There is a new thermarest coming out! 2.5 thick, 2.5 r value, but only 14 oz for reg size! I'm new to hammock bacpacking but experiecned in backpaking by way of ultralighting. This new pad looks good. I hope its as good as the specs show. Here is a link. http://www.thermarest.com/product_de...?pID=134&cID=1 Can anyone think of any negatives about this pad before I spend my hard earned $? I have a eno doublenest. There is a 25 inch wide model too. would this be better? Thanks for your replies!
I have been aware of it for a couple of months but have never had my hands on one. It is interesting and unique... it is a lot of partially compartmentalized air pockets that are stacked and use reflective material. My first thought when I saw sketches of what they have done was there was a lot of structure to it and what a challenge that would be.
I also wonder about the R-value for it and how they determined what it was. I thought R-value was specific to insulation that only had conductive heat transfer properties. This thing looks to me like it has a bit of all three heat transfer properties. When searching the web about radiant barriers for insulation over the years, there seemed to be issues about how to characterize radiant barriers insulation comparatively to fiber insulation that is more commonly used and is characterized by R-values in some way. (For reference to those that might care, the 3 methods of heat transfer are conductive, convective, and radiant which are by physical contact, fluid movement, and electromagnetic energy, respectively... if I am remembering correctly.)
Youngblood AT2000
If it were me, I'd save the money you're going spend on that pad and put it toward a nice underquilt. Don't worry, it's ok........you can thank me later.
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I was plannig on 3 season use with most being in summer. REI dividends are coming out to members so I can get it for free. Plus I still plan to tent camp when going with non hammockers. On the R value ( the most important feature to hammockers) I agree that it seems to use all 3 forms of heat transfer. So basically this pad will have the about the same r value as the popular ridgerest without all the bulk, which is what I'm after. And its weight...simply amazing to me. I want to stick to ultralight stuff, which is how I became a hammock hanger anyway. Would ya'll go with the 20 or 25 wide model?
If you're determined to go with a pad, get the wider 25" option, IMO.
"If you play a Nicleback song backwards, you'll hear messages from the devil. Even worse, if you play it forward, you'll hear Nickleback." - Dave Grohl
Don't know about picking the 20 or 25 inch wide models... actually you have 4 sizes to choose from. I don't know if a 20 or 25 inch wide model will keep your shoulders warm all by themselves in a hammock. Certainly you have a better shot at it with the 25 but it might not be wide/thick enough to keep the hammock off your shoulders.Originally Posted by Carolinahammockhanger
For reference, I have used a 3/4 length ridgerest for 40ish degree weather with a small pad (10x20?) in the foot pocket on my sleeping bag/quilt and a SPE with clothes or small pads in the wings. The wings make it about 30 inches wide and that is about minimum width for me in a hammock at my shoulders. A lot of the decision to use a 3/4 length is the bulk issue of the ridgerest. The ridgerest is about the same weight and has similar specified R-value numbers.
Youngblood AT2000
We all know that staying warm is very much an individual thing. But I just can't help thinking that these specs are a bit of overkill. There are many here whose 1/4" or 3/8" pads take their sleep systems into the 30's or 20's. What would a 2 1/2" pad allow? Quite a bit, I imagine and maybe more than is necessary/faced on the trail. The 14oz doubles the weight of my pad which gets me to the mid-20s (and mine is 40"X60").
This ThermaRest may be better suited for the ground than a hammock, IMO. But comfort is very much an individual thing, too, and there's lots of variables...
FB
i'm skeptical as well, the reflective material inside might do well when incorperated with the air space, which is how the heat reflective materials are best used. but i wonder how they test for r-value. my guess is the fill it all the way up to 2.5" or whatever the max thickness is and test it like that, wheras when it's actually being used, your weight compresses it a good deal in certain spots like under your butt and back, it's not going to be full thickness there, and from what i can tell, less thickness in an air pad does decrease the warmth, even if it's just in certain spots.
To draw on a conversation on the Thermadrape thread, would placing a Heat Sheet/Thermadrape inbetween the 2 layers of a hammock reduce the insulating properties of the reflective material?
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IMO, I believe the trick with any reflective material is to have an empty space/air gap between the reflective material and your insulation.
Putting the VB between the 2 layers of a hammock wouldn't necessarily reduce the insulating properties of the reflective material, as the material really doesn't have much "insulative" properties on its own. It is when a reflective barrier incorporates other techniques that it starts to become insulative. And the closer you are to the outer layer of your reflective barrier, the more likely you are to lose as much heat through conduction as you gain through radiance. It's like the difference between a divers wet suit or a dry suit. The wet suit incorporates a layer between the vb insulator and your skin, whereas the dry suit directly contacts your skin. The wet suit stays warmer, as it has a medium to heat between you and the outer layer. Eventually, the surrounding cold water will draw the heat out of even a wet suit through conduction by direct contact. As the outer layer cools, the inner layers also cool.
I use my thermadrape as a VB insulative layer. When used as a UQ, airgaps between the hammock body and the outer layer of the Thermadrape UQ occur naturally, just by the hang of the UQ, exactly the same as a down UQ works by creating a dead insulative space where the air is allowed to heat and slowed from dissipating. Does it replace a down UQ? I wouldn't recommend it to most without some other kind of insulation layer, which could include clothes, a SB, another light UQ or even a sock over the hammock. Would it replace a Pad? I wouldn't use it in the pad pocket, for the reasons stated above; but yes - I think it would. If you sleep down to the 20's with nothing but a pad and a SB in the hammock, IMO you could do it with either a Heat Sheet UQ or a Thermadrape UQ. Even better, with a Heat Sheet UQ/Thermadrape UQ and a pad you would really get a heat boost, and could probably forgo any other kind of bottom insulation, except in Shug conditions. My .02.
Last edited by fin; 02-19-2009 at 08:44. Reason: Taking into account insulation to prevent conductive and convective heat loss
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