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.
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.
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!
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!
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.
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.
I absolutely love all the actual measurements token thru-out this whole process and absolutely loved this whole video! In really bad conditions every little bit of heat is needed! So you really illustrated it perfect in this one Mr.Felix! Two thumbs way up! 👍🏼👍🏼😁keep them coming my friend! Cheers, Jerbs 👍🏼🔥🔪🇨🇦
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
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👍
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.
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!
Joo man, great experiment! You made a great re-emitter there from stone, close to the fire! But I would be wondering what the effect of a wooden re-emitter would be, as the material wood, can't be placed so close to the fire and seems to have less readmitting properties than stone. I would expect that a wooden re-emitter wall has no significant effect on the temperature. Maybe a nice second chapter to this experiment series, for a video!?? Great watching you, as always!!
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.
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.
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.
...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.
Servus Felix, denke die Reflektoren machen wirklich Sinn, wie von euch sehr anschaulich getestet. Es geht halt bei einer eingehausten Lagersituation nicht soviel Wärme flöten, der Wärmetausch mit der Umgebung ist etwas langsamer. Auf jeden Fall ein schöner test/Video. Grüße aus dem Spessart
Interesting. Now I know why you built your shelter after doing the fire. Maybe the science still did not proved it, but yes the experience of generations of outdoors men did. Never underestimate intuition and experience, science it is not the only way to get knowledge. Ciao, alla prossima!.
Hallo Felix! Für den Anfang ein sehr guter Test! Es gab insgesamt 2^2=4 Testfälle: fehlt (kein Reflektor / Feuer / Shelter). Wäre es filmtechnisch nicht besser gewesen, die Messreihen rückwärts durchzuführen, so dass man dass große Shelter nur hätte einmal abreißen müssen? Des weiteren hätte mich eine Messung interessiert, bei der die Reflektor-Wände (evtl. bis zu 3 (c-Form)) stehen und dann schnell entfernt werden (siehe Kommentar Swedwoods). Dazu bräuchte man dann aber kleine Reflektor-Wände nach Bauzaun-Prinzip. Auch interessant wären Messungen zu einem Sibirischen Feuer bei der das Feuer an sich schon der Reflektor ist. Vielen lieben Dank für deine gute Arbeit und deine tollen Videos. Einen schönen Sonntag wünscht Sven
The thing that seems to make sense is that your structures create a pocket for the heat. I realize this is not a revelation to anyone. LOL! As usual, nice video, thanks!
Hey Felix, good video, I knew what you did would work, but my question is about the smoke. I have read again and again that if you have a mass behind the fire that the smoke would go straight up. I have never found it to be true. I would love a video on this.
Und ich dachte im letzten Video, das du dich vielleicht zu spät entschlossen hast zu bauen, da es schon dunkel war, als du dein Dach gedacht hast. Jetzt wissen wir das du hier wichtige Experimente durchgeführt hast! 😜
Ich nutze als Reflektor eine Notfalldecke, allerdings Silber und Olivgrün, nicht Gold. Ein kleiner Schlitz zwischen Shelter und Notfalldecke reicht um den Rauch abziehen zu lassen. Zusätzlich ist das Feuer so kaum sichtbar für andere
Hallo Felix Das es wärmer wird, hat mit Konvektion und nicht mit Reflektion zu tun. Das ist ein Unterschied. Bei Reflektion spricht man von der zurück geworfenen Infrarotstrahlung. Bei Konvektion handelt es sich um bewegte Luft.
enough reflectors, behind, each side, in front and on top ends up being a shelter. Ever wall or covering has got to increase and trap the heat from a fire. 🤣👍✌🥃
Very well done, a good experiment and analysis of the heat radiation. I think that a lot of the confusion is mostly related to the word “reflector” In most cases it’s radiator, wind barrier, depending on the materials. Is it useful? I would say yes for reasons other than reflecting. Accumulating and slow releasing of heat, shelter, more light and protection and a wall behind a person will offer more insulation and capture the heat better with less wind to influence the temperature but mostly I find that the biggest benefit is the placebo effect it has on us. Good video 💪
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!
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
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!
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
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.
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.
@@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.
@@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.
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.
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
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.
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 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
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) ! 😀
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
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
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.
