View Full Version : R-value upgrade, is it worth it?
mattjv89
02-09-2014, 16:39
Hey everyone, long time lurker and first time poster planning a 2015 NOBO. I'm planning to start early/mid March to beat at least some of the crowd swell, and honestly I enjoy the woods in winter and will have spent two winters in VT by the time I go so the cold and snow isn't much of a bother.
With a fat tax return now on it's way I'm looking towards this year's round of gear upgrades. I currently have an old Therm a Rest Guidelite pad, which is no longer made but the best I can figure from looking up 12 year old info is that it has a 3.8 R-value. a minimum of 5R seems to be the most often recommended spec for winter, and I've been looking at the NeoAir X-Therm which is 5.7. However, part of me looks at the price tag on that X-therm and thinks 3.8 is pretty close to 5, so maybe it will be enough? since I'm a little rusty on my thermodynamics an R is a pretty abstract thing to me and it's hard to conceptualize how much I'm really gaining or losing there.
So my question boils down to this, given what I have now and the conditions I could be facing would you consider $190 or so for a 1.9R boost a sound investment? I won't go into the rest of my sleep system here as it may change anyway and I keep reading that warmth really starts at the pad.
Thanks!
So my question boils down to this, given what I have now and the conditions I could be facing would you consider $190 or so for a 1.9R boost a sound investment? I won't go into the rest of my sleep system here as it may change anyway and I keep reading that warmth really starts at the pad.
Thanks!
Heck no. If your concern is just R value, pick up a cheap walmart blue pad and dump it once the temps warm up a little. Now having said that, weight can be just as important as R value, and your pad is not very light.
So the question is do you want to carry the weight of your old pad the whole way? or is warmth your only concern?
Also the neoair is a lot more comfortable than your old pad, that may or may no be an issue.
fredmugs
02-09-2014, 17:31
I was just on the fence between getting an Xtherm or an XLite. I went with the XLite mostly because it was on sale costing almost $80 less than the Xtherm and it's about 6 ounces lighter for a Large. I've heard people complain that the Xtherm can get too hot. As long as you have a decent bag you should be fine with an R value better than 3. Like bfayer says you should investigate getting a lighter, more packable, more comfortable pad even if you don't increase your R value.
Drybones
02-09-2014, 17:51
Not certain, but I believe the Exped Synmat 7 UL I use is 3.8. I dont recall ever sleeping cold in a tent using it and I know I've been as low as 15 degrees, actually had to take the long johns off and sleep in boxers at 15 degrees because I started sweating, but I've had some cold nights sleeping in shelters, very cold this past spring, guess that's because the wind under the shelter kept drawing the heat from it. Bfayer had a good suggestion about buying a cheap Walmat pad, the last one I bought was $5.00, use it until you dont need it and then put it in a hiker box, only down side is they're bulky.
Bfayer had a good suggestion about buying a cheap Walmat pad, the last one I bought was $5.00, use it until you dont need it and then put it in a hiker box, only down side is they're bulky.
The blue pads are also great in the snow when you need a place to sit or want to take a nap during the day. There is not much you can do to hurt them. You don't need to carry a full length blue pad, just one that goes from your head to butt. Also, once it warms up you can cut off a short piece to use as a sit pad, and dump the rest in the hiker box. You can cut the extra up and make a pot cozy, or a stove pad for the snow. Very multi-purpose, light and cheap.
Sarcasm the elf
02-09-2014, 18:02
In the winter i just double up and throw a foam pad under my inflatable. My thermarest z lite has an R value of 2.2 and when added to my inflatable the combination keeps me warm enough. I do this while section hiking of course, not sure if it would be convenient to carry a second pad around for the first month of a thru hike.
Drybones
02-09-2014, 18:19
The blue pads are also great in the snow when you need a place to sit or want to take a nap during the day. There is not much you can do to hurt them. You don't need to carry a full length blue pad, just one that goes from your head to butt. Also, once it warms up you can cut off a short piece to use as a sit pad, and dump the rest in the hiker box. You can cut the extra up and make a pot cozy, or a stove pad for the snow. Very multi-purpose, light and cheap.
I saw a hiker who had a blue pad cut to length so it fit in his pack kind of like a liner around the perimeter, put all his other gear inside it. Always thought that was a neat idea on how to deal with the bulk.
