decision.

[Ron Babington]

Any idea when the new model Xenon is slated to come out?

[Rick M]

del

[Ron Babington]

Thank you Rick.

[David Chenault]

Caveat emptor; I haven't seen the new Xenon.

I have a hard time believing the move to the new fabric has much to do with performance gains. The Quantum GL is plenty durable. What GL is not is pretty. As can sort of be seen in the article it's semi-transparent which lends it a technical, space-agey look. My most cynical analysis tells me that the new fabric is designed to give the Xenon more around town appeal (which is, after all, the backbone of the outdoor apparel industry).

Get the old Xenon while you can. I'm certainly considering buying one to have in reserve.

[Todd ~]

Altitude sickness can kill. The best treatment is to immediately descend. Please don't risk death due to High Altitude Cerebral Edema (HACE) just to finish a climb. If you get sick, go down. If you always get sick at altitude, talk to your physician about pretreatment options.

[Wim Depondt]

Something doesn't add up: this review states that both jackets provide comparable warmth. Über insulation expert Richard Nisley however concluded that all synthetic insulation – including Primaloft – have a lower clo than the official specs. The latter already give a much lower clo for Primaloft than quality down.

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=18950&startat=140

I have the impression that Richards test were conducted before first usage (read: before loss of loft due to (un)packing).

So, on paper, the down jacket should provide significantly more warmth than de primaloft one. The only plausible explanation I could think of is that the Xenon is a beter fit, thus trapping the heat better.

Wim

[Wim Depondt]

'pour la petite histoire': MILD altitude sickness (AMS) does not necesitate an immediate descent. One must of course not continue climbing. Mild altitude sickness:
– do not climb further – stay overnight
– take paracetamol (and if available: diamox, god I love that stuff)
– stay well hydrated
– when altitude sickness is gone next morning: continue climb. If not descent.

But yes, altitude sickness can kill if one does not monitor the symptoms

[Jerry Adams]

When they climb Everest, they hike up to higher altitude, then go down a few thousand feet and stay overnight.

[michael willkie]

I found the same thing while wearing merino wool and the Xenon while walking. Before I would have worn a softshell or a hardshell, now I just change the bottom tightness and the zip,and the hood. Not sure if I find a heat balance or if the Xenon is a good breather, but I seem to find
my wool comes out pretty dry. I like the Xenon alot , and the wind doesnt seem to matter.

[James holden]

ive said it over and over again … the main advantage of a synth is that you can dry out other layers underneath it …

ive been recommending a combination of down underlayer+synth overlayer forever for both sleeping and jackets

ex. MB exlight + dead bird atom … or down bag under synth bag/quilt

add a hawt nalgene to the mix in camp or some not too strenuous activity and you can dry off thin layers (even down!!!) even when theres no sun

the key is that body (and other) heat will generally push out moisture to the outer layer …

as to down and synth being more or less "equivalent" in terms of "warmth" … this can EASILY happen in the right (or wrong) conditions … right now with PL1, many consider it to be the equivalent of 500-600 fill down … remember that these fancy 900+ fill down jackets are measure in MINIMAL HUMIDITY … in real life humidity they easily drop to the 700 fill range … and in wet damp PNW conditions, probably even less

;)

[Ethan A.]

For those of you that wear the Xenon, do you have it sized to wear under your shell, or over it as a rest-stop and camp layer?

[Ethan A.]

I like the idea of a lighter puffy + heavier puffy insulation jacket instead of a single heavy one. Dane at Coldthistle recommends the Arcteryx Atom LT as an inner layer, and the Atom SV sized a bit larger to wear over it. I think he only goes with synthetic. Keep in mind his use is climbing specific – for backpacking and hiking, another jacket like the Xenon might be a bit warmer because of the fit (tighter hood) and lack of breathable stretch fleece side panels that are on the Atom LT.

For a sleep system, down under synthetic makes sense for the weight savings, and you are much less likely to get your down bag wet with proper care than a jacket.

[David Chenault]

Will, I didn't see your comment until now. Allow me to highlight a few things from the article by way of answering it.

Lab measurements of clo in insulating garments do not always agree. Richard's work is important because of how well its been disseminated, but suffers from small sample sizes. As noted in the chart, there is substantial variation in the numbers I was able to find for the Xenon and UL Down Hoody. If you take the far ranges, the later is over twice as warm as the former. If you take the near ranges, they're equivalent. This nicely covers the range of anecdotal/subjective reports.