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 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.
This does not prove reflection of heat, it demonstrates that you are creating a micro climate of still air where heat can build up and dissipates slower, but whatever you call them a wall behind your fire and one behind you will keep you warmer than not having them
Great Video 👍Have you ever tried building reflectors out of woodlogs instead of stones? Always wondered if a woodenlog reflector is still working despite the small gaps in between the stacked logs. Gruess us Lachen ✌
One advantage of the dry wood screen/planks close to the fire is that one can lean directly against them if on the other side the fire is controlled by another disciplined camper.
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.
Hey Felix. Interessante Betrachtung. Allein wegen des zusätzlichen Windschutz auf der Rückseite ist das absolut sinnvoll. Hab am WE extrem gemerkt wie ich am Rücken im Nierenbereich ausgekühlt bin weil ständig der Wind dagegen geblasen hat. Beste Grüße, Matthias
Almost all materials have some reflectivity in the thermal (5-13 micron wavelengths). Flat surfaces reflect better. Most (non-anodized) metals are very reflective, approaching 100%. Non-metals are also somewhat emissive, and for emissitivity, "flat" is not important.
Felix - I like it - but If you put a Mylar rescue blanket in front of the branches above you and in front of the rocks, you will get 80% of the infrared rays reflected. I hope I haven't told you any secrets now ;-)) pls. go ahead ...
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!
Spot on Felix. I don’t know who thought otherwise but it wasn’t correct. The wall and reflector containing the heated environment is obvious. That’s the whole idea isn’t it?.
Hi Felix, Very interesting stuff😊... To me you are bound to capturing some reflected heat on the inside of the Shelter you have proved. I wonder if the stone reflector was positioned in a "tight" U shape with the open end towards the shelter if It would increase the reflected heat even more. many thanks for sharing and hope you understand my point. Cheers Ian
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
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.🇬🇧🇩🇪
Seems like some lazy bushcrafters came up with the idea that building these reflectors was too much effort and tried rationalize their decision by playing the science card. Thank you Felix for actually using the scientific method. Btw, a flimsy space blanket against your inside shelter wall would have been a great 4th data point. And then the icing on the cake would have been to toss a plastic drop cloth over the shelter a’la mors kochanski for the 5th and final data point.
Thank goodness you understand the difference between radiant and convective heat!!! Lonnie was dead wrong and you proved it. His mistake was to measure air temperature which is grossly incorrect.
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.
Did you try with an emergency silver blanket behind you at all? You can also put foil around the fire reflection wall. I think this increases the temperature more as more natural materials will absorb the light and heat.
Next Friday i show you how to build a fantastic organizer/shelf. I hope you tuning in again.
Excellent and very informative video Felix.much appreciated sir.
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.
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.
Thanks a lot for your interesting comment!!!!
I agree with you in 💯% .
Well it must work cause how would it aid in survival? Mean in the old days people didnt have the luxuries we have.
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.
@@FelixImmler time to test with survival blankets ;-)
Nice video as aaaaaaalways :-)
Thanks Felix!
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!
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!
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.
Ditto☺
Yep.
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.
Hello Chris. You are right!
Tolles Video und gut aufgeschlüsselt lieber Felix! Ich mag reflektions Flächen. Schönes Wochenende dir und euch Sepp
Danke für deine tollen Input zu diesem Video! Das hat mir sehr geholfen...
I absolutely love all the actual measurements token thru-out this whole process and absolutely loved this whole video! In really bad conditions every little bit of heat is needed! So you really illustrated it perfect in this one Mr.Felix! Two thumbs way up! 👍🏼👍🏼😁keep them coming my friend! Cheers, Jerbs 👍🏼🔥🔪🇨🇦
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
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👍
Hello Mark. Thanks a lot for your feedback!
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.
Yes i belive!!
Well thought out Felix, thanks from South East England
Thanks a lot Peter!
Excellent demo and really illustrates the point 👏👏
Thanks a lot!
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!
Joo man, great experiment! You made a great re-emitter there from stone, close to the fire! But I would be wondering what the effect of a wooden re-emitter would be, as the material wood, can't be placed so close to the fire and seems to have less readmitting properties than stone. I would expect that a wooden re-emitter wall has no significant effect on the temperature. Maybe a nice second chapter to this experiment series, for a video!?? Great watching you, as always!!
