Wood Fire "Reflectors"

Thomas Linton

Thomas Linton

Joined
Jun 16, 2003
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I have repeatedly seen references to building a "fire reflector" out of wood. The writers praise how the "reflector" increases the warming effect of the fire. There are many pictures and drawings of "reflectors" that are walls of sticks or cord wood.

Here's the thing: if wood works as a reflector of radiant energy, why don't we see wood used in commercial products to reflect radiant energy? Cellulose liners for survival blankets? Wood reflector ovens? Wood reflectors for lanterns and flashlights? Wood mirrors?

Wood is an insulator. It does not conduct energy well. I can find no science on wood as a reflector.

If it's not reflection of radiant energy going on, what accounts for all the testimonials? Blocking the wind?
 
It will reflect some energy.
No one said it was efficient. There are better materials to use for reflecting the heat.
But, the woods are made of wood, so it gets used more.:)
 
Thomas Linton said:
I wonder if it "reflects" anything - especially if covered with bark as typically illustrated.
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It is called a reflector mainly, I think, for lack of a better term by whoever originated the idea and then that term was just perpetuated over time. I tend to think of it more as a "deflector" or a wall that helps vector heat where it is needed most. The wall of wood stops heat from radiating in that direction so therefore more heat radiates in the opposite direction. Building a fire at the base of a large rock works well also. It's sort of like making you home heating more efficient by closing off an unused room
 
Thomas, After years of making fires in the winter I am not covinced that using wood for a reflector has any merit for reflecting heat back at me. Out of all the posts I have ever posted where I have fires you do not see any of my fires with reflectors unless it is rocks. Wooden logs built up may act as a wind block but as for really reflecting heat back at you/me I have not found that they work like the books say. That is why I do not use them. Only by getting out and making a fire in the cold and then sit by it and then see how that goes then make a wooded log reflector and see if you really feel any difference. I have never found that to be. I know that if you build one it does not take long for the reflector to start on fire lol if it is to close to the fire. I have even put a thick layer of mud on the log reflector and still did not see any real difference.


Bryan

Bryan
 
Thomas Linton said:
I wonder if it "reflects" anything - especially if covered with bark as typically illustrated.
Click to expand...

It reflects more heat than will open space. I think it's a "better than nothing" approach. Maybe you should line it with your space blanket. Everyone carries at least a dozen of those, right? :D
 
Lots of the rocks out west have mica in them and you can feel the reflected radiation with your hand.

Perhaps the wood gets hot after time and radiates some heat itself.
 
The Mylar-faced blankets make wonderful reflector ovens. However, that is rarely mentioned as a use.
 
I know that if you have mylar behind you. and you have a fire in front of you it really radiates the heat down to you. here is a camp I made in Feb. of 2009
I made a survival camp and used a space blanket for my shelter and had a fire in front of it.

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here is a self portrait kind of. I just held my camera behind me and snapped the pic.

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last winter camp was a little different I used a space blanket again behind me to help heat the shleter.
IMG_1243.jpg

I got this shleter up a couple of week before winter snows came.

again I did not use a wooden type reflector since I have tried them out in the past and do not feel they really work. If a space put on one it might be a better
deal, I might just have to try that this year.

Bryan
 
Interesting thread. I've never tried it and only went on faith that it worked. Hmm...may have to try it.

Back to what Thomas said though. If wood is an insulator then wouldn't it stand to reason that the wood would NOT absorb heat and thereby the heat is going in another direction? However, that wouldn't necessarily mean the opposite(at you) direction which would satisfy Sicily's experiences.
 
sicily02 said:
Wooden logs built up may act as a wind block but as for really reflecting heat back at you/me I have not found that they work like the books say....

Bryan
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From my experiences I think used only as both simultaneously can it do/be either, but I agree with you on the actually reflecting heat part. Years ago we did a lot of hunting, as well as trapping and fishing commercially on the rivers here. In the winter time, with the colds winds sometimes whipping down the river gorge, we learned the real value of wind breaks when we practically lived on the river side for weeks at a time and were dressing out hides with bare wet hands. As long as the "reflector" is placed between, and either perpendicular to or pref in a wide V shape or arc pointed at, the prevailing wind and the fire, then then it blocks the majority of colder winds, the winds you do feel will be warmer than if the break weren't there. It may not absorb much heat back far enough from the fire not to burn but it will absorb some and be warmer than the other side of it and all heat radiates, and in the woods when it's really cold every little bit of extra heat comes in handy.Trying to make just a "reflector" of wood logs built parallel to the direction of the prevailing wind it would little or nothing to improve the situation.