CarlZ993
02-09-2014, 23:53
From an R-value stand point, I think your old Thermarest would probably be okay. I used the X-lite pad last year (R-value = 3.2) & had some mid-teens weather that I was okay in. Weight-wise, you could obviously do better w/ the X-therm or X-lite. As the saying goes, 'No bucks, no Buck Rogers.' :)
garlic08
02-10-2014, 00:31
Try a piece of Reflectix duct insulation (http://www.homedepot.com/p/Reflectix-16-in-x-25-ft-Staple-Tab-Insulation-ST16025/100012574) for the few weeks. A full-length piece of that plus my old Z-rest pad works OK in snow for me.
Sierra2015
02-10-2014, 00:39
Try a piece of Reflectix duct insulation (http://www.homedepot.com/p/Reflectix-16-in-x-25-ft-Staple-Tab-Insulation-ST16025/100012574) for the few weeks. A full-length piece of that plus my old Z-rest pad works OK in snow for me.
How much R value do you think that'll add?
1.1 if I'm reading this (http://www.reflectixinc.com/basepage.asp?Page=Performance+Information&pageIndex=730) page correctly.
rocketsocks
02-10-2014, 01:13
for your reading enjoyment...it helped me when I was wondering the same.
http://www.reflectixinc.com/basepage.asp?Page=What+About+R-values%3F&pageIndex=389
http://sectionhiker.com/sleeping-pad-r-values/
Sierra2015
02-10-2014, 01:38
Helpful, helpful, helpful! Thanks for the links. :)
I have tried the reflextix, and R-1 is probably a fair R value for the double bubble. They also sell it in single bubble, so if you get that you will not get the same R value. Unless you have a source other than the home depot/lowes, it cost more than a cheap blue pad, and it does not last as long. It does make better pot cozys and stove pads than blue foam and is easier to pack. The R value of blue foam is a little higher.
Reflextix weighs .8 Oz per Sq Ft. That makes a 48 x 20 in piece weigh a little over 5oz. a chunk of blue foam weighs about 5 oz.
I guess my point is its 6 of one half a dozen of another. I would not try to go without one or the other though, because once you are out there and you are cold, there is not much you can do about it. If you take and find you don't need it, you can chop it up for a sit pad or drop it in a hiker box. An extra 5 oz to stay warm is well worth it to me.
daddytwosticks
02-10-2014, 08:16
I have tried the reflextix, and R-1 is probably a fair R value for the double bubble. They also sell it in single bubble, so if you get that you will not get the same R value. Unless you have a source other than the home depot/lowes, it cost more than a cheap blue pad, and it does not last as long. It does make better pot cozys and stove pads than blue foam and is easier to pack. The R value of blue foam is a little higher.
Reflextix weighs .8 Oz per Sq Ft. That makes a 48 x 20 in piece weigh a little over 5oz. a chunk of blue foam weighs about 5 oz.
I guess my point is its 6 of one half a dozen of another. I would not try to go without one or the other though, because once you are out there and you are cold, there is not much you can do about it. If you take and find you don't need it, you can chop it up for a sit pad or drop it in a hiker box. An extra 5 oz to stay warm is well worth it to me.
You don't have to buy the expensive Reflextix at the big box hardware stores. Go to Walmart or the various Dollar stores and get your self a car windshield shade. Get the truck sized and trim to shape if need be. Works great and relatively light and cheap. Just a bit bulky. :)
garlic08
02-10-2014, 09:31
The windshield shade, I've heard, works well. The mylar layer in that and Reflectix works well to reflect radiated heat, which a blue foam pad will not do. It does not add R value but feels warm. Reflectix is much cheaper if you have a piece left over from an insulating job--it's great stuff for ducts and pipes in crawlspaces where rodents will destroy fiberglass and foams. It rolls up and packs well.
Snowleopard
02-10-2014, 14:00
Wow, winter sleeping pads have sure gotten expensive!
Inflating an air pad such as a Neo Air harder increases the insulation R value (according to tests done by Backpackinglight.com, https://www.backpackinglight.com/cgi-bin/backpackinglight/airmat_sotmr_part2_2011.html#.UvkOmWJdUzA). Inflating harder increases thickness under your weight and increases insulation. Harder inflation might help a bit if the temps turn colder than expected, but you're better off adding a foam pad to your pad.
