1. ## PrimaLoft Ratings

A while back I made a PL TQ and UQ using a 7oz weight PL. At the time, an accurate temperature formula had not been devised. I've been out of the loop and wondered if anyone came up with anything?

I plan on running a few tests since its getting pretty cold over the next few days. Just to get an estimate, I'll hang outside during the day and see if I am able to remain warm. I'm hoping that with some clothes I'll be good to around 20F.

We'll see.

2. I think it depends on which type of primaloft you're using. For primaloft sport I think it is something's like 55-(total oz per yard x 5). For example my UQ is 7 oz like yours. 55-(7x5)=20 degrees. I've not been quite that cold but I have been down to 29 and been toasty. In other words, it may not give you an exact number, but it should give you a pretty good rough estimate.

3. I imagine you'd be good to somewhere below freezing, like soccer dude just said. A note about hanging during the day: You'll probably have the sun to warm you, and your own metabolism will be higher. Give your body at least an hour to "calm down" after you get settled to get a better estimate of the rating.

PF

4. Yea thats close to the formula I got from some post somewhere 60-(oz/ydx5)=temp

5. Thanks guys.

PS-PuckerFactor = PL God

6. There is a great wealth of information about Primaloft on the Backpackinglite website. But, the one thing I got from it is, that it takes twice the weight of Primaloft to equal the weight of down. I'm not sure how the 'loft' thickness fits in with Primaloft vs. down.

7. Can you use "CLO" ratings to get you in the ball park? And what "type" Primaloft is it?

Ayce from Thru-Hiker says:
In a well sealed bag with good ground insulation

clo 2 @ 40 deg
clo 4 @ 20 deg
clo 6 @ 0 deg

There are a lot of variables in play that can have a big impact on that chart: use it without blinders.

Quilts have trouble below freezing. Make sure you design in a good way to seal it up.
Also from his site: http://thru-hiker.com/materials/insulation.php
I see he has Primaloft Sport with a CLO rating of .79 per oz.

So, with Sport anyway, 7 oz/sq.yd X .79 CLO per oz= CLO 5.53

Which as you can see results in a rating WAY warmer than what is being suggested by other users experiences. And some one like Wiggy would ridicule the concept of CLO.

However, using CLO to guestimate warmth with Climashield does seem to give pretty accurate results for several folks at HF. For example, using 1 layer 2.5 oz CS in the WB UQ, with a CLO of 2.05 ( I think it was CLO .82/oz) kept me warm in mid 40s with nothing but cotton t-shirt and jeans, though I did feel I was at the limit. While I (and family members) have used it with more layers at colder temps, none that could test the CLO ratings because we did not approach the theoretical limits. However, Cannibal did take his, with a CLO of ~ 8, to minus 11F with plenty of base layers. See post #3:

I suspect we might need a little more CLO ( or loft with down) for UQ ratings than TQ. But if things work the same with PL as CS, find out what the CLO rating is for a ball park guess.