I know how well the AMK blankets reflect heat from when I was testing the blanket to see how effective it was at reflecting heat back away from me in a lean too in high temps. When I walked between the blanket and the sun it was like I was standing in front of a huge radiant heater and the temp was bearable under the blanket. Would have been even better if built parallel to the prevailing winds.

IMG_1520.jpg


IMG_1519.jpg
 
Yeah. the idea is that something is better than nothing. It is quite and sadly true that the diagrams in books tend to be drawn up by folks who have never built or used one. And frankly, in a true survival situation, you're not going to be wasting time building a nicely reveted wall of interwoven sticks--you'd be improving your shelter instead.

The idea is to prevent building your fire on the top of a cold wind-swept hill, where the winds push heat away from you and make you cold and miserable. If your fire is built a few feet from anything, it'll get protection as a wind break and have a chance to warm the air around the fire.

Wood is better than nothing and easy to pile up around you. I also advocate good fire placement: a rocky area with large boulders is good. I have used a pine tree and surrounding bushes as reflectors: you can really feel the heat pushed back.

But no--wood is not going to act like aluminum foil and really force a lot of heat back to you. A reflector is more likely to prevent the loss of heat in the immediate area.
 
oh they definitely work, how well is tough to say w/o scientific testing- to me the bigger question is are they worth the energy/time to build one? it's a fair bit of energy and time expended that might be better served by laying in more wood for the fire, gathering insulation, fortifying your shelter, etc

on one of my outings this spring I went out w/ the clothing on my back and what I could fit into a bottle holder (read not much)- temps dropped into the 30's

I utilized a long fire, wood reflector, heatsheet lean-to and lots of natural insulation for bedding- I got ~ an hour sleep at a go before having to mess w/ the fire, but overall not a bad night out

the reflector needs to be relatively close to the fire (and you), the reflector needs to be the length of your fire and relatively gap free- imo this would be the last thing I'd consider when getting a shelter/fire together- if I've got enough firewood, adequate bedding and a sufficient shelter and still have daylight- only THEN I'd consider putting up a reflector

coffeeson.jpg


he'll be OK :D

isitmorningyet.jpg
 
I normally when camping in winter use a reflector. I stach the wood, then put a space blanket over it to reflect the heat into my lean to. waht I notice most is a slight increase in warmth, less wind blowing cold air in, but most usefull is the fact that the fire burns a good bit slower. Which means less getting out of my sleeping bag and re building the fire. Best benefit hands down
 
A relevant thread. My 42L backpack will only hold a 30 degree feather bag.

I'm wondering about what I'm gonna do in the Sierras in late September on my deer hunt (@ 8,000 ft).
 
Erasmus said:
A relevant thread. My 42L backpack will only hold a 30 degree feather bag.

I'm wondering about what I'm gonna do in the Sierras in late September on my deer hunt (@ 8,000 ft).
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Hunt from your car with heater on and the window cracked down. Then make a drive through Chico State college with the deer mounted on the hood. :D
 
Erasmus said:
A relevant thread. My 42L backpack will only hold a 30 degree feather bag.

I'm wondering about what I'm gonna do in the Sierras in late September on my deer hunt (@ 8,000 ft).
Click to expand...

do what UL backpackers have been doing for years, utilize your clothing as part of a sleep system- ie down jacket, warm bottoms, socks, balaclava- I'm able to eek ~ 10 degrees or so by wearing clothing that is packed anyways. Also a lightweight/breathable bivy (MLD Superlight for example @ 5.9 oz) will provide additional warmth as well.

last but definitely not least, insure the pad your using has adequate R value for the temps your expecting- if you pad is underrated you will suffer from underneath
 
mtwarden said:
last but definitely not least, insure the pad your using has adequate R value for the temps your expecting- if you pad is underrated you will suffer from underneath
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Plus one on this. Stepping up to 2 3/4" thermarest from a ridgerest closed foam pad I noticed a significant difference. I sleep as well now outside as I do on my bed at home.
 
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