Are Fire Reflectors really useless?

[@FelixImmler]

Next Friday i show you how to build a fantastic organizer/shelf. I hope you tuning in again.

[@davidjacobs828]

Excellent and very informative video Felix.much appreciated sir.

[@robertbarnes2598]

I think you should of done the temps in reverse. 1st with the reflector and wall. 2nd without the wall, and 3rd without the reflector.

[@TwistedSither]

Your conclusion makes a lot of sense. The reflector may not function quite like a mirror for thermal energy, but it definitely affects airflow around the fireplace so that more heat may flow in your direction. Also, any object placed near a fire will absorb a certain amount of heat and then gradually release it back into the surrounding environment. In my experience, space blankets work quite well.

[@FelixImmler]

Thanks a lot for your interesting comment!!!!

[@foxbashed424]

I agree with you in 💯% .

[@frikkiesmit327]

Well it must work cause how would it aid in survival? Mean in the old days people didnt have the luxuries we have.

[@frikkiesmit327]

Its kinda like a hot car engine. The hot air is trapped by the engine hood and by some panels at the bottom. Dirven a car engine hot so that the radiator electric fan turns on and even whem car is switched off. Open the hood and just feel how long you feel that heat coming out. I would say its almost the same with the fire reflectors. Almost trapping heat.

[@mlinaje]

@@FelixImmler time to test with survival blankets ;-) Nice video as aaaaaaalways :-) Thanks Felix!

[@TheScoundrel70]

Hi Felix, I agree with your conclusions from my own experience. For what it's worth, when I was shown the wood wall behind the fire, I was told it was to draw the smoke away from you, towards the wall because it restricted the airflow to the fire from that direction, making a lower pressure area which drew the smoke in that direction more than any other. This is why when you have an open fire and get close to it, smoke can seem to chase you around, no matter what side of the fire you move to since you are creating the barrier and low pressure area. This of course does not allow for the effects of wind, but I do believe the theory is valid. Thank you for a great episode of Professor Immler's Wilderness Labs!

[@FelixImmler]

Thanks a lot for your super interesting comment!

[@raffrix993]

The Warm Stone heats Up the Air and creates a chimney-like effect. The Warm Air rises and "Pulls" fresh Air from you to the fire...so the smoke is less likely to hit you

[@nerdexproject]

As long as a surface reflects visual light it can most likely also reflect heat as heat is just another type of electromagnetic wave (just like light). But in addition stone can also store heat and re-emit it over time which makes it even more useful. So yeah, reflectors are for many reasons a good idea! Very interesting video!

[@FelixImmler]

This is the 100 Point comment!

[@asconajuenger]

Dein neues Intro ist ja geil! So viele alte coole Videos dazu verwendet! Spitze, wie ein Zeitsprung!

[@FelixImmler]

Danke, dein Feedback freut mich!

[@nauticalknotcraft]

For me, it's worth the work for the extra heat. A well done experiment Felix. Thanks for sharing your knowledge.

[@josercarlucci]

Excelent Felix, thank you for share!

[@nickblanchard1629]

Great job. I keep a emergency blanket at all times in my EDC. It traps 90 % of body heat. I used a plow point set up and a winnerwell stove. In 28 % F setting. It kept me warm enough throughout the night. Thank Felix. Cajun Nick

[@FelixImmler]

hello Nick. Thanks a lot for your interesting hint!

[@Taromovies]

Great to see the resolut after our discussion, sure for an perfect measure the wind, the outside temperature and the size of the campfire should be exactly the same, but you got very close to it, thanks for the effort and the very good and understandable pictograms, regards Taro

[@FelixImmler]

Thank you so much my friend. And thank you also for your fantastic support. I can ask you everything..that's great!

[@HAYAOLEONE]

I would have done things in reverse. Get a good stable fire going and measure with both, in no wind. Then remove one and measure a minute after, in no wind. Then remove the second and measure a minute after and 5 minutes after, in no wind. The fire intensity is the biggest variable of the small experiment.. Plus, contact thermometers might have worked better. But hey, good video still. And we all know from experience solid 'screens' have many advantages.

