Down vs. Primaloft

[Soda67]

Wow! So a 3.5" thick solid synthetic quilt for a 0* rating? That's crazy. Yep, Down 1, Primaloft 0

By the way Boston, I finished my quilt, and it turned out great! Thanks for the input on it, and especially the modified calc. Take a look at my thread "underquilt completed and successfully hung at 9200 feet" for pics.

[BillyBob58]

Primaloft will weigh more and be less compressible vs the same temp rating in down.

Generally speaking, from a loft standpoint, down and modern synthetics will give the same temp rating at the same loft. So the only difference is the weight of the material required to achieve that loft. Down will always win.

Wow! So a 3.5" thick solid synthetic quilt for a 0* rating? That's crazy. Yep, Down 1, Primaloft 0

I know they are supposed to be the same, that is what I was always told, but I am not sure loft/warmth is the same with synthetics vs down. For 1 quick if extreme example, how warm is a 1" thick high quality CCF pad, even when we are laying on them and possibly compressing them a smidgen? Maybe about 20F? So regardless of fill power how warm would a 1" loft UQ be? No where near 20F.

So OK, a solid piece of CCF might be too different to fairly compare. But how about a torso size down UQ with either 0.6" loft or with a total down fill of 2.5 oz, what would be the estimated warmth of that?

I have- wearing only cotton tee shirt and jeans- been warm somewhere into the 40s with a old style WB Yeti UQ that had one layer of 2.5 oz/sq./yd Climashield XP in it(CS Apex is supposed to be a bit warmer). Since the layer under me was appx. 1 sq.yd, that means the weight of insulation was about 2.5 oz. And it's thickness was 0.6" fully lofted. So warm for me somewhere in the 40s, wearing cotton, with a mere 0.6" loft. I have heard from a few other folks who had similar experience with CS UQs. ( Although I sometimes think the CS TQs may not be quite as warm at a given thickness as they might not drape down on me as well as down)
http://www.thru-hiker.com/x/index.ph...viewthread/25/

[Boston]

When talking synthetics I'm talking polyester fill insulation like climashield or primaloft. I'm not comparing CCF. I'm not sure what temp rating 1" of ccf would be.

YMMV, everyone sleeps different. A lot of people say a 2 layer pluq gets them to 40. It only goes to maybe 55 for me. My statement is based on converting down loft to CLO based on accepted loft/warmth values, and EN rating of 6 CLO at 32*F needed for comfort, then comparing to published CLO and loft values for Climashield Apex. What I found was at equal CLO, loft was the about the same.

[BillyBob58]

When talking synthetics I'm talking polyester fill insulation like climashield or primaloft. I'm not comparing CCF. I'm not sure what temp rating 1" of ccf would be.

YMMV, everyone sleeps different. A lot of people say a 2 layer pluq gets them to 40. It only goes to maybe 55 for me. My statement is based on converting down loft to CLO based on accepted loft/warmth values, and EN rating of 6 CLO at 32*F needed for comfort, then comparing to published CLO and loft values for Climashield Apex. What I found was at equal CLO, loft was the about the same.

OK, I realized you were not asking about CCF, and I certainly wasn't suggesting you consider it. I just threw that in to show the extremes you can have in differences between a synthetic insulator and down. Sorry for the aside, but then I quickly got back to CS vs down.

I can not speak to the EN rating system, I just don't have much experience with it. I don't know how they decide on a rating that would apply to most folks in the real world, though I'm sure they have a valid scientific method. And admittedly my own experience with one layer of 2.5 oz/sq/yd and 0.6" loft CS is and individual result, and people vary greatly, even if some other folks have had a similar result that is not exactly scientific.

However, there are many people here at HF who have confirmed that the AHE CS UQs like the Jarbidge are rated pretty conservatively. While there are probably some who would find the ratings right on or not quite right on, there have been quite a few who have found they can go a good bit lower than what these UQs are rated for. Maybe even the majority of users have had this result.

So, AHE uses a 6 oz layer of CS Apex in the 25F rated Jarbidge. I don't know the loft, but I do know 5 oz/sq/yd CS is rated at 1.2" loft. So I am guessing the loft must be in the ball park of 1.4" for a 6 oz/sq/yd layer of CS Apex.

The very same company also makes the 3/4 length Flamethrower down UQs, stuffed with 9 oz of 800 FP down. This quilt is rated thus : " This quilt is taking most users easily to 30 degrees and some even lower..So far we have heard of one user hitting 19 and they said they were toasty.......The quilt lofts to at least 3 inches of down bulging outward from the 2 inch tall baffles".

So according to the manufacturer, they have a CS Jarbidge rated at about 25F, which many here have taken lower, and it probably(by my rough guess) has about 1.4" average loft.
They make an 800 FP UQ rated at 30F though at least one has taken it to 19F. It has 2" baffles with a peak loft of at least 3".

So with the same manufacturer an approximately same temp rating, but one has approximately double the loft. Assuming the manufacturer knows the actual comparative warmth of the quilts he sells, and if warmth is the same if loft/thickness is the same, how can this be? This also confirms my own experience when I use both my down UQs and PeaPod and my CS Yeti UQ. My down gear is very warm for the weight, though I really can't say it is all that much warmer- if any- than CS Apex for the weight, at least for 45-50 rated UQs. But it certainly packs down a good bit smaller, down wins that easily.

But when it comes to thickness/loft, I can not imagine being warm in the 40s, even the high 40s, in a torso length down UQ with only .6" loft. Maybe 1 or 1.5", but not .6". (in fact, I know of one family of summer weight down quilts, rated 40-45F, which have 1.5" loft(sewn thru), and another rated at 40F with 1.5" loft) Maybe someone here has a down UQ with only .6" loft that has kept them warm a bit below 50F? Or for that matter the same torso sized UQ that only had 2.5 oz of down insulation including baffles? Anyone? There must be someone?

If not, then I am beginning to suspect that CS is warmer for a given thickness than down of any FP is, even though it might be a bit heavier and not pack as small. But it might be we can not judge the quilt by just looking at how thick it is.

[Five Tango]

I can't speak for everyone but as of now I have been fine while using down insulation in Florida. Granted, all of my down products feature hyperdry/downtek etc.

So I finally sprang for a down TQ and UQ and have no experience with either.Other than keeping my quilts in a water proof bag and keeping the tarp in close enough to my hammock to keep it from being rained on,I am wondering what else I don't know?The thought has occurred to me that wet air itself might be in issue.Should that be a concern or not?Note,I have gone to the feathers in an effort to get my weight down so I can hike instead of just camp;achy flakey back and all that......

[SirMarkos]

So I finally sprang for a down TQ and UQ and have no experience with either.Other than keeping my quilts in a water proof bag and keeping the tarp in close enough to my hammock to keep it from being rained on,I am wondering what else I don't know?The thought has occurred to me that wet air itself might be in issue.Should that be a concern or not?Note,I have gone to the feathers in an effort to get my weight down so I can hike instead of just camp;achy flakey back and all that......

Most down these days that gets used in outdoor equipment is treated to make it hydrophobic. Don't worry too much about wet down, it happens a lot less than you've been lead to believe. Happy hanging!

[mistone]

down is the best for staying warm but cant get wet! but primaloft if gets wet will dry out alot quicker! but want keep you as warm.

[Boston]

...

So in the down over stuff conversation I had found this chart, and I do recall it being familiar. This may have been my reference for the 6 CLO at ~32*F, not an EN rating suggestion (it's been a while since I did that comparison, and I haven't been able to find a reference to an EN rating).

Now I realize that chart is based on total CLO needed, and may or may not be accurate (I have since questioned the author's credibility as a source, or at least in taking his opinion at face value). But, assuming it is accurate - since it's the only source I've found comparing CLO to a temp rating - we still need to account for the clothes worn as part of the sleep system which the down rating takes into account, but I didn't when comparing to CLO of CS Apex. (aka, I assumed 1.75" down = 6 CLO = 32*F rating for the bag, which isn't the case.)

So, let's calculate based off what I typically wear for this temp to sleep: a light weight synthetic hiking shirt, synthetic or wool boxer briefs, 250gsm wool base layer (top and bottom), fleece socks, and a loose knit wool hat. Based on Richard's chart I know this keeps me warm doing light chores around camp (the hat may not be needed). So let's assume this is a CLO of ~2.

I also recalculated my interpolation of the down loft for 32*F, and it comes out to 1.74 (I probably just rounded up for ease of use before, but I have corrected on the sheet)

So, adjusting my base line on the excel sheet I used to do the study (1.74" Down = 4 CLO), I see that the loft of CS Apex would be ~67.3% of the loft of down, all else being equal. This gives 5.0oz/sq yd CS Apex a rating of ~30*F - which seems to coincide more with AHE's rating of 25*F (given the subjective nature of most temperature ratings).

I attached the sheet I used for reference.

[Mouseskowitz]

I grabbed this chart from someone in this thread. There is a ton of good information in there on this subject.