How many degrees would a climasheild quilt add to a 15d bag

10* for 2.5 im guessing
just add the loft to the BPL statement on sleeping bag loft graph and you'll get a good guess (maybe a little overestimated)

Not exactly your situation but I use two quilts;
* 6oz PL1, sized about right for me
* 2.5 oz Climashield XP, about 4 inches wider than the other.

I use them alone or together depending on temps I want to prepare for:
* 2.5oz alone … not yet enough experience to know the limit
* 6oz PL1, I start to feel cool somewhere around 25*F
* the 2.5oz over the 6oz, I start to feel cool somewhere between -5*F and 0*F

edit: The tests of the two together were in a bivy. The others were not.

edit#2: I have one single data point where I was toasty warm at -13*F in a bivy on a foot or so of snow, using a ridgerest pad on top of a 1/2" bluefoam pad using a 30*F bag (Marmot Arroyo) topped by both quilts. That was definitely not a lower limit of that combo.

Troy,

A 2.5 oz Climashield XP over bag will result in an EN13537 LLimit rating, for the combined bags, of ~-6.5F.

The closest equivalent Climashield Combat insulation is 2.2 oz. This will result in an EN13537 LLimit rating, for the combined bags, of ~-.6F.

I thought the Combat climasheild

3.7 oz/sq yd: @.9 " loft. clo=.78/oz. 60 inch roll width. Price: $10.95

was thicker than the 2.5 oz insul ??

2.5 oz/sq yd: @.6 " loft. clo=.82/oz. Total CLO : 2.5 oz * 0.82 clo/oz = 2.1
60 inch roll width. Price: $9.95

.9" vs .6" so wouldnt it make more of a difference than 1/2 degree ??

??

combat comes in many weights, not just 3.7oz. However 3.7 is the only weight i know of that is available to the home gear maker. So it would be warmer than the 2.5. (he was showing info for combat 2.2oz)

-Tim

And to clarify, I think Richard's post says -6.5 degrees versus -.6 degrees, not versus -6 degrees. The difference isn't half a degree but more like a six degree difference for the 2.5 oz versus the 2.2 oz.

So if 2.5 oz Climashield is good for -6.5F with my combo, what would 3.7oz combat get me.

I am thinking the 3.7 quilt alone might make a better fall, spring bag, although a little heavier.

I had a 5 yard sample of 2 ounce per sq yard Climashield Combat. It turned out to weigh about 2.2 ounces per sq yard. I made a quilt out of some of it and using that quilt inside my Pertex Quantum and Cuben Bivy slept warm down to the low temperature of the hike at 42 degrees.

I was wearing top and bottom Patagonia #2 Merino wool, hiking socks, a wool hat, liner gloves and sleeping on two 1/4" GG pads.

Your sleeping bag is only as good as the system. That means your sleeping pad or what ever is between you and the ground is just as important as your sleeping bag.

Got it.

I have a full length blue pad, and a short thermorest prolite I put on top.