[@matmin6221]

Nice work & great finding.. Thanks for your effort to make this video.. Keep it up..

[@mbarr1029]

Very well shown and explained. Thank you Felix

[@TheRangaTanGaming]

Here’s the problem I have with these criticisms: this entire concept of reflectors would not have survived for practical purposes, as it would have been wasted energy and effort. A commodity that was valuable for those in the wilderness. There had to be some kind of value for people to have decided ‘I’m going to spend an extra hour or two on making this little wall in front of the fire so I can be warmer’ more than ‘I think it makes me feel warmer… maybe?’ Great video as always, Felix.

[@gkrstini]

you make things with what you have around you, it is not harmful to know something, same thing is why in desert you dont build wooden house, and in forest you dont build rock house

[@Olyphoto7]

Bravo Felix! I can’t imagine anyone saying that reflectors don’t work, now you prove them wrong.

[@FelixImmler]

Thanks a lot Dan!

[@davidbenner2289]

Oh Great One, Mr. Immler, good class. I'm have around fires from all over the World and from sea level to high altitude places. Since a very young age to my late 60's, which is now. I was a wildland firefighter, some call forest firefightrer, for a time, and spent decades as a urban, metropolitan, all hazards structural firefighter. Since my teaching credentials are current I can say I have been a firefighter for over 42 years. Your testing the methods was good. The radiant heat can get so hot that it can burn you. Thermal radiation. Rare conditions most will seldom see. I was also a Cub Scout, Boy Scout, Explore Scout, Senior Scout and Assistant Scout Master in Japan, Thailand, German, the United States and in other countries with other Scouts. And the several meters high lumber and fallen tree fires on my farm were spectacular! In a below freezing camping situation the reflectors will keep you warm. Good class. See the difference with a lighter surface with a darker surface. Same as light, the lighter surface will reflect more. Like starting a fire, the darker surface absorbs more, starting the fire easier. My children and I used to camp in the snow next to our farmhouse to learn how to live in the freezing conditions in the Highlands of West Virginia. You need to get with Victorinox to sell your classes along with their knives, saws and axes. I should write to the Swiss Government to start a Ministry of Common Sense and have Felix Immler as the appointed life time Minister of Common Sense!

[@BCVS777]

Too simplistic I know but any barrier (around or above the fire) that reduces heat being moved away from us is beneficial. We work on reflectors because we can but the fact remains that most of the heat escapes straight up and this is much harder to capture from an open fire. Great video! Thanks!

[@HAYAOLEONE]

Small/medium filled up metallic water containers kept right above even a small fire will accumulate heat and can be placed inside clothing or under your butt.

[@Waldhandwerk]

Tolles Video und gut aufgeschlüsselt lieber Felix! Ich mag reflektions Flächen. Schönes Wochenende dir und euch Sepp

[@FelixImmler]

Danke für deine tollen Input zu diesem Video! Das hat mir sehr geholfen...

[@gordonwedman3179]

I am quite sure both of these additions will help you stay warmer. At sunset walk past a brick or stone wall that has been in the sun all day. You will feel the heat being radiated by the wall. Rocks behind the fire will do the same. This isn't reflection though, its absorption and re-radiation. There might be some reflection as well. I think the shelter reduces airflow and allows the fire to heat the surroundings more effectively.

[@magicdrshoon]

So pleased you have done this! I had the same thoughts! I respect the others who say these don't reflect the heat - they might not (I think they do) - but that's irrelevant. The purpose is to make camp warmer. However they work (wind reduction, reflection etc) - they work! Love your channel! Keep it up!

[@stephan123321]

Moin Felix, klasse Versuchsaufbau! Finde dein Ergebnis absolut sinnvoll und nachvollziehbar. Zwar habe ich nicht soviel Erfahrung, aber wann immer ich mal ähnliche Voraussetzungen hatte, war das Feuer, gepaart mit einer (oder mehreren) "schützenden Wand", von größerer Wärme....bzw. man fühlte sich dann immer geschützter und geborgener. Wünsche dir ein entspanntes Wochenende, Amigo....Peace, Stephan :-)

[@FelixImmler]

Hey Stephan. So schön von Dir einen Kommentar zu lesen! Liebe Grüsse in den tiefen Norden Deutschlands!