Reflectix gets part of its insulation from the air layer on each side; if you're using it under a pad you don't have those two layers of air, so the actual R value is lower than you'd expect. Also, comparing R values can get confusing because metric and imperial units are different. Foam pads should work better for the weight. A ridgerest would work even better and a zlite a little less well, but you need to be sure to maintain the air spaces molded into these.
Beware. I can lead a complex somewhat advanced UL backpacking style. I can ceratinly make things more complex that most people want!
Unless you're planning to do frequent deep winter or longer duration deep winter hikes I wouldn't spend that amt of $$$ for a separate dedicated higher value winter pad especially only being 1.9 R value highre. That's just an opinion not necessarily what's right for you. I would simply add a CCF pad or pads to the mix. They come in different thickness with differnt R values and you can double them up to double up the increased CCF R value. That option would be far less expensive and offer more versatilty in set ups but perhaps add some gear bulk. You're only going to need the higher R value for a month to 6 wks or so until you'd prolly want to switch it to a lower R value pad anyhow unless you have even more complex sleeping insulation ideas going forward from that time.
You're saying you're acustomed to the cold. Me too. But that doesn't mean I want to sleep cold. For my winter and winter extended duration hikes when I don't expect temps to regularly go below 5* I get away by switching my normal 3 season thru-hiking Shortie Neo Air X lite(R value 3.2, 47" long) to the Womens Neo Air XLite(R-Value 3.9, 66" long) and throwing a full body length long CCF into the mix. What CCF pad I use depends on my set up(under a tarp, cowboying, in an enclosed tent, hammock set up, lean-to availability, etc) and just how cold I think it will regularly be. Not every AT lean to is built the same but there are definitely warmer shelters and warmer more insulated from convectional as well as conduction heat loses in shelters. In other words, with mindful AT lean to sleeping locations(both in terms of those lean-tos you choose to sleep at and where in those lean tos you sleep) you can sleep a bit warmer. Every little bit can help sleeping warm.
What can also play into the amt of insulation I want under me are other elements in my sleep system(sleeping bag verse quilt, temp rating of either in respect to the lowest temps I expect to be sleeping, sleeping clothes(vest, jacket, thermal bottoms, down booties, beanie/bacalava, gloves, if I plan on carrying dry mix heating packs, etc)
...definitely warmer shelters and warmer more insulated from convectional as well as conduction heat lose spots in shelters.
Check out a women's thermarest neoair xlite. For me its a fair compromise between weight and rvalue. Weights 12oz in the stuff sack and has a 3.9 rvalue.
I actually got an amazing deal on mine. I think they usually run $170 and I ordered an irregular one for $100. The only thing irregular about it was the thermarest logo was smeared. From time to time you can find irregulars being sold.
The Solemates
02-18-2014, 16:23
I just got the X-Therm as a gift. Its pretty swank. Hopefully it will hold up for years to come, but I have my doubts. I'll be trying it out for the first time in the Smokies for a week the first week in March. I'll report back on what I think. Prior to this, I've used a standard Thermarest some-thing-or-other for winter camping that is probably now 10 or 12 years old. It was an irregular as well due to poor logo graphics. I paid half price new - and its lasted me this long!
The womens xlite is what I would have bought for myself, but am thankful for the x-therm gift!
AngelEyez
02-18-2014, 18:47
another idea is to wrap ur pad/bag in a Mylar Rescue Blanket
another idea is to wrap ur pad/bag in a Mylar Rescue Blanket
Wrapping an insulated pad in an emergency blanket does not do much. The insulation in the sleeping pad is already stopping the radiated heat loss. It does help with an uninsluated inflatable pad or a thin CCF pad however. Once the radiated heat loss is stopped, it's stopped. Adding more reflective material will not stop something that has already been stopped.
Wrapping the sleeping bag in an emergency blanket just traps moisture in your sleeping bag. After a couple of nights, your sleeping bag will be next to useless.
If absolutely necessary the emergency blanket could go inside the sleeping bag. That will keep the body moisture from going into the bag insulation. You will get soaking wet, but the bag will stay much drier.
mattjv89
02-18-2014, 21:25
Well thanks for the input everyone, posting a question and getting two pages of advice makes me want to hang around here even more than I already do... For now I picked up a CCF pad that I'll layer under the Thermarest. Still may replace it down the line because aside from the warmth issue I've always found the 3/4 length Thermarest a little lacking for my 6' 2" self, but I've got a year to figure that out. I'll put some miles on this setup and see how it goes for warmth, that is as soon as the 0* bag gets here since my old synthetic 20* bag isn't quite up for February in VT no matter how many pads I put under it...
