Originally Posted by blackbishop351
You've got a 3" loft quilt? What do you mean by "both layers, top and bottom"? As far as I know, if it has a top and bottom it's a sleeping bag, not a quilt. And you don't think 3" is enough? Depending on the specific type of insulation (as discussed above) a 1.5-2" quilt will give an average temp rating of 30*...
As far as wet performance with down vs. synthetic, I also read that BPL article about loft retention. The problem with that analysis is that again, the insulation value of synthetic has little to do with loft. Do you have a link to the side-by-side comparison you found? While far from a lab-standard test, it seems more reasonable and I'd like to take a look. That's the first test I've seen that even attempted to look at overall insulation value rather than loft.
By the way, measuring the total loft (top and bottom) of a sleeping bag is pretty misleading...even on the ground, you're compressing the insulation that's underneath you, and thereby losing a lot of its value.
Well the back is normally open except under the lower legs and feet. It won't open flat though, the bottom is permanently closed. So since I am used to sleeping bags any way, and since it is hard to get it to lay flat since you can not fully open the foot box, I just layed it on its side so that each back edge was touching, as it would be if I pulled the draw string and pulled the open back all the way closed. That equalled 3", and is similar to trying to measure a sleeping bag which you can not open. I'm going to see later if I can lay it flatter and just measure the thickness of one (the top) layer. I guess quilt is not the correct term since you can't lay it completely, only almost, flat. I guess it wuold be more of a semi-rectangular bag. One in which you can open the back (above the hips) up almost completely if desired, or cinch it almost closed. There is also a draw cord around the neck to cinch that closed. My guess right now is that the layer of loft that will be over me is about 1.5".
I guess the "clo" would be whatever PG delta is. Although this is PG 180, while the clothing is PG 60, whatever that is?
BTW, the "lab" comparison was limited to loft before and after saoking, measured every 20 minutes. The real life test was sinply who was cold or not cold with wet insulation.