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.
Hello Mike. Woww, this sounds very scientific. Thank you!
Just build it - you’ll see.
Thank‘s Felix👍🇨🇭
Thanks for your comment!
Thank-you for this interesting demonstration. God bless you!
Very informative. Thanks for the information and the hard work.
This was great and well done. Thanks.
Also, I think the psychological affect of the wall and reflector is a benefit.
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.
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.
Good information!
Thank you.
Thanks for watching!
Very helpful. Thank you.
Thanks for watching!
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.
Thanks a lot for your interesting comment!
...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.
Thanks for your comment!
Thank you!
This was short and to the point proof of concept.
Servus Felix, denke die Reflektoren machen wirklich Sinn, wie von euch sehr anschaulich getestet.
Es geht halt bei einer eingehausten Lagersituation nicht soviel Wärme flöten, der Wärmetausch mit der Umgebung ist etwas langsamer.
Auf jeden Fall ein schöner test/Video.
Grüße aus dem Spessart
Reflectors on a nice cold night is worth the work. Awesome video my friend
Interesting. Now I know why you built your shelter after doing the fire. Maybe the science still did not proved it, but yes the experience of generations of outdoors men did. Never underestimate intuition and experience, science it is not the only way to get knowledge.
Ciao, alla prossima!.
Grazie Lenorado!
Animals know... They always try to 'nest' to keep warm/less cold.
Hallo Felix!
Für den Anfang ein sehr guter Test! Es gab insgesamt 2^2=4 Testfälle: fehlt (kein Reflektor / Feuer / Shelter). Wäre es filmtechnisch nicht besser gewesen, die Messreihen rückwärts durchzuführen, so dass man dass große Shelter nur hätte einmal abreißen müssen? Des weiteren hätte mich eine Messung interessiert, bei der die Reflektor-Wände (evtl. bis zu 3 (c-Form)) stehen und dann schnell entfernt werden (siehe Kommentar Swedwoods). Dazu bräuchte man dann aber kleine Reflektor-Wände nach Bauzaun-Prinzip.
Auch interessant wären Messungen zu einem Sibirischen Feuer bei der das Feuer an sich schon der Reflektor ist.
Vielen lieben Dank für deine gute Arbeit und deine tollen Videos.
Einen schönen Sonntag wünscht Sven
The thing that seems to make sense is that your structures create a pocket for the heat. I realize this is not a revelation to anyone. LOL! As usual, nice video, thanks!
Great experiment, Felix
Hey Felix, good video, I knew what you did would work, but my question is about the smoke. I have read again and again that if you have a mass behind the fire that the smoke would go straight up. I have never found it to be true. I would love a video on this.
Thanks for your inspiration!
Hi Felix thank you very much for your videos. It's all very interesting . You are the true Swiss Man!! Bye
Very interesting video. Obviously reflectors are the way to go.
thank you
Thanks for watching!
Und ich dachte im letzten Video, das du dich vielleicht zu spät entschlossen hast zu bauen, da es schon dunkel war, als du dein Dach gedacht hast.
Jetzt wissen wir das du hier wichtige Experimente durchgeführt hast! 😜
Haaaa ha haa haaaa, ja, das war haargenau so! 😆😆😆
Ich nutze als Reflektor eine Notfalldecke, allerdings Silber und Olivgrün, nicht Gold. Ein kleiner Schlitz zwischen Shelter und Notfalldecke reicht um den Rauch abziehen zu lassen. Zusätzlich ist das Feuer so kaum sichtbar für andere
Danke für den Tipp!
Hallo Felix
Das es wärmer wird, hat mit Konvektion und nicht mit Reflektion zu tun. Das ist ein Unterschied. Bei Reflektion spricht man von der zurück geworfenen Infrarotstrahlung. Bei Konvektion handelt es sich um bewegte Luft.
It makes sense.
Thanks a lot!
Wenn du die zwei Reflektoren mit Rettungsdecken auskleidest, hast du ein Grillfeuer und bist bald gar.
Ja, das stimmt!
enough reflectors, behind, each side, in front and on top ends up being a shelter. Ever wall or covering has got to increase and trap the heat from a fire. 🤣👍✌🥃
True..thank you!