[@stephan123321]

@@FelixImmler Danke dir mein Freund. 🙂 So nach wie vor regelmäßig bei dir rein.....schaffe es nur leider nimmer, immer einen Kommentar da zu lassen....werde aber versuchen, das wieder zu verbessern. 🙂 Übrigens....wohne nicht mehr am Meer, sondern seit letzten Sommer in Leipzig.....wenn es dich also mal dahin verschlägt, dann melde dich! 🙂 LG Stephan

[@k.1873]

This channel is the kind of thing KZbin does best. We don’t need more mass media selling us hype and distraction.

[@andytorre4858]

I’ve learned so much from your channel Sir. Cheers from Texas!

[@FelixImmler]

Thank you Andi!

[@cee8mee]

The idea that some materials 'reflect' better than others is solid, however, that doesn't mean useless. Also, rather than reflecting behind you, more likely the warm air is stilled and trapped, rather than reflected. Either way, the more contained you are, the more warmth you trap, so any time you surround yourself and the fire, to some degree you will be warmer.

[@ahayseed654]

Ditto☺

[@oldbatwit5102]

Yep.

[@szakmanygyorgy]

Man, you are a genius! So much about the wisdom of the "great bushcrafters" on KZbin. Big thanks for this simple, but very convincing video! Best wishes from Hungary!

[@chriskodani2543]

Felix, that's a very clever experiment! Thank you for sharing it with us! If I could suggest one further step: try this again adding a space blanket to your wooden shelter. I would guess that the shiny reflective surface should result in an increased temperature on your back. Such a test would be very relevant, because many people carry space blankets as a small, light weight, inexpensive piece of survival equipment.

[@FelixImmler]

Hello Chris. You are right!

[@Swedwoods]

very interesting. I wonder though.. the second fire with the reflector, a fire had been burning on the spot for a much longer time. (Since it was dark, so at least one hour in between) The coal bed should be deeper and the ground under and around the fire is much more heated, thus radiating more heat on you. I would have wanted to see if anything happened if someone would kick down that reflector wall and immediately see if there was a difference on your chest. Thanks Felix for great videos!

[@acawap]

I saw what I think was the same video you referred to, and am glad you did this video, because I trust your real-world opinion more than the scientist. I think the scientist was caught up on semantics, that "fire reflectors" aren't actually "reflecting" but they do work. Got thinking you could have saved some time with your tests by simply sitting on different sides of the fire, though.

[@1life2risk]

The so called "fire reflectors" are not working as reflectors in a physical way because there is no mirroring surface to reflect. They work more as re-emittors. So far science can be trusted.

[@FelixImmler]

But as much i know infrared waves don't only reflect on a mirrow...

[@1life2risk]

@@FelixImmler Correct. But: most of mineralic or organic materials (as wood or rocks etc.) absorb oder emit over 90 % of the incomming IR (= longwave) radiation, that means that the maximum of reflexion is less than 10 %. The so called fire reflectors will reflect a very small amount of IR radiation from the fire. If they are heatet up enough by the fire, they will start to emmit radiation themselves. But that's not reflection, it's emmission by radiation.

[@markgilmour5757]

I would agree, with my experience, when you use large, flat stones as a base to the fire, the fire is very hot. Maybe the stones heat up and radiate more heat, but more heat is more heat. So less wasted energy. Love your video👍

[@FelixImmler]

Hello Mark. Thanks a lot for your feedback!

[@patrickwahl6321]

Danke Felix für den informativen Test 👉👍👈

[@FelixImmler]

Sehr gerne 👍

[@james_lessick892]

I agree, reflectors really do work. Thank you for the data to prove it. See you next week. 👌😎👍

[@FelixImmler]

Thanks a lot James!

