This really is the most scientific approach to backpacking I've ever seen. Clearly a five star channel.

@GearSkeptic

5 ай бұрын

Thank you! It's far from perfect, but I try!

This is SO the video that we need today, especially with seemingly everyone starting to carry yet another electronic gadget that’s just not needed.

Nothing is more exciting than receiving a Gear Skeptic video notification.

As always, Thank you. Too much of what we believe is marketing. Someone who looks for facts and evidence to support it is a rare and precious commodity.

@GearSkeptic

5 ай бұрын

Thanks! And, you are always welcome.

Your videos are OUTSTANDING! Id love to see a comparison of warming/cooling/wicking base layers, mesh, merino, synthetic etc. As only you can do, of course...

@GearSkeptic

5 ай бұрын

Working on clothes!

@freeforester1717

5 ай бұрын

Brynje Norwegian string like base layer is warmer than merino, very warm indeed.

Thank you for this. I am one of those people who perpetuated the dogma about not blowing into an air pad. Which is ironic because I often talk about not blindly accepting these type of unsubstantiated wisdoms. A good prompt to examine what I am saying myself. Having said that, the small pumps still make the inflation job easier😉. Thanks for sharing

@GearSkeptic

5 ай бұрын

Must say, the ease of a pump grows on you. I found it useful for drying out the pad after testing. Use pump to fill, leave over night to evaporate inside, deflate the next day. No need to lay on it that way.

Gotta thank you for this one. I was very worried about mold growth in an insulated pad, and it's been keeping from getting one. I saw that same patchy pad photo and thought I would need a pumpsack or portable pump. Thank you for clearing up misunderstandings on the topic so thoroughly and objectively.

@jonathanshaw6784

5 ай бұрын

Fwiw a portable pump isn't very expensive, is fairly light and is easier than your breath.

@GearSkeptic

5 ай бұрын

Glad I could help!

@mtadams2009

5 ай бұрын

I have use a Neo Air for over ten years. I have never used anything but my breath and I have never had an issue. I think people worry about the craziest things.

@DawnSentinel

5 ай бұрын

​@@jonathanshaw6784 I've never really understood the appeal. If I'm fit enough to hike for long enough that I care about going ultralight, I've never found inflating a pad to be very taxing. It takes about 30 secs to 1 min and it doesn't leave me deliriously out of breath or anything. I also don't have that much stuff I need to do at camp, so it's not like I'm saving significant portions of time by doing things in parallel. It's also more stuff to charge, break, and add complexity to kit, which are all things I try to minimise when possible.

As a scientist who likes backpacking, I salute your approach. You have a new follower! There is a lot of marketing & hearsay in the community, so we desperately need some mythbusting.

@jorisev

5 ай бұрын

In addition: i am curious about treated vs untreated down for quilts and sleeping bags.

HELL YEAH! THANK YOU FOR THE NEW POST!!🎉

This is brilliant, thank you. My number one reason for using either an inflation bag OR pump has more to do with the fact I feel really, really, dizzy after inflating my mattress by mouth! Thanks again

@GearSkeptic

5 ай бұрын

After all this inflating...that pumps keeps looking better! ;)

Lets go!!! Excited to watch. Would love to see a video on Natural v Synthetic clothing and what is the best for durable and sustainable options.

@CrowMagnumMan2024

5 ай бұрын

Yes that is a great one.......must include....if you use synthetic insulated gear it keeps you warm when soaking wet......smh......Im sick of hearing that.....!!!!

@GearSkeptic

5 ай бұрын

Already started thinking about clothes 😉

@whereisthemessiah

5 ай бұрын

​@@GearSkeptic 🙌

Great video. I wish more of the internet was this well considered, researched and reasoned. The world would be a better place!

@GearSkeptic

5 ай бұрын

Thanks! Much appreciated.

Somebody is going to ask me why it took half an hour to brush my teeth.

@StevenKeery

5 ай бұрын

Allwaysareup: What big teeth you have Grandma.😂

delightful breakdown and discussion. Thanks Gear Skeptic for being such a great voice in the outdoor gear comunity

@GearSkeptic

5 ай бұрын

Much appreciated! Thank you kindly.

