Often times camping in hot weather is a miserable experience. There's ideas, theories and myths of what works and what doesn't. I test some ideas here on tarp shelters to see if any of them work.
It's called 'latent heat of evaporation'. All refrigerator's work on this principle. To evaporate, water needs heat. It takes it from whatever heat source is nearest. The dampness in the grass will also have a cooling effect until it dries. In Australia they will pile brush on top of tin roofs to insulate and shade the roof which will work like your two layer tarp creating airflow and heat dissipation. In North Africa they build a sort of chimney which heats up and creates airflow through the house with fountains in the courtyard so the water draws away the heat as it evaporates. