Vest vs Jacket

I agree with you Josh, vest is good down to even a little into the 20s.

I sometimes go down to 20 with a vest, but that's probably pushing it. And maybe it will be 20 on one night when I get up, so I'll stay in my sleeping bag a bit longer and wait for it to start warming up.

I see people wearing parkas and jackets, not vests, here in a Fairbanks winter. The Inuit have always worn parkas. Those Denali and Everest photos don't show people wearing super puffy vests.

I will agree with Josh, Jerry, and Buck. As well, Dale W.'s first paragraph pretty much sums my experience. I understand the points made about super puffy bays and core temperature in extremis and will just accept they are true.

I like vests and will wear them with other layers on the arms and be happy. I am not happy with very little or nothing on my arms. If it is chilly and i have on a vest with windbreaker and t-shirt, i am more happy to add a bit to my arms rather than add more to my torso…

I think it might be worth considering variable weights between arms and torso. You want the warmest thing for the weight.. The warmest (balanced with most comfortable) might be, say, 2.5 oz/yd in the arms and 6 oz/yd in the torso. I realize you want down but weights of synthetic materials is the easiest way to make the point… I just grabbed the weights of the top of my head but they also illustrate the point.

Now.. What the balance of fill distribution should be.. Who knows? See several manufacturers use variable fill and advertise the weight of synthetic fill. This might help you to determine a ratio of torso to arm fill. You might want to cheat a bit more to the torso as i do think more to the torso versus the arms is better and the manufacturers might be a little conservative in that they realize people might not buy a jacket that seems to have very lightly insulated arms…?

I just don't think a super thick vest only is best.. If it were, why waste all the sleeping bag fill on your legs? If super puffy torso is the complete answer, take the fill in the legs and put it in your torso.. :)

PS – I didn't realize this was such an old thread! The more recent comments do seem to be in favor of the jacket. Reading the thread, i remember thinking the comments on page two were more in line with what i would recommend. Those are the new comments. Interesting the different feel in the responses between November 09 and now… Or, maybe, it is my imagination. :)

It is obviously a balance that you're after :) Yes, with equal insulation round them, you lose more heat through the core than arms etc. Equally obviously that ratio reverses if you massively insulate your core and not anything else. (Legs of course at some point too.).

The vests win when you're only trying to add a relatively moderate amount of overall insulation. So either just not much needed overall or something like a synethetic jacket/down vest combination. Or even down/down I suppose but I'd not be surprised if people didn't already under insulate the arms in down jackets.

Multiple garments will naturally have an attached weight disadvantage, almost certainly outweighing the vest/jacket thing. Nicely flexible for some cases though.

I put a lot of credence into Richard Nisley’s posts/information. There’s been a lot of talk here recently about the weight of the new Montbell Plasma Parka and its respective iclo value. However, I have just received shipment of a Nunatak vest with approximately the same amount of down as the Montbell Plasma Parka (albeit 900 fill, not 1000). On paper, I should be able to maintain my core warmth better with my hooded Nunatak vest than with the Montbell Parka. The finished weight are very close to the same, too, and I didn’t have to resort to a 7 denier shell. I opted for the .8osy Pertex which is a mild improvement at 10 denier, as I understand.

I bought the vest to support Southern Appalachian shoulder season ultralight trips where I wanted to use my 14oz Arc Ghost quilt. I could leverage this hooded vest to assure comfort to around 30F in a pinch and have adequate coverage around camp. I would have a proper WPB rain shell to support this system. I also have the kangaroo front pocket included (in the weight).

I have another vest related post regarding the new Patagonia Nano Air Light Hybrid but I will start a separate thread about it.

I’m a scientist..I’m Smart..You want warmth get a Jacket..Now forget the Part that I’m a Scientist and I’m Smart cause I lied.But just get a Jacket..MH Ghost Whisper 7oz jacket, wear a merino top and If you get hot take off the Jacket..

Jacket – in camp with little activity. selected based on weather outlook, this is my main outerwear.

Vest – when a little insulation is needed while active or as backup to extend the comfort range of my main outerwear.

If I’m choosing only one, it would be the jacket.

If the garment has uniform fill, the core insulation provided is proportional to the relative body surface area (BSA)  covered. Hoody = 52%, jacket = 48%, hooded vest = 40%, and vest = 36%. So, a hooded vest will be perceived as 77% as effective as a hoody with the same iclo or clo.

Uh… I cannot believe we are debating this.   We will take a winter trip for 5-days and I’ll give you the vest and I’ll take the jacket with hood.

Ok, so if I do some math here, the iclo/clo of the Montbell Plasma Parka may be less due to the distribution of the down throughout the jacket but will offer ~23% better effectiveness. The Nunatak Hooded Vest, on the other hand, may offer a higher iclo/clo due to the concentration of the down around the core area (particularly when coupled with a WPB/Wind jacket, which I always carry). So the 23% gain of the Parka may be offset by the higher insulative value of the Hooded Vest. Again, both the finished weights and fill used appear to reasonably close.

Nunatak Hooded Vest size Large: 136g of fill and 256g total weight per the invoice. I actually measured 9.1oz *with* the stuff sack on my digital work scale last night.

Montbell Plasma Parka (presumably size Medium?) 96g Fill and 237g total claimed weight per the website.

@kevperro Hence my usage of the above phrase “on paper.” Also, since we’ll both carry a WPB jacket then I may have the better overall clo/weight carried. Finally, for a winter trip I’d just take my Skaha Plus sweater with hood.

@Robert  –  You could do a calculation of a body map using an infrared scan showing surface temps and the delta T across the jacket and calculate joules of energy lost per surface area – per unit time.   It would give you a nice neat total calculation of total lost energy from the system.

Of course, you will find a calculation doesn’t necessarily translate to comfort.  Neglecting your extremities may help in the joules of energy lost calculation but it doesn’t help in the comfort category. You could make the argument that it would translate to survivability but I’d argue even that isn’t necessarily true.    Any calculation you perform would have to take into account the fact that if you ignore extremities it is less comfortable than if you keep your overall body in a reasonable range.    What is most important to survivability is a balance of your psychological AND your physical state.     Anyone who has suffered for a significant amount of time in the outdoors can attest to the wear and tear it does on your psychological state of mind.

But this is all academic.    Trading off pack weight for an ounce or two of goose down is a foolish choice in when the weather is cold.

@kevperro I appreciate the reply. I agree about the value of having both physical and psychological bases covered. Risk assessment is another very fair point. What I’m most interested in figuring out what the “MPG” is for each garment. If my calculations have merit then my Nunatak piece should carry me further for the same weight, which makes me even more happy with the purchase. Either way I still have my hooded Skaha with sleeves for trips where freezing temperatures are *assured.

yeah, calculate Joules lost

your arms have a little lower surface temperature, so there’s a little less heat lost.  Insulation around your torso will save a few Joules.  Fairly minor though.

another thing is the cross section of your arm is smaller so insulation is less effective.

say, your arm cross section has a radius of 2 inches.  cross section area is pi * r^2 = 12.5 in2

add 1 inch of radius to include 1 inch of insulation = 28.3

the area of the insulation, the ring between your arm and the outside of the insulation is 15.7

the circumference of your arm is 2 * pi * r =  12.5

the ratio is 15.7 / 12.5 = 1.25 – this is the effectiveness of insulation on your arm

do the same for your torso – say it’s a 6 inch radius – then the effectiveness of insulation is 1.08

insulation is 1.25/1.08 = 15 % more effective on your torso

you really need a spreadsheet to calculate it all, it’s a bit complicated

It comes down to a few ounces difference. So a jacket. The question is sort of academic. In the real world, you want a sufficiently warm garment. Get a more robust jacket and leave a layer at home to compensate for the extra few ounces of down. Or go hiking with one half less power bar and call it even that way.

I agree it doesn’t make much difference

I like my arms free rather than constricted by a jacket

Wear a vest with a little more insulation and you’ll be as warm for a little less weight

If your torso is warmer because of the extra insulation, there’ll be a little more blood available to send to your arms

@retiredjerry thanks for jogging my memory although admittedly my brain hurts a bit. My high school physics teacher was the first to introduce me to backpacking on the AT.

@book my trail name in ’96 was the Professor so that should help explain matters.