That rating is based on laying on the ground so that's with a grain of salt in a hammock. Very true on the relative rating difference though. The down insulation is definitely warmer.
I just went winter camping with my son. I was in between hammocks at that point and we used a tent . Anyhow, I used my Big Agnus insulated pad and he used a 3/4 Thermarest. I think it was in the upper 20's and I froze my butt off. The cold was coming up from beneath me. I stole the small CC butt pad he was using under his feet and also had mine to use (he did have my booties on). After that it got much better. I have already returned one BA because the laminated insulation came loose. Hold yours up to the light after inflating it. If you see variations in color the insulation may have come loose. I believe you also have to use them with the tag side up to have the insulation against your skin, otherwise it's a whole lot of air to keep warm. I don't think the BAs are that warm. I'll never take mine winter camping again. Stick with adding a CC pad in those high compression spots.
RAW, back a few years ago when POE and I guess Big Agnes first came out with their insulated air pads I took a look at the one POE had. Now that is a while back and what I found then may not be what they are doing now, I don't really know. I was under the impression that both where doing what I was concerned about basically the same way.
What they were doing was gluing or attaching in some way sheet insulation along one of the inside surfaces. That insulation did not fill the whole volume of the air pad. That created an interesting product with unique properties. It had conductive insulation (the sheet insulation) and a big air pocket where convection ruled all in the same package. I would guess that if you laid on top of it in a hammock with the side with the insulation against your back it might keep you warm to 40F(?), but if you flipped it over in might only keep you warm to 60F(?). That has everything to do with that big air pocket and how convection works.
Another interesting aspect of that was stacking pads with it. You had to start out with the side with the insulation up and you had to add whatever closed cell pads you where adding to it on top of it to get the additional insulation from them. If you put the ccf pads underneath those insulated air pads that big air pocket would just about make them useless.
You may have been dealing with that, I don't really know, but if you are you can get frustrated, misled on what is going on, and cold. A big air pocket allows large convection currents and is a little like venting-- if doesn't help a whole lot to put a lot of insulation on the other side of a vented area or a big air pocket.
When I would slide my hand under the pad near my butt, the hammock surface didn't feel nearly as cold as down by my legs. So I started to hypothesize that the air pad was pulling my heat away from my torso and releasing it down by my legs.
And I'm also glad you pointed that out about the CCF pads, cuz that means I've been doing it wrong. I've been putting the GG pad underneath the air pad, with the airpad's insulation up against me. I didn't know that wasn't the way to do it.
I'm gonna try out a downmat from a generous HFer. But for tonight, I'll put the GG pad on top of the air pad and see how that feels. I just hate how I can't slide on the GG pad. I now see why people love the double-layer bottom hammocks.
And another thing:
I think I'll be looking into the heavier heatsheet, or thermadrape, or wonder window. This mylar thing didn't boost the temp as much as I would have hoped as a vapor barrier underneath me.
A friend of mine was cold on the ground with one of those BA insulated pads at 14*F, but that may heve been more the fault of he bag he was using.
Is this a Clark hammock? Do you have some type of insulation in those pockets?
Last edited by BillyBob58; 02-24-2009 at 17:21.
Apparently, signature that I used from 2006 no longer tolerated so now deleted.