Well thanks for the input everyone, posting a question and getting two pages of advice makes me want to hang around here even more than I already do... For now I picked up a CCF pad that I'll layer under the Thermarest. Still may replace it down the line because aside from the warmth issue I've always found the 3/4 length Thermarest a little lacking for my 6' 2" self, but I've got a year to figure that out. I'll put some miles on this setup and see how it goes for warmth, that is as soon as the 0* bag gets here since my old synthetic 20* bag isn't quite up for February in VT no matter how many pads I put under it...
Personal experience is worth ten pages of whiteblaze advice. Have fun.
I bought a Klymit Inertia X-frame and it's pretty neat. If you're not familiar with it here's a review:
http://www.backpacker.com/gear-zone-gear-review-klymit-interia-x-frame/gear/15751
Light, and the way it's made allows your sleeping bag to loft under you which works very well. It takes a few nights to get used to but after a week or so I decided it's a winner.
BTW, it works best if you put it inside your bag instead of under it like you'd do a neoair or CCF pad.
I have a Klymit X-Frame as well. Still need to spend some more nights on it to adjust. Trying to decide whether to use it or a basic closed cell pad this summer. The CCF pad can help stiffen the frameless pack I'll be using but isn't quite as comfortable.
Drybones
02-19-2014, 10:26
Personal experience is worth ten pages of whiteblaze advice. Have fun.
+1..................................
Wise Old Owl
02-19-2014, 21:16
Hey everyone, long time lurker and first time poster planning a 2015 NOBO. I'm planning to start early/mid March to beat at least some of the crowd swell, and honestly I enjoy the woods in winter and will have spent two winters in VT by the time I go so the cold and snow isn't much of a bother.
With a fat tax return now on it's way I'm looking towards this year's round of gear upgrades. I currently have an old Therm a Rest Guidelite pad, which is no longer made but the best I can figure from looking up 12 year old info is that it has a 3.8 R-value. a minimum of 5R seems to be the most often recommended spec for winter, and I've been looking at the NeoAir X-Therm which is 5.7. However, part of me looks at the price tag on that X-therm and thinks 3.8 is pretty close to 5, so maybe it will be enough? since I'm a little rusty on my thermodynamics an R is a pretty abstract thing to me and it's hard to conceptualize how much I'm really gaining or losing there.
So my question boils down to this, given what I have now and the conditions I could be facing would you consider $190 or so for a 1.9R boost a sound investment? I won't go into the rest of my sleep system here as it may change anyway and I keep reading that warmth really starts at the pad.
Thanks!
Heck no. If your concern is just R value, pick up a cheap walmart blue pad and dump it once the temps warm up a little. Now having said that, weight can be just as important as R value, and your pad is not very light.
So the question is do you want to carry the weight of your old pad the whole way? or is warmth your only concern?
Also the neoair is a lot more comfortable than your old pad, that may or may no be an issue.
Blue pads are not offered in most stores - it disappeared off shelves two years ago.... ON line only, and I don't think this is the right direction he is looking to upgrade.
Try a piece of Reflectix duct insulation (http://www.homedepot.com/p/Reflectix-16-in-x-25-ft-Staple-Tab-Insulation-ST16025/100012574) for the few weeks. A full-length piece of that plus my old Z-rest pad works OK in snow for me.
Check out a women's thermarest neoair xlite. For me its a fair compromise between weight and rvalue. Weights 12oz in the stuff sack and has a 3.9 rvalue.
I actually got an amazing deal on mine. I think they usually run $170 and I ordered an irregular one for $100. The only thing irregular about it was the thermarest logo was smeared. From time to time you can find irregulars being sold.
good idea.
another idea is to wrap ur pad/bag in a Mylar Rescue Blanket
Some merit there... not sure.
Wrapping an insulated pad in an emergency blanket does not do much. The insulation in the sleeping pad is already stopping the radiated heat loss. It does help with an uninsluated inflatable pad or a thin CCF pad however. Once the radiated heat loss is stopped, it's stopped. Adding more reflective material will not stop something that has already been stopped.