[@jimcy1318]

Which fool said they didn't work, of course they do. But at least you showed them reasonably scientifically. 👍 Good video, and I'm enjoying this series.🇬🇧🇩🇪

[@bruc33ef]

Lonnie at far north bushcraft and survival.

[@FelixImmler]

Thank you..

[@FelixImmler]

But he said also that a reflector in the back is useful...

[@FelixImmler]

That's true but i wanted to build a shelter anyway😊...

[@mathewlawton8944]

Thank you 4 the video and possible life saving tip

[@FelixImmler]

Thanks a lot for watching!!

[@clintonroushff7068]

If it isn't too much trouble building an enclosure will add to your experience. Thanks for sharing this with us. Take care Felix

[@dirtmcgirt6769]

Great video. Love the visual temperature readings and graphic. Looks like very fun work and testing!

[@FelixImmler]

This was really interesting for me...yes!

[@sorinoutdoors5418]

Your results make sense, great job in conducting this experiment Felix.

[@FelixImmler]

Thanks a lot!

[@krazmokramer]

Welcome back Felix! I hope you had a pleasant time off from KZbin. Interesting video. I'm not sure the technicalities of the science are important here. The point is, if you are camping, surrounding the back of your campfire with tall stones and making a wind break behind you will make you feel warmer. That's the big picture. As they say, you can't see the forest through the trees. Thank you for making this video. That took a lot of work!

[@anthonybarra2391]

Great follow up video. It's clear if you surround your fire to stop the wind and keep the heat in, you will be warmer.its more to contain the heat rather than reflect it . Looks a perfect camp to me

[@Flashahol]

What both walls are doing is keeping more of the warm air in place (convection), thus resulting in a warmer environment. The rocks may also act as a mass accumulator, but that effect is negligible once you step away from the fire IMO.

[@FelixImmler]

Thanks a lot for your interesting comment!

[@globalfallout7249]

Brilliantly concluded and conducted Felix. I personally find it better the way you built the campsite reflecting wall behind the camp fire and lattice work and foliage behind keeping the back nice and warm. Spruce is good but very flammable. So I prefur to use Heather moss or bracken. Green of corse. Or even better if possible a rock crevice with rocks in front is what I have found best of all. Natural boundaries work best if you can find them.

[@MutsPub]

Good information! Thank you.

[@FelixImmler]

Thanks for watching!

[@dwayneschoon8597]

Thank you Felix. I appreciate your time and effort on this matter. I also enjoy the heck out of your videos. Your humor and your creativity is very much appreciated

[@randy-9842]

Nicely done, Felix. This confirmed my expectations too, so I very much appreciate your efforts and your methodology -- also, your "aesthetic" observations and appreciations seem spot on to me as well.

[@PhilEvansOnline]

I have often used an aluminium wind shield behind a small firebox to heat a tarp shelter. It most definitely has an effect as your video clearly demonstrates. Thanks for sharing. 👍

[@bushcraftbasics2036]

Thank you for making this and confirming what many thought all along. People noticed a difference when the fire and themselves had something to reflect the heat otherwise it would not have stuck around.

[@FelixImmler]

Thanks for your feedback!

[@MrBearbait75]

Thanks for doing the testing to prove what we have been taught and have experienced personally! I'm going to start calling you, the Hulk (carrying the big rocks like it was nothing) ! 😀

[@blueeyeswhitedragon9839]

The addition of an aluminum emergency blanket on the interior wall of the shelter would increase the benefit of the heat reflection. Your presentation is the best that l have seen to date, and backs up common sense experience in the woods. Thank you.

[@ahayseed654]

I agree Felix. It is like a living room. A micro climate, if you will. The stone on one side and the shelter on the other, prevent heat loss by absorbing the heat that would otherwise radiate away. You are basically creating a primitive stove, a somewhat contained environment, that reflects heat. Your "science" seems to show that. Keep up the good work.😊

[@truckerenoch8824]

The updraft of the fire mixed with air swirling around hot rocks in-between reflector/deflector can create a little nano climate that will temper cold breezes. It won't do a lot in strong wind, but I'm still convinced it's still better, no matter what your scenario. Build reflectors/deflectors, no matter what the "science" tells you. You'll get warmer just building it!