The main idea I’ve heard regarding inflating a sleeping pad with your breath in very cold sub-freezing temperatures is that the warm breath will contract as it cools and further inflation will be required to retain full inflation and therefore full R-value. I’ve not personally heard debate about internal condensation compromising the R-value, only debate about condensation and mould. Anecdotally, I live in a cold, humid place and rainy trips of several days can introduce visible internal condensation even using a pump sack with the humid air. My pad gets a funky smell on trips like this that I notice when I deflate it, but airing the pad out at the end and cycling air through several times dries it out fine and gets rid of the smell.

@mreverythingelsewas

5 ай бұрын

Came here to say this as well. I've always heard that the contracting of warm breath in cold environments would reduce inflation and thus R-value.

Time to return my flextail pump and save 45 grams and give everyone their quiet back .. ..😅

Thank you for continually scratching that itch! We all benefit greatly.

Wow!!! a pair of talking hands. One of the best videos I've seen on the subject, and it aligns with what I have thought for many years. Cheers from the mountains of NZ ☺☺

Probably my favourite outdoor channel period. Thanks for doing what you do. I will continue to refer people to your content!

@BradyPatterson

18 күн бұрын

Oh, and I carry a pump because I don't enjoy being dizzy from blowing up my massive Exped pads.

@GearSkeptic

18 күн бұрын

Very kind of you! And I can’t disagree about the convenience of a pump 😉

Thank you for another great video. Your hard work and dedication are greatly appreciated. Please keep making videos. ❤

@GearSkeptic

5 ай бұрын

Thank you! Just glad if any of it helps.

Excellent video and wonderfully realistic clinical approach. I love this series and find it very helpful for people to have piece of mind. You’ve got a new sub and cheers! 🤙🏽

So happy to see this. My S2S UL pad has taken 9 years to start to show mould growth. I think that’s a pretty good life span for a sleeping pad (and I’m still using it - mould and all)

@fayleya3865

5 ай бұрын

Edit to add: but I’m not going to cut it open to check if what looks like mould actually is mould 😂

Loving the content! Keep it coming!

I love your videos man, you're that kind of people we need more! All that effort to get the result as neutral as possible, based on real facts (as good as possible), that's the way! Thank you so much for all your videos!

@GearSkeptic

5 ай бұрын

Thanks much! Plenty of room for improvement, but I try!

Thanks again for your work. I love facts❤️

Once again, thank you for the excellent scientific presentation. This is some of the best content on YT.

@GearSkeptic

5 ай бұрын

Thanks much!

Thank you for all the hard work! Helpful and fun video!

I love the detailed, logical approach. I also kind of enjoy that you talk with your hands. It's a unique form of expression!

@GearSkeptic

5 ай бұрын

🖐🏼🤚🏼😉

Great video and as usual full of sound logic. Really love everything you have put out and your nutrition and hydration series are fantastic as well as the new windscreen videos. They have helped me make more informed decisions, and to some degree relief that I haven't been far off the mark all these years. For me, I do use a pump, in fact, the very one that you show that I got at the beginning of the year. At least in my case, it has nothing to do with moisture or humidity, it's a time and breath saver. Put up the tent, attach the pump, and do something else with my time. Also no feel lightheaded as I blow it up. It's an unnecessary but small luxury item that to me is worth it.

@GearSkeptic

5 ай бұрын

After all this inflating, I’ve begun to see the attraction to a pump, as well 😉

I LOVE your videos. Thank you for these, and the sense of humor :) I find them very helpful.

@GearSkeptic

5 ай бұрын

Thanks! I’m very glad.

Well done, Well thought through, and Well said.

That was very thorough and clear. Impressive!

This is my new favourite channel

@GearSkeptic

5 ай бұрын

Thanks much!

Another great video! I can't wait to see what you debunk next.

Your content is like engineerguy on youtube. Substance in every sentence and you got the facts to back them up. You even sound like him. Great videos!

Excellent, I have watched a few of your video's in the past...new sub now. These are great examples and I really appreciate the effort done to prove / disprove the marketing research or trail legends.

@GearSkeptic

5 ай бұрын

Thanks!

Your academic, ahem, scientific approach is so desperately needed nowadays to help sort through the noise. Thanks for all you do.

@GearSkeptic

5 ай бұрын

Much appreciated!

Thanks for the investigation! I always had my doubts and by doing some field testing I never experienced any negative results of blowing my pads up with my mouth. Bud it's nice to get some more information and deeper testing on this topic. Stay warm and cozy!

Another great video! Well researched and presented! I am friends with and backpack with Devin, who is Backcountry Exposure. I can vouch for his video and his credibility. I think you have cleared up this mold myth! Also the R-Value issue with humidity from your breath. Thank you for another great video! The reason I got the zero pump is I’m tired after a long hike and was the luxury of having a pump inflate it for me. But I did not buy it for a warmer pad experience or to cut down on mold growth.

@GearSkeptic

5 ай бұрын

Indeed! As far as luxury items go, a pump is one of the lightest. Thanks much! Devin is a good egg, been subscribed for a while now :)

Nice video. Did the AT last year and at first used breath then pump sack and personally, both methods suck. Especially after a long day on the trail. Purchased a small FlexTail and it made a world of difference to me. For me, having the means to connect the pump and start inflation while I do something else was a small game changer.

@GearSkeptic

5 ай бұрын

One of the lightest luxury items you can carry!

Greetings 👋👋 OK…. I hardly know where to start. I’m not sure now if this enlightening video was the first of yours that I watched, cause I’ve watched so many now. But in any case thanks. I’m not really a backpacker but a 75 year old who motorcycle toured and tented back in the 80s, got away from it for 25 years, and now hammock camping out of an inflatable kayak. So limited space. Your videos on stoves, filtration, etc so helpful.👍 I’m gonna try say this respectfully and tactfully 😊…. Your videos give me “more” information than I need but you present it SO WELL that I take it all in….And enjoy it. And I think of the time you invest in these and I truly wish there was a way to get more eyes on them so more folks could benefit. Maybe you have to click bait the title with “Naked backpacking with NO bug spray “ or something as silly. In any case..thanks so much for doing these.

@GearSkeptic

4 ай бұрын

That is very kind of, and is much appreciated! Pretty sure that “naked backpacking” in my case would scare away more people than it attracts 😱

It always amazes me when people say “you must use this new device”… and it never seems to occur to them that human race got right here without that device.

I am a retired engineer and I really appreciate the data driven approach to backpacking provide here. It was interesting to see a reference to a data source I often used in my career. Btw an obvious way to avoid the pad issues is to use a hammock instead of a pad and tent system. But that’s just me. Again, great video. Hope there will be more like this.

@kevinstarski1598

5 ай бұрын

Relying on finding 2 trees at a proper distance to set up your hammock...hmmm...I wonder what can possibly go wrong in that scenario

Another fantastic video. Thank you very much.

Thank you for making this video and doing all of your research. I have never used a pump and always thought this mold issue was nonsense and it’s nice to know the facts. Take care

@PaulSchortemeyer

5 ай бұрын

Agreed!

Great video as always. Just a food for thought. The only scenario where humidity could affect heat loss, would be at really low temperatures. How? Latent heat. If humidity causes condensation on the inside surface and you would touch the same surface with your body from outside, warmth of your body would make the moisture EVAPORATE which will drain some heat from you. That vapour would condensate again on the surface you are not touching and as everybody moves in the sleeping bag on a mattress, this process would repeat itself. However, the amount of water is not big so this heat loss will be probably still negligible.

@GearSkeptic

5 ай бұрын

I like your thinking! As you say, it's a small amount of water. Be tough to guess, and even tougher to test. Baffle design will make a pad's reaction to motion-induced convection highly individual. I suppose if it was cold enough for the condensation to freeze, then it won't circulate.

@bulko89

5 ай бұрын

I was thinking the same. How much is a pad like a heat-pipe? Without wicking the moisture back to the hotter part, not so much I agree so it is only movement that makes you contact water. I felt like this was maybe missing from the discussion so far before I saw your comment. I also agree the effect should be too small to really matter.

Great work, thanks

I love your videos, but as an chemical engineer, I would refer you to heat transfer text books. There are 3 forms of heat transfer, conductive, radiant, and convection. I think you were correct at focusing on thermal conductivity of humid air. Convection likely dominates the others. As the air circulates in the air pockets it will transfer heat from the warm side to the cold side. I agree that neither the humidity nor condensation will affect the heat transfer.

@GearSkeptic

5 ай бұрын

If you add convection it gets complicated quickly. Motion-induced convection would be very hard to test, and very particular to the exact baffle design of each individual pad.

Great video, great channel.

Great explanation!

Great stuff 👍

Great analysis, definitely a new subscriber! Have to check out your other Fact Checker videos.

@GearSkeptic

5 ай бұрын

Thanks much!

I've recently discovered your channel and find the data driven and unbiased analysis fascinating and truly helpful. I'd like to support your work for the knowledge you've provided me and was hoping you had a merchandise page or a Patreon available but there doesn't seem to be anything. Looking forward to your next upload. best regards from the UK!

@GearSkeptic

4 ай бұрын

Thanks much! The sentiment of support is very appreciated but not necessary. I just hope some of the videos can be of help!

Very cool, informative and entertaining . . . 10 breaths for me but I use a medium. I deflate my X-Lite mattress while I'm still lying on it and the air in the mattress is warm so it carries the humidity out when I deflate it as your experiment suggests. Even the ground is warm when I feel it. I have never slept directly on snow so I doubt there's any condensation. Every once in a while I would blow it up and set it in the sun for a while and then deflate it but it seems that's not really necessary and the mattress never did get any funky smell to the expelled air suggesting nothing is growing in there.

Thank you for all the work.

@GearSkeptic

5 ай бұрын

Most welcome!

Learned to use my nylofume pack liner as a pump sack which I’m already carrying and only top off with a couple breaths. Avoids the myths 😂, and does have the real benefit of at least filling with ambient temp air rather than warm breath. That helps with air pressure inside the pad as it normalizes in my experience. Thanks for your work!

Planning for a 3 nights winter ski travel in Canadian snow using a 33 YO Therm-a-rest. This video is soooo useful! Thanks!

Thank you! Again, as always! So good and tons of fun! My two thermarests, tiny pump, and older lungs thank you. Now I can officially proclaim the tiny pump ‘just’ a luxury item.

@BottomLineBassin2

5 ай бұрын

It's still good for fire

@GearSkeptic

5 ай бұрын

I won't lie. After inflating that pad several times in a single day, the old pump starts looking better!

at last somebody who asks himself questions and questions all those clichés served to us by just about every influencer on youtube. great job. ciao from Venice (Italy)

@GearSkeptic

5 ай бұрын

Thank you!

Super interesting, thank you!

Mission Accomplished! Great video as always, though I am surprised that there is little to no research in this area. The mold issue was something that I was always a bit worried about, but I figured that as long as I did not suck the air from it, it does not really matter.

Awesome! Like always is!

Great video. I never bought into the mold theory as the pictures shown to be mold were mostly delaminated Xlites.

Another great video. I send every hiker I meet your way. I do have a single anecdotal case of moisture build up in a pad. A fellow hiking buddy on the AT had considerable moisture build up in his pad, actual pooling could be seen in it by the end of trail. It is however the only case I have ever seen. I also saw a single case of mold, but watching this video it was likely just the inside coating wearing off. I still use a pump sack because blowing up a pad is exhausting as the end of a long day, especially at high altitude, I get very dizzy.

so appreciated!

You rock. Thanks for sharing this

@GearSkeptic

5 ай бұрын

You’re very welcome!

Another great video as always 👍 (and for anyone else wondering as I did initially about why then the heat index goes up as the relative humidity climbs, the answer is because of less evaporation of sweat rather than high heat transfer from the humid air)

@GearSkeptic

5 ай бұрын

Nice! I have thought about this from time to time, but it never bothered me enough to carry the weight of an inflator. Now it won't even bug me any more.

👍👍👍 .. another good one 😊. 'Possibly' in the distance, the sound of the gnashing of teeth from manufacturers of said 'pumps' and such. However, only a Sceptic would be able to prove / disprove that mantra 😏. Thanks for the research and the share ..

These are great! The algorithm finally decided I need to know about your channel and I am catching up. Another camping sleeping associated heat loss that has differing opinions is whether to get up and pee (and jettisoning 800 ml of, presumably, already warmed water) or hold it and its heat in. My personal practice is to keep my reliably sealed pee bottle inside my bag as a hot water bottle (I also hike solo so I am all about risk taking :)

Great video, as always. And very timely given the volume of pump zero ads I see. I’ve been use the pump sack that comes with the Xtherm, but if it’s not windy I have to blow into the sack a bit anyway. Now I know I can dump the sack and just blow straight into the pad with no worries.

Interesting discussion/video. I've used self-inflating pads on two thruhikes and lots of other trips including winter. Always wondered about the effect of inflating, but never had any problems I could relate to moisture buildup. I've had one Thermarest delaminate partly creating a big bump in one end. Had it replaced for free though so couldn't cut it open to examine the inside. I've never used a pump, but always let a self-inflating pad try to inflate itself then take shallows breaths to inflate it fully. For non-self-inflating pads I just blow and don't worry about it as it's much less "stuff" inside that could absorb the water.

Thanks for all these videos, and for demonstrating a rational way to question the accepted wisdom that’s purveyed with such certainty by so many.

@GearSkeptic

5 ай бұрын

Thanks! I appreciate that :)

Great video. I use one of those small pumps anyway. Great for starting the fire but now I won’t worry about inflating it with my mouth. Thanks

Love your videos! My one luxury item is the XLite NXT pump sack that I keep a few things in. Tried using the nyloflume liner on the Xlite but it leaks too much so I'll need to practice some more.

Bel exemple de démarche scientifique! En l'absence de tests exhaustifs, raisonner à partir de connaissances de base de la physique. Bravo!

Great work, thank you

Thanks for filling the science-less consumer gear void as always. An itch that I never knew I needed scratched 😉

GearSkeptic, you're one cool dude. Thanks for sharing your research with us fellow hikers. You're videos are dense with facts and fact checking among other things. We've seen what you UL foods you bring out on a long hike but havent seen your personal hiking gear list. Could you create a video on that with your humor, lol? I'm sure I'm not the only one interested in seeing this.

My pad appeared to have mold inside. I cut it open. No mold at all! Deterioration of reflective film. since then i have suffered from hearing the claims of mold but knowing the truth. This video has lifted that burden. I thank you, my autism thanks you.

@knifejames8163

5 ай бұрын

I'm concerned with the durability of these reflective films in these expensive pads. The pad i cut open was from 2016. I wonder if other instances of pads having foil degradation/exfoiliation are from the same time period. Have they improved? the newer pads are quieter. does this make them more or less prone to exfoiliation? Can anyone find any pictures of other cut open pads?

What an awesome, thorough analysis, thank you! This is real quality content. Personally I carry and use the pump sack with my nemo tensor. It's 2oz and packs down to nothing so I'm always surprised that carrying pump sacks can be so controversial. Yes, I'll admit one of the reasons I've used it is the mold growth thing, but a big reason is also that it's just much easier. At the end of a long day of hiking, huffing and puffing into the valve in a contorted position in my tent is absolute misery for my lungs and back. Even if we say the whole humidity thing is debunked I'm 100% still going to be bringing my pump sack.

@GearSkeptic

5 ай бұрын

Indeed! As far as luxury items goes, a pump has got to be one of the smallest!

Another home run !!! In recent times I feel like I am bombarded from every direction with claims that irratate my common sense intuition......I listen but usually go with my gut....and this is in everything not just gear.....I know I am asking a lot but would GearSkeptic consider expanding and take on the world of ridiculous claims ?......and yes I blow my pad up with my breath. I have used this one for two years and have started smelling the air exhasting from the pad and never get a whiff of mold.....once again vindicated by GearSkeptic....!!!!!!! Thanks a million....!!!!

Thank you for your unrelenting backpacking scientific nerdiness! I’m ditching my nemo vortex inflation bag this year!

On weather forecasts, some show “temperature”, and “Feels Like”. You might find a chart there that gets you a bit closer to what you seek? Courtesy of Half Vast Flying

And here i am shouting at my screen: "But how about in freezing temperatures?!". The myth that i've heard is that moisture freezes during night and therefore ice accumulates in the pad. If i interpret this correclty this shouldn't be huge problem considering amount of water getting in to the pad. Although i am pretty sure not as much moisture exits during deflation, since bigger part of it should be condensed at cold side of the pad.

@briantalbert

5 ай бұрын

Putting even aside the incredibly minuscule amounts of water captured in the pad, what is the contributing factor you are thinking the water in ice form would be having?

@GearSkeptic

5 ай бұрын

I suppose if it's cold enough, condensation at the time of inflation could freeze. But, it would have to stay frozen despite laying your warm body on it all night. If it managed to do that, and be frozen still at the time of deflation, it's possible it could accumulate more the next time you inflate-and-freeze again. No idea how cold it would have to be for that to occur repeatedly. On the other side, frozen condensation would no longer be able to circulate within the pad during any motion-induced convection. That would prevent it from acting like a heat pump, carrying that warmth down to the cold side. I couldn't tell you how these two effects would balance out. Baffle designs within pads make them highly individual.

@tekaistu5472

5 ай бұрын

@@GearSkeptic Snow surface temperature can go far below freezing. However close to ground it might be just few degrees below freezing at least with substantial amount of snow. And i guess ice would be yet another story. With self-inflating pad at -10°C (14°F) i had snow turned in to kind of icy snow during night, so i think inside the pad at cold side temperature would have been above freezing. My pad was no sufficient for those temperatures and i think better pad should have cold side temperature about same as snow has. Maybe there wouldn't be problems with airpad but self-inflating could have some. Probably both types of pads would hold their R-value pretty well. I think the myth that i have heard is somewhat based on fear of damp clothes during winter time and ice accumulating inside insulated clothes. Thank you for great and analytic videos!

@GearSkeptic

5 ай бұрын

Interesting! Good info. Thanks!

Thank you! Interesting discussion, as you say it’s complicated. For moist air, I suspect that convection will be the dominant heat transfer mechanism rather than conductivity. The risk is that a matt filled with moist air will act as a heat pipe, this is an efficient method of transferring heat which is used within some mobile phones and even satellites. A heat pipe increases the rate of heat transfer through a vapour that condenses on one colder surface and evaporates off a warmer surface within a cycle. A pad containing moist air could work like this, the warm top surface will drive warm water vapour to the colder bottom surface where it condenses, transferring more heat due to the latent heat within the fluid. Baffles etc will reduce and its difficult to model. Its difficult to analyse, even with computational fluid dynamics and heat transfer software. Best way would be to do a comparative test, like you have attempted, perhaps with a wider heating pad to reduce the edge effects and directly measuring the temperature under the pad during the test rather than with a heat gun. An alternative would be to measure the temperature on the top surface directly under the heat pad, perhaps beneath a cloth to simulate some clothes, both heat pads and mats would have to be identical, ideally two pads (one dry air, the other breath) tested together at the same time. It would be important to ensure that the two set ups are completely identical and this could be checked before the test by first running the pads and temperature measurement in identical conditions and checking that the temperature beneath the two pads is identical-ideally something realistic like 36 degrees, with a cooler floor temp eg like 5 degrees. Any difference between a breath inflated and a dry air inflated pad would be due to the moisture, if no difference then impact is not significant. This would be very interesting and measuring on the top surface would be more realistic. I am in the blow it up with my breath camp, I suspect that if the increased heat loss is not negligible, choosing a higher R value pad would still be lighter than carrying an electric pump. Wonder if thermarest has tested. Since they now sell an electric pump, maybe they have an interest. I remember that previously their product guidance indicated that it was fine to blow up by mouth. Great channel!

@GearSkeptic

5 ай бұрын

I suspect the difficulties in testing motion-induced convection are what keep manufacturers from doing it. If one brand could make an ad bragging their pad was 2x better in real world conditions...I bet they would!

@peterc5167

5 ай бұрын

Yes, any motion induced convection is another factor, particularly for circulation between baffled volumes, but once the air gap is more than around 12mm (eg a typical double glazing air gap) thermal convection becomes more significant and increasingly dominant compared to conductivity. Spiked my interest to do a more of a real world test which compared the difference between moist vs dry air. Think I could use a hot water bottle in place of a heat pad and a wide chiller plate cooled in the freezer to simulate the ground, an aquarium temperature sensor, plus a sleeping bag over the top and graph the temp change over time for both inflation methods. Can’t do immediately, but will post result here. Great that your channel raises these questions to cut through marketing BS. @@GearSkeptic

You're a hero

This video saves me the money and the grams of carrying a pump or pumpsack! Great content! Thank you!

Quality content

Man I'd love to see you tackle "don't hide in your sleeping bag you'll add condensation which will make you cold", I've heard that recited over and over

@GearSkeptic

5 ай бұрын

Hmm. Hard to test that one. If it gets cold enough inside your tent, it is possible for the dewpoint to be reached inside your sleeping bag. Then, body moisture (and breath) can condense on the filling itself. Mountaineers will sometimes use a VBL (Vapor Barrier Layer) inside their bag. It prevents your humidity from getting caught in the sleeping bag. A really cheap way to go would be to just put one of the mylar space bivy bags inside. But, this is only if it is so incredibly cold as to be a potential problem.

Good video 😁

Love the thoughtful video, thanks. I think the only issue around using "breath" to inflate a sleeping pad is the fact your breath is likely to be warmer than the outside air. This will cause the "breath" -air to cool and condense. Gasses (e.g., breath-air) take up less space as they cool (air condensed as it cools) so we will have slightly reduced R-value as the cooler matt is thinner than it was when you blew it up. This matches all my experience as well. I blow it up when I unpack and set up, only to find it needs a few more breaths before I go to bed.

@GearSkeptic

5 ай бұрын

Same here. A quick puff before bed and all is good.

Gear skeptic, you are the greatest. Thank you. I would love to see a video breaking down the best method of air mattress repair. I saw a method using hot glue that looked pretty promising. Thanks again!

Thank you! I’d always wondered about this, and now can stop feeling bad about blowing up my synthetic exped!

I've got a pump, I figured the tiny bit of weight with what I'm already packing is basically insignificant and the extra function of a light inside a tent (reducing headlight battery usage for outside the tent) was a decent enough trade off. Add onto that the plus of being able to get stuff set up and have the pump start inflating a pad while I set other stuff up is a nice time saver that does add up, also easier to chat with people you're with while setting up when your mouth isn't blocked by a pads mouthpiece lol. Whether I carry it though is based on the trip, I find it to be an option thats nice to have but not necessary.

@GearSkeptic

5 ай бұрын

one of the lightest luxury items you can carry!

Great video as expected. Frozen inflation valve issue. I have observed issues with people orally inflating a self inflating pad to speed things along or make it firmer. Luckily not me as I used the inflation bag. The issues occured in cold weather with some folks being too "wet" when the blew in. I don't think it was humid air but more saliva introduced directly into the valve which subsequently froze and would not open to deflate. So in cold weather if "helping" a self inflated pad either be careful not to wet kiss/use tongue to plug the valve while drawing breath or use inflation bag or pump.

@GearSkeptic

5 ай бұрын

Duly noted!

the logic I've always heard is that our breath starts out warmer than ambient air, when it cools down the pressure drops and makes the pad feel less inflated. so ambient air can in theory keep a pad more firmly inflated. glad to know mold and insulation are a non-issue without a pump

@GearSkeptic

5 ай бұрын

I find that one extra puff at bedtime makes it comfy.

Nice job, very informative and entertaining. I was thinking about the report you discussed on the conductivity of dry air and moist air with moist air being a better insulator. I bet it is because moist air is less dense than dry air. Ask any pilot about lift in moist air and it is less. Dry air is 80% N2, about 20% O2 with small percentages of other stuff. N2 has a GMM of 18, so 36, O2 16, so 32. Displace them with water vapor H2O, with a GMM of 2+16=18 and you can see it will be less dense. Less dense means lower thermal conductivity.

Lol, loved the new message

I still appreciate my pump sack, even if it's just to avoid getting winded when trying to set up camp. 😁 Thanks for yet another great video!

@GearSkeptic

5 ай бұрын

One of the lightest luxury items you can carry!