Wrapping the sleeping bag in an emergency blanket just traps moisture in your sleeping bag. After a couple of nights, your sleeping bag will be next to useless.
If absolutely necessary the emergency blanket could go inside the sleeping bag. That will keep the body moisture from going into the bag insulation. You will get soaking wet, but the bag will stay much drier.
My head hurts - Bfayer have you tried any of this? He doesnt need to wrap it - he can custom size it and using some really cool glue permanently attach it to one side... yes it reflects the body's infrared heat, no I would not recommend it inside the bag. Noise, condensation... clammy night. Uh on the first sentence ... on a closed ccf - Thermarest now has a one sided space blanket built in... Honest I don't know - but I can test this with a FLIR and a lazer thermometer.
I suggest some back of yard camping right now - while its cool and a inside outside thermometer, with memory.
My head hurts - Bfayer have you tried any of this? He doesnt need to wrap it - he can custom size it and using some really cool glue permanently attach it to one side... yes it reflects the body's infrared heat, no I would not recommend it inside the bag. Noise, condensation... clammy night. Uh on the first sentence ... on a closed ccf - Thermarest now has a one sided space blanket built in... Honest I don't know - but I can test this with a FLIR and a lazer thermometer.
I am sorry your head hurts :)
Yes I have tried it, and I have seen many others try it and fail. I have conducted the types of tests you are talking about in classes on cold water survival equipment. You can only stop radiated heat once. After it is stopped there are no more gains to be had by trying. A thin CCF is much less efficient at stopping radiation than the thicker open cell foam used in self inflating pads, that is why the silver stuff works on thin CCF pads like the ridge rest. The OP is using a self inflating pad with open cell foam that is 1.5 inches thick. the ridge rest solar is .75 inches thick. Like I said in my earlier post there is some value in an emergency blanket when used with a thin CCF pad. With a thicker pad it adds no additional R value.
This article is not about sleeping pads, but it presents the issue pretty well:
http://www.greenbuildingadvisor.com/blogs/dept/musings/radiant-barriers-solution-search-problem
About the wrapping of the emergency blanket, I was responding to another poster recommending wrapping the sleeping bag, and that is what my comments were addressing. Wrapping an emergency blanket around a sleeping bag will help keep you warmer, but not because of radiated heat loss, but because of convected heat loss. The problem however is the humidity that is released from a body has to go somewhere. As it migrates through the sleeping bag it cools and begins to condense, most however makes it out as vapor, but not all. If an emergency blanket is wrapped over the sleeping bag it creates a barrier to the vapor, and when the water vapor hits the cold surface of the emergency blanket is condenses and traps water between the sleeping bag and emergency blanket. This can kill the insulation value of the sleeping bag very quickly. Might work for a night or two, but not a good solution for multi-day hikes like the thru the OP is planning.
Also, the OP did not say he was looking to upgrade, he was looking to increase his sleeping pad R value and wanted to know if it's worth it to buy an expensive pad to do it. My advice remains the same, no it's not. There are a lot of other reasons to upgrade his pad, but R value alone is not a good reason.
The Walmart near me has the blue pads on the shelf as we speak. $7.98
daddytwosticks
02-20-2014, 08:29
^^ My local Walmart had the infamous blue pads AND two new models of green pads - one being 25" by 72 or 78? Can't remember the length. :)
I have a Klymit xlite and it just doesn't work for me. I use a quilt so the loft pockets dont help with insulting. Im also a side sleeper and no matter how much ive tried I can't get comfortable in it. I feel like I'm on a blow up raft trying to keep from falling off at night and I dont get enough support while sleeping on my side. The upgrade to a neoair xlite was worth the investment for me. Besides sleeping in a hammock it would rank #2 for best nights sleep on the trail. I'm 6'2 and the woman's is 66 inches long and since I sleep in a fetal position it works perfect for me.
The Klymit takes some getting used to and I can definitely see how you could not like it. I hated it at first and was going to send it back but I was just out of Neel Gap and had 310 more miles to hike before I could get home and return it.
By the time I got to Standing Bear Farm I had adjusted to it and it's not a problem now. It's different for sure.
Edited to add: I just noticed you're selling your Klymit after never using it other than in your living room. I can definitely imagine not liking it after never having actually used it. It doesn't give a good first impression for sure - at least it didn't me.