[@HAYAOLEONE]

😁 the old 'triple heat' of working on your fire 😆

[@truckerenoch8824]

@@HAYAOLEONE exactly!😆

[@boola69]

Interesting video providing proof of theory. Your videos never fail to amaze me. Kudos from the 🇬🇧.

[@FelixImmler]

Wowww, thank you so much!!

[@boola69]

@@FelixImmler No more than you deserve for your great content.

[@rockytopwrangler2069]

...Put something like a a piece of mylar or emergency blanket on stick or stone face .. reflective qualities .. .. also complete reflector wall taller and without voids.. a means of directing heat directional desired.

[@FelixImmler]

Thanks for your comment!

[@gerhardpeace]

Very informative. Thanks for the information and the hard work.

[@seanfitzgibbon235]

Great video Felix! I’ve always thought I was warmer with a natural shelter and fire with reflector- now there is quantifiable evidence!

[@FelixImmler]

Thank you Sean!

[@WoodyAndy]

Nice to see a practical scientific approach to this rather than people parroting what they've heard on social media. Good for you for busting out and providing real world evidence! Atb, Andy

[@vinnyoutside8936]

I too have seen those video's saying that it doesn't work, but i have camped in some cold weather and I can tell you that it DOES work. Good video Sir!

[@FelixImmler]

Thanks a lot for your interesting feedback!

[@garyhubbartt8351]

Lucky you, Living in Switzerland!!! I would Love to be there in The woods camping Out!!! -GARY. 🇨🇭

[@FelixImmler]

Thank you Gary. But dont forget.. the density of the population in Switzerland is very hight!

[@peterappleton5213]

Well thought out Felix, thanks from South East England

[@FelixImmler]

Thanks a lot Peter!

[@jamesbarisitz4794]

A pocket sized mylar space blanket attached to the rear wall would make a noticeable difference Felix. Hung the width and length of the rear wall and held flat to the wall would be ideal.

[@FelixImmler]

Yes i belive!!

[@mywrkout1]

Your experiment turned out just as I thought it would. A fire reflecter with a shelter wall is definitely warmer, science or not, just good common sense! Thank you Felix for putting this to the test, always enjoy your videos!

[@jacquescoutu7631]

I must be old fashion as well as I completely agree with your opinion and analysis.

[@FelixImmler]

Thanks a lot Jacques!

[@auroraborealisknives4019]

I love the ‘swiss quality’ of this video I also saw the survival russia video and thought that his testing protocol was incomplete Good job 👍

[@FelixImmler]

I will watch his video. normaly lars makes good videos. Thanks for this hint!

[@photoshopman1972]

Thank you for that demonstration. I also like how you did it in stages and used multiple data points. If I failed to mention it in the last video, I really liked how you showed off different things/projects and showed an application of them together. Please keep up the good work!

[@angtarionuretanor6703]

Danke für das Experiment. Ich fand Deine Sheltervariante sehr anregend.

[@FelixImmler]

Danke fürs Feedback!

[@mikecrowley8923]

One of the heat transfer mechanisms from two bodies at different temperatures is radiative heat transfer. This transfer is proportional to the the 4th power of the temperature of the warmer body minus the 4th power of the temperature of the cooler body. In addition, it will depend on the amount of surface area that each body can see of each other. What the reflector and roof of the shelter does is shield you from either a cloudy sky or outer space. You are at 37 C. A cloudy sky is around 0 C and outer space is around -270 C. So you will certainly radiate heat. A "reflector" made of wood, which can reduce the amount of exposure , ie surface area, to the colder environment, will reduce the amount of radiative heat loss. The roof absolutely shields you from the cold of the sky. If the "reflector" warms up from the fire then even better but it will still help even if it doesn't warm up. This is a simplistic model because of thermal gradients from the ground up to outer space but the physics is sound.