😁
Yep, best fire is a fire inside a shelter, and under your butt! 😆
👍
Thank you!
Very well done, a good experiment and analysis of the heat radiation. I think that a lot of the confusion is mostly related to the word “reflector”
In most cases it’s radiator, wind barrier, depending on the materials.
Is it useful? I would say yes for reasons other than reflecting. Accumulating and slow releasing of heat, shelter, more light and protection and a wall behind a person will offer more insulation and capture the heat better with less wind to influence the temperature but mostly I find that the biggest benefit is the placebo effect it has on us.
Good video 💪
Thanks for your feedback!
PotAto, potato.
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!
Thanks a lot for your super interesting comment!
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
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!
This is the 100 Point comment!
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
Thank you so much my friend. And thank you also for your fantastic support. I can ask you everything..that's great!
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.
Nice work & great finding..
Thanks for your effort to make this video..
Keep it up..
They should be called fire-reemittors, as that's what they do, from a technical point of view. Reflection is something different
yes! that's what I was going to say. Its more about reemitting, not "reflecting"
Jepp, Mors Kochanski told it in a similar manner about absorbtion and re-emission. th-cam.com/video/6TYNiMx8tMA/w-d-xo.html&ab_channel=PaulKirtley
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.
@@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.
@@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.
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.
For me, it's worth the work for the extra heat. A well done experiment Felix. Thanks for sharing your knowledge.
Looks like the reflectors are effective to me!
Sorry i can't give you an answer if the reflector radiate heat? But it seems to work..yes!
Lucky you, Living in Switzerland!!! I would
Love to be there in
The woods camping
Out!!! -GARY. 🇨🇭
Thank you Gary. But dont forget.. the density of the population in Switzerland is very hight!
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
Haaa ha haa this is the 100 point comment!
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.
Thanks a lot for your interesting comment!
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 :-)
Hey Stephan. So schön von Dir einen Kommentar zu lesen! Liebe Grüsse in den tiefen Norden Deutschlands!
@@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
I never thought anyone could refute that . It seems common sense, and the same principle of reflecting heat is why space / emergency blankets work.
Thanks for your comment!
I agree, reflectors really do work. Thank you for the data to prove it.
See you next week. 👌😎👍
Thanks a lot James!
I’ve learned so much from your channel Sir. Cheers from Texas!
Thank you Andi!
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) ! 😀
👋🇧🇾✌️Thank's a lot & good Luck, Mr VixMan 👍🙏🤘!!!
There was one more scenario that I was hoping you would have done. Fire without a reflector wall, but with the shelter wall.
Yes... that's true!! Grrrr....
@@FelixImmler, even without that scenario, I think you made your point very well.
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
Dein neues Intro ist ja geil!
So viele alte coole Videos dazu verwendet! Spitze, wie ein Zeitsprung!
Danke, dein Feedback freut mich!
I must be old fashion as well as I completely agree with your opinion and analysis.
Thanks a lot Jacques!
Felix , good video and information , thanks for sharing ,God bless !
Thanks a lot Michael!
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
hello Nick. Thanks a lot for your interesting hint!
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.
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.
But as much i know infrared waves don't only reflect on a mirrow...
@@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.
This does not prove reflection of heat, it demonstrates that you are creating a micro climate of still air where heat can build up and dissipates slower, but whatever you call them a wall behind your fire and one behind you will keep you warmer than not having them
Great Video 👍Have you ever tried building reflectors out of woodlogs instead of stones? Always wondered if a woodenlog reflector is still working despite the small gaps in between the stacked logs. Gruess us Lachen ✌
Good question... no i didn't measured that..sorry!
I've used wooden reflectors; I'd say they make a significant difference. The logs also hold heat for a while once the fire is at the embers stage.
One advantage of the dry wood screen/planks close to the fire is that one can lean directly against them if on the other side the fire is controlled by another disciplined camper.
Thank you 4 the video and possible life saving tip
Thanks a lot for watching!!
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.
Hey Felix.
Interessante Betrachtung. Allein wegen des zusätzlichen Windschutz auf der Rückseite ist das absolut sinnvoll. Hab am WE extrem gemerkt wie ich am Rücken im Nierenbereich ausgekühlt bin weil ständig der Wind dagegen geblasen hat.