I'm glad I was stuck with it a few days and had a chance to get used to it.
If it doesn't sell soon I may just keep it and give it a couple more trys. Just wondering did you use a TQ with it?
Wintertime isn't the time to rely on an inflatable exclusively. I always carry a closed cell foam pad. But unlike some here have mentioned, it should go ON TOP of your inflatable, not underneath.
Evazote is tops when it comes to closed cell foam (hint).
Wintertime isn't the time to rely on an inflatable exclusively. I always carry a closed cell foam pad. But unlike some here have mentioned, it should go ON TOP of your inflatable, not underneath.
Evazote is tops when it comes to closed cell foam (hint).
It doesn't matter which order they're layered. R value is the same.
It doesn't matter which order they're layered. R value is the same.
Nope, at the end of the day the open air of the inflatable will transmit cold more readily than closed cell...
Nope, at the end of the day the open air of the inflatable will transmit cold more readily than closed cell...
I appreciate that you feel that way, but the physics simply doesn't support your position. It's two layered pieces of insulation. Either order produces the same combined value. There may be other justifications for one over the other, but insulation isn't one of them.
I appreciate that you feel that way, but the physics simply doesn't support your position. It's two layered pieces of insulation. Either order produces the same combined value. There may be other justifications for one over the other, but insulation isn't one of them.
Hey guys, I hate to say it but you are both correct.
CalebJ, You are correct if you are taking about a monolithic insulation, something that has a consistent insulating value throughout its thickness. CCF, Termarest self inflating, Exped Downmat, Etc.
BradMT, You are correct when talking about a non monolithic insulating value. That is a pad that does not have a consistent insulating value throughout it's thickness. For example a Big Agnes IAC, which has a synthetic insulation bonded to one side of the interior of the pad.
In the case of the BA IAC, virtually the entire R value of the pad is concentrated on the one side, if you flip the pad over the pad does not have the same R value. If you use a pad like this with a CCF and you put the CCF under the BA IAC, you lose some R value because of the free air space between the two pads. This free air space allows for convection to the sides of the pad, and then conduction to the outside air.
In the case of a self inflating thermarest, you do not have a free air space, because the open cell foam in the pad fills up the entire interior of the pad. With pads like this the R value is not reduced no matter where you put the CCF pad.
The OP has the self inflating pad, so in his case the CCF could go on top or bottom, but as I stated this in not always the case. How much it matters in the real world, who knows, too many variables.
Starvin Marvin
02-28-2014, 10:47
And what about the X-Therms with the reflective layer inside? Wouldnt you want the CCF pad on the bottom so you get more body heat to that reflective layer?
It's important to remember, most inflatables (like the Neoair) have channels... while the R value is determined from the top or bottom, it's important to remember those channels are essentially open to the sides, contacting cold air and transmitting it more readily inward and upward in the pad. The cold air bisects the pad because of those channels. You can feel the difference in really cold weather sleeping on just the inflatable pad, vs sleeping with even a marginal closed cell foam on top.
It's funny that anyone believes R values in inflatables are not arrived at in a "prejudiced" manner... they're arrived at in a manner to make them look the most appealing to the purchaser, not to give a real number, or to predict how they'll behave in real-world conditions. Just like in the housing world... the R value of fiberglass bats is arrived at with 32*F as a basis, whereas closed cell urethane foam insulation for the same homes has its R value arrived at with 0*F as a basis.
But they're the same R value, right ;)
Comparing the R value of a closed cell foam pad and the R value of an open channel air pad is an excercise in futility as they're not the same thing, and in most inflatables case, can never be. They're apples and oranges despite an "R" figure pronounced by a manufacturer.
pyroman53
02-28-2014, 11:25
In the case of the BA IAC, virtually the entire R value of the pad is concentrated on the one side, if you flip the pad over the pad does not have the same R value. If you use a pad like this with a CCF and you put the CCF under the BA IAC, you lose some R value because of the free air space between the two
You really nailed this bfayer as far as I have heard through many such discussions here and elsewhere. The only thing I would add is supposedly the Neoair products insulate with a heat reflecting layer and it was suggested in other posts by people who seemed to know that putting the CCF on top might defeat this. It makes sense to me though I agree with your points as well.
pyroman53
02-28-2014, 11:38
And what about the X-Therms with the reflective layer inside? Wouldnt you want the CCF pad on the bottom so you get more body heat to that reflective layer?