[@FelixImmler]

Hello Mike. Woww, this sounds very scientific. Thank you!

[@jenniferbauman4802]

Yep the reflector works. And bigger the fire and bigger the bed of coals the more heat you will get. The taller the reflector the better it works. A mylar space blanket will help a lot. But a super shelter . Would have brought the temperature up to about 70 or 80 degrees. I hope you keep doing camp outs. But whatever you do is great. You are very good in the field and a master of the Swiss army knife. I think you taught Mcgyver. You heard that before. I know. Well God bless. From Glenn CATT in Massachusetts.

[@FelixImmler]

Your comment makes me happy! Thanks a lot.

[@jenniferbauman4802]

@@FelixImmler your welcome. You are great at what you do . God bless. From Glenn CATT in Massachusetts. In U S A.

[@stevemorris3710]

Great video! For sure it had to work to some extent, but I didn't predict it would be so effective. Thanks for answering this question.

[@robertogomez3698]

Nice work. The experimental method you uses is good. Nice work.

[@FelixImmler]

Thanks a lot Roberto!

[@tbk1801]

Very nicely done, if you had added a space blanket, to the shelter wall, it would have run you out… nice job

[@FelixImmler]

Thanks a lot for your kind comment!

[@NordicEdge]

Another well made video and I really like how clearly you show the difference. Well done.

[@FelixImmler]

Thank you so much!

[@PiscatorLager]

They should be called fire-reemittors, as that's what they do, from a technical point of view. Reflection is something different

[@thedamnyankee1]

yes! that's what I was going to say. Its more about reemitting, not "reflecting"

[@1life2risk]

Jepp, Mors Kochanski told it in a similar manner about absorbtion and re-emission. kzbin.info/www/bejne/bIW8f5yDrZ2ng6M&ab_channel=PaulKirtley

[@bobmorton4633]

It is not emitting heat, it is deflecting or reflecting depending on how you want to look at it. In order to be an emitter, you would have to head the objects first. In theory, though, it is actually containing the heat so it is centralized. If he had of put up 2 more walls, it would show that more. Heat actually rises and by doing so, creates a vacuum drawing in the cold air. It also radiates outwards. Putting up walls, reflectors etc, keeps the heat from moving out and pushing it up instead. By doing this, it draws all the colder air and leaves warmer air behind.

[@thedamnyankee1]

@@bobmorton4633 Yes, you ARE heating up the objects - with the fire. that's the point. You heat them, and one of they ways they cool is through IR radiation.

[@bobmorton4633]

@@thedamnyankee1 You are not heating them. You are containing the heat in a given area. To heat them, they would have to be much closer than they are. Over time, the radiant heat will heat them up. So will your body heat. At first though, it contains the heat so it doesn't escape. Basic physics. If it was an emitter, you would need to wait hours for it to heat up. Than if you take it away, any heat that is trapped in it, that is when it would emit the heat. First you contain the heat, then it is reflected back as it builds. As it builds, the radiant heat will warm the object. As the fires dies down or goes out, then you get emitting heat.

[@MichaelR58]

Felix , good video and information , thanks for sharing ,God bless !

[@FelixImmler]

Thanks a lot Michael!

[@miketucker2817]

DANKE DANKE DANKE! Every week I wait for your videos!!!

[@FelixImmler]

Thanke a lot Mike!

[@will.scotnativeingreece]

Hi Felix, great stuff, well presented and an obvious plus benefit. regards Will.

[@FelixImmler]

Thanks a lot Will!

[@tlmoscow]

Superb, Felix. Very well done!

[@FelixImmler]

Thank you!

[@SpaceDave3000]

Most simply put, it traps more heat and keeps it from being blown away in the breeze - and is far from useless. I'm not sure why anyone could think otherwise, it's obvious.

[@snowjoe43]

Very good video Felix! Useful.

[@FelixImmler]

Super! Thank you..

[@mhpupacios]

Excellent demo and really illustrates the point 👏👏

[@FelixImmler]

Thanks a lot!

[@richardanderson6874]

Thank-you for this interesting demonstration. God bless you!