My own measurements suggest, as noted, that Primaloft does indeed loose a lot of insulating value in the course of normal use. My methods were not rigorous enough, even as a single subject design, to merit reproducing in any greater detail. Users take this for what it is worth.

Most significantly, it bears repeating that differences of less than .5 clo are held as being not reliably discernable by human subjects. When talking about relatively light insulating garments like these, it is worth keeping in mind that variations in individual perception, combined with the aformentioned variations in reported clo, makes quibbling about small differences not especially meaningful. Things like fit and DWR quality are far more likely to matter for the end user.

[James holden]

I like the idea of a lighter puffy + heavier puffy insulation jacket instead of a single heavy one. Dane at Coldthistle recommends the Arcteryx Atom LT as an inner layer, and the Atom SV sized a bit larger to wear over it. I think he only goes with synthetic. Keep in mind his use is climbing specific – for backpacking and hiking, another jacket like the Xenon might be a bit warmer because of the fit (tighter hood) and lack of breathable stretch fleece side panels that are on the Atom LT.

synthetic under synthetic works fine, but at some point it gets rather heavy … the advantage being that you can take off a layer for slower stop and got activities, like climbing, simply by peeling off a layer without taking everything on and off …

for what people do here, IMO down under synthetic makes more sense … generally you are hiking … or your stopped and in camp

not to mention down is generally lighter (MB ex light) … and a thin down sweater you can dry off under a synth puffy

;)

[Stephen M]

EJ,

I think Dane is using Down again since he discovered the Montbell Mirage. I have both the Atom Sv and Xenon which I pair up with down.

I team up the Xenon with a Stoic Hadron hoody (total weight 600g) which works to about 25f, Atom Sv and the Hadron (800g) down to 15f and Sv with Gooses Feet Parka down to -15f (1kg)

[Oliver Nissen]

I somehow missed this stimulating article during a busy May.

Although the fact that this is a comparison between apples and oranges has been acknowledged, some aspects of the differences haven't been highlighted (or have been underplayed when representing the results.)

Quilting – may reduce flappage and windage.
Insulation with quilting through multiple layers is stiffer, resisting flapping that increases convective heat transfer and pumps air in and out of the garment. Winds where this issue would pose a serious problem may not have been felt by Dave during his testing.

Flatter lying surfaces – greater contact area with surface of garments beneath.
In the case of a wet t-shirt drying out under these two garments, I wouldn't be surprised if this was the main factor in the Xenon out-performing the UL Down Hoody.

(At a microscopic level these highly calendered, slick low-denier fabrics have a lower angle of contact with water than their lumpier surfaced, higher-denier but same-substrate brethren – the mere fact of a bumpier surface actually repels water droplets – that's how the lotus leaf effect works.)

The intricacies of the fabrics – hygroscopicity and air permeability.
The fabrics here superficially look to be very similar, but I've recently seen a study where a range of Nylon 6s were compared and their moisture regain varied from a fraction above 1% to a fraction under 10%. Add in a potentially greater variation in air permeability between the fabrics, and insulation aside, the variation in dry times for garments consisting of twin layers of these fabrics may conceivably vary enormously.

(Same branded membrane, but with a different face-fabric and you can see maybe about a 60% difference in breathability scores in RET and cup tests. There's huge variation and people just wrongly assume there isn't.)

And all of this is before we're really making a like-for-like comparison between the insulations; e.g. conductive heat transfer under compression, compressibility (in the wet, the dry, oil-soiled…) etc. That's another long list for another time.

Food for thought…

[Sean Passanisi]

Nice article.

FYI, Patagonia reports using 98 Grams (3.46 ounces) of down fill in the UL hoody.

[David Chenault]

Sean, they were claiming 2 oz in the 2012 version.

Oliver, thanks for the comments. While there may be differences between Quantum GL and Patagonia's proprietary fabric, I am highly skeptical that they're significant enough to make a difference noticeable across users. Ditto on the effects of quilted down v. non quilted synthetic in a coat of modest thickness. We outdoor geeks like to think these minutia (and others, discussed above) matter in the field, but they simply do not 99% of the time.

I should also note that the Patagonia continues to impress in how well it retains loft under daily use. The Xenon, on the other hand, it ever flatter in terms of warmth. When comparing it to a Climashield quilt (which had comparably heavy use over a longer period of time) I just decommissioned, it's hard not to be a Primaloft skeptic when it comes to loft/warmth retention.

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