Beat me to it...nice
Starvin Marvin
02-28-2014, 11:49
It's important to remember, most inflatables (like the Neoair) have channels... while the R value is determined from the top or bottom, it's important to remember those channels are essentially open to the sides, contacting cold air and transmitting it more readily inward and upward in the pad. The cold air bisects the pad because of those channels. You can feel the difference in really cold weather sleeping on just the inflatable pad, vs sleeping with even a marginal closed cell foam on top.
.
Yes, i understand what you are saying.
I was referring to the difference between using a ccf pad on the top vs the bottom, of an inflatable such as the X-Therm. The way i look at it, if i was using an inflatable WITHOUT any reflective material inside, then i would want the ccf pad on top. If i was using an inflatable WITH the reflective material inside, then i would want the cff pad on the bottom.
Why would you position the ccf pad in a way to try to keep your body heat from reaching the reflective material in the X-Therm? What little it may add, it still adds, and does make a difference.
I would want the ccf pad on the bottom to try to minimise the heat loss from the X-Therm to the cold ground.
There is also the possibility that I could have this all wrong. One way to find out for myself, i will be out this weekend and next. Forecasted night time temps between 2*--14* F.
Beat me to it...nice
No... your "reflected heat" is still being cooled by cold air infiltrating from the sides... warm air will still pass from your body THROUGH a closed cell foam and reflect back from the Neoair... but the Neoair should be the secondary, not primary insulator... I've used these things in a variety of configurations, and since Montana is kind of cold, I'm not guessing. Sometimes just because something seems "intuitively correct" does not mean it is.
Snowing right now and we're going to be -15* tonight... :)
No... your "reflected heat" is still being cooled by cold air infiltrating from the sides... warm air will still pass from your body THROUGH a closed cell foam and reflect back from the Neoair... but the Neoair should be the secondary, not primary insulator... I've used these things in a variety of configurations, and since Montana is kind of cold, I'm not guessing. Sometimes just because something seems "intuitively correct" does not mean it is.
Snowing right now and we're going to be -15* tonight... :)
Help us out please. What combination of stuff do you use at, or below, 0 degrees F between your sleeping bag and the ground/snow? If the NeoAir (which model, there are different R-value models) is secondary, what is your primary ground insulation? Specifics from someone who has obviously "been there & done that" is most valuable.
Thanks!
Wayne
Wayne, in "real" cold, a Z rest, in moderate cold a 1/4" Evazote pad.
3/8" Evazote is the equivelent of a Z Rest.
Wayne, in "real" cold, a Z rest, in moderate cold a 1/4" Evazote pad.
3/8" Evazote is the equivelent of a Z Rest.
That is all? Nothing else? A Z rest is only R-2.6. Interesting. Internet folklore & wisdom would indicate closer to R-6 for sleeping on snow. Thanks for the real world information.
Pondering my sleeping pad upgrade.
Wayne
That is all? Nothing else? A Z rest is only R-2.6. Interesting. Internet folklore & wisdom would indicate closer to R-6 for sleeping on snow. Thanks for the real world information.
Pondering my sleeping pad upgrade.
Wayne
Wayne... that's on top of an R3+ Thermarest... it works.
Would add, I've slept on the bare snow with a single 3/8" Ensolite pad at -15F... experience trumps guessing or internet experience.
Thank you. Shopping for a new pad combination just got cheaper.
Wayne
Would add, I've slept on the bare snow with a single 3/8" Ensolite pad at -15F... experience trumps guessing or internet experience.
The problem with that statement is that there are people on both sides of this issue with all sorts of experience in cold weather climates. You can't just dismiss all of them because you disagree.
Wilson2016
03-01-2014, 04:41
Can everyone here honestly say that you could sleep on the hard cold ground if the R VALUE
Wilson2016
03-01-2014, 04:45
met a number. Isn't comfort part of the equation? IMHO you have to include sleep. Does a quarter inch of hard foam really do it for you guys?
lonehiker
03-01-2014, 08:41
met a number. Isn't comfort part of the equation? IMHO you have to include sleep. Does a quarter inch of hard foam really do it for you guys?
When I was younger maybe, but now I take a closed cell (walmart) and use it in conjunction with my neoair. Both are 3/4 length.