Beste Grüße, Matthias
Hallo Matthias! Vielen Dank für Deinen interessanten Hinweis!! Liebe Grüsse
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 👍
I will watch his video. normaly lars makes good videos. Thanks for this hint!
Excelent Felix, thank you for share!
Very well shown and explained. Thank you Felix
Felix I hope you see this one.. If you could only carry ONE Victorinox for the wilderness, WHICH ONE???? Thanks!
may be the Victorinox RangerGrip79
Almost all materials have some reflectivity in the thermal (5-13 micron wavelengths). Flat surfaces reflect better. Most (non-anodized) metals are very reflective, approaching 100%. Non-metals are also somewhat emissive, and for emissitivity, "flat" is not important.
Thank you so much for this super interesting feedback!
Very nicely done, if you had added a space blanket, to the shelter wall, it would have run you out… nice job
Thanks a lot for your kind comment!
Felix - I like it - but If you put a Mylar rescue blanket in front of the branches above you and in front of the rocks, you will get 80% of the infrared rays reflected. I hope I haven't told you any secrets now ;-)) pls. go ahead ...
Thanks a lot for your interesting hint!
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!
😁 the old 'triple heat' of working on your fire 😆
@@HAYAOLEONE exactly!😆
Very nice! Great information 👍! Thanks 😊 🙏
Thanks for watching!!
Agreed Felix, the effort may not always be worth it, seasonally though, it will be worth the effort (winter)!
👍
I totally agree with you 💪🏴👍🥩🔥🍺
Thanks a lot Paul!
I just think reflector is the wrong word. For me it's just an insulating wall stopping drafts of cold air coming in and slowing down heat leaking out.
Thanks for your interesting feedback!
Great video Felix! I’ve always thought I was warmer with a natural shelter and fire with reflector- now there is quantifiable evidence!
Thank you Sean!
Spot on Felix. I don’t know who thought otherwise but it wasn’t correct. The wall and reflector containing the heated environment is obvious. That’s the whole idea isn’t it?.
Yes...that's true!
Hi Felix, great stuff, well presented and an obvious plus benefit. regards Will.
Thanks a lot Will!
Your results make sense, great job in conducting this experiment Felix.
Thanks a lot!
Hi Felix, Very interesting stuff😊... To me you are bound to capturing some reflected heat on the inside of the Shelter you have proved. I wonder if the stone reflector was positioned in a "tight" U shape with the open end towards the shelter if It would increase the reflected heat even more. many thanks for sharing and hope you understand my point. Cheers Ian
Good thought!!!
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
Thanks for your hint!
Nice work. The experimental method you uses is good. Nice work.
Thanks a lot Roberto!
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.🇬🇧🇩🇪
Lonnie at far north bushcraft and survival.
Thank you..
But he said also that a reflector in the back is useful...
That's true but i wanted to build a shelter anyway😊...
Seems like some lazy bushcrafters came up with the idea that building these reflectors was too much effort and tried rationalize their decision by playing the science card. Thank you Felix for actually using the scientific method.
Btw, a flimsy space blanket against your inside shelter wall would have been a great 4th data point. And then the icing on the cake would have been to toss a plastic drop cloth over the shelter a’la mors kochanski for the 5th and final data point.
Yes, you are right!.. that would be interesting!
Danke Felix für den informativen Test 👉👍👈
Sehr gerne 👍
Thank goodness you understand the difference between radiant and convective heat!!! Lonnie was dead wrong and you proved it. His mistake was to measure air temperature which is grossly incorrect.
Yes..i saw the video..
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.
Thanks a lot for your feedback!
Did you try with an emergency silver blanket behind you at all? You can also put foil around the fire reflection wall. I think this increases the temperature more as more natural materials will absorb the light and heat.
No, but htis is for sure a good idea!
DANKE DANKE DANKE! Every week I wait for your videos!!!
Thanke a lot Mike!
Thats scientific enough for me. Thanks for the video Felix.
Danke Stephan!
If anything, having stones near a fire is a good thing for HEAT ACCUMULATION.
Good hint...thank you!
@@FelixImmler Thank you for making the videos. 👍