[@thewildernessphilosopher]

I never thought anyone could refute that . It seems common sense, and the same principle of reflecting heat is why space / emergency blankets work.

[@FelixImmler]

Thanks for your comment!

[@richardpearson5036]

Very well researched and presented Felix. I guess your video is proof positive that reflectors really do work. Thank you for all you do buddy.

[@rlgroshans]

There was one more scenario that I was hoping you would have done. Fire without a reflector wall, but with the shelter wall.

[@FelixImmler]

Yes... that's true!! Grrrr....

[@rlgroshans]

@@FelixImmler, even without that scenario, I think you made your point very well.

[@josephramjak4090]

I'd add onto that with a final test with a space blanket behind you, space blanket behind you and above you, behind + left & right side open to funnel heat towards you. Under you possibly? Also using Mors Kochankai's super Shelter method. I know you kind of did that with your geodesic dome shelter v1 and v2. Possibly good test video ideas. Especially combined with the awesome temperature thing-a-ma-bob and the thermal picture. Love your dedication to improving bushcraft & SAK knowledge

[@joemaples6243]

This was great and well done. Thanks. Also, I think the psychological affect of the wall and reflector is a benefit.

[@LJBJams]

Agreed Felix, the effort may not always be worth it, seasonally though, it will be worth the effort (winter)!

[@FelixImmler]

👍

[@raketoped663]

Thank you! I am with you, proofen or not. And at least, the shelter in the back takes away the wind and the cold from behind and above.

[@Veldvaardigheden]

Hey Felix , awesome video !! I don't think that the reflectors reflect heat but they are sure containing the heat of the fire and so it will be warmer . :) So a small shelter and a good "reflector" like one with 3 walls left right and behind the fire makes a big difference in temperature and you create a micro climate like we have in our homes. Thank you Felix !!!

[@paulharding1621]

That’s a great video Felix, simple way of showing what many have believed for a long time.

[@thomasmusso1147]

Good Evening Felix .. 👍 .. I have been looking forward to this Posting since last week and the results are as expected .. thanks for that 😊. Agreed .. any sort of barrier or shelter will retain / enclose heat better than having nothing. 'Reflectors' .. some are more efficient than others .. with in order of efficiency .. from less to more .. Wood, Stone, Aluminium Coatings etc. The Dynamics of Heat Retention and Transfer via Conduction, Convection and Radiation make it a challenge to measure and quantify accurately (unless under laboratory conditions) how effective different setups really are .. and if the time and energy required to do so, in a specific situation, are justified (similar to the energy required to forage for water and food). What would be nice please, is one day perhaps use the Thermal Imaging Equipment on Setups using Tarps (wind and waterproof), 'Space Blankets', Clear Plastic Sheeting (create a 'greenhouse effect'), etc. Using 'Natural Resources' .. in an absolute emergency .. yes. However, technology now allows us to utilise gear such as Tarps, Space Blankets, Plastic Sheeting, etc for more effective, quicker to construct and thus more energy efficient Camp / Emergency Shelters .. in addition to protecting our Natural Resources from unnecessary harvesting. What our Ancestors used in their day was the best technology that they had then .. we now have better. Once again, a good share with much fuel therein for debate 😊. Take care .. Tommy

[@FelixImmler]

Hello Tommy. Thank you so much for your super interesting feedback!!!

[@thomasmusso1147]

@@FelixImmler 👍

[@Aco747lyte]

Another super vlog and I agree with your sentiments which make this video so interesting. I agree that the coal bed should be deeper, too. by the way, as coal is going to become increasingly difficult to obtain because of the 'climate situation'. I strongly suggest you take the opportunity to buy and store as much coal as possible. We've got good stores, too. All the very best ~ Wendi

[@FelixImmler]

Thanks for your hint!

[@Houarnev_Cadranier]

Thank you very much for this experience in live condition. I completely agree with your results and analyze.

[@fizzlebug]

There is generally a little bit of reflectivity on logs and rocks (in particular if the logs are greyish or white, like split green poplars, or if the rocks are glittery from quartz or certain sediments). However, they do not work like described in many survival manuals, where you build a small log wall a long way from a small fire and expect a huge reward. If built close enough to the fire, there can certainly be a bit of bounce-back and reflection. Most of what "bounces back" from a "reflector" though, is absorbed heat which is re-emitted from the logs or rocks, but at a shorter wavelength. It can sure make a noticable difference, but to expect it to work like a mylar blanket and heat your shelter immensly (as the common bushcraft myth goes) is not true. For anything to have such a reflective capacity, it needs to be essentially a mirror polish, like still water, mylar, aluminium foil and to a lesser degree snow. The light test that you showed is excellent. The more something reflects back light, the better of a fire reflector it is, since the emission of light and emission of heat are quite related.

[@mendoeta]

Very good explanation grand master!!

[@FelixImmler]

Thanks a lot!!

[@stacyhazelwood4033]

Nice video, Felix. I have heard arguments both ways. But, I agree with your assessment.

[@tomballard4794]

Have you ever tried a lean to in front of you and one you sleep under ,with a fire in between both? The sleep shelter would be higher than the fire lean to and hang over . The space between the two lean to's would act like a chimney. I have seen one other site do this with a poncho and a Emergency blanket but no explanation on how or why to do it that way.

[@FelixImmler]

Thanks a lot for your interesting comment!

[@chiefkirk]

Great job my friend.

[@FelixImmler]

Thank you so much dear Chiefkirk!

[@dajak11]

very nice test, but for me without a surprising outcome. reflectors work, thats why there is a name for it, reflector. also the reflection of light on your face is very educational. To reduce variables you should not do the last measurement 10 minutes after thatching the roof because you generate bodyheat which disipates from you back to ofcoarse. there are numerous varaibles I know but you have proven the point.

[@FelixImmler]

Thanks a lot for your interesting comment!

[@tomasthomas7407]

Great Start! for creating more warmth ‘capture’ from a given fire. With a back reflector, the difference from 55F to 66F would being ‘cold’ or ‘comfortable’. imho. Definitely, i am going to look into this question more. Maybe light weight aluminum fire panels, and mylar back reflector materials. Good 👍🏻👍🏻🔥🔥🔥👍🏻👍🏻 job

[@giuseppeiaria6564]

Thanks for the Video Felix. You're always great in providing physical evidences and sharing your skills. 👍🏻

[@FelixImmler]

Thanks a lot Seppi! :-D

[@chriskodani2543]

One experiment like this is more valuable than hours of people arguing! Hurray for Felix the Scientist! He's like a MacGyver for the 21st century!

[@stephanygates6491]

Beautifully executed empirical experiment! I do think, however, the difference with the barrier behind you is due to the warm air collected between your back and the wall.

[@FelixImmler]

Thanks a lot for your feedback!

[@georg0444]

This is the way. (in 7 min.) You get about 3 degrees Front and Back for half a day of work. Take it or leave it. Finally I can Quit watching Videos about this . Thanks Felix

[@FelixImmler]

Haaa ha haa this is the 100 point comment!

[@eliot1970]

Thanks Felix. I always learn something from your videos.

[@FelixImmler]

I am happy to hear that!

[@richardsolomon8076]

Nice job Felix 👏 warmer is WARMER 👍. I got a new felling axe 🪓 and sharpened it with your file and flannel method, then finished with a wet stone 👍🏻very happy with it 😀

[@juliomarin83]

I liked your demonstration! In my family we use the same principle when doing barbecues. By placing a piece of cardboard over the meat it is possible to use the heat a little bit more efficiently

[@FelixImmler]

Thanks a lot for this interesting tip!

[@opotime]

I guess WE Seen the Same Videos and im full on your Side... IT works but they are so focused on the Used words... Like the Talks about a honing rod isnt sharpening the Blade, but the Blade Cuts better after using IT. :-)) I tryed to explain that in the comments but now i can just Show your Video, thx for making my Life easyer. Greatz from Germany And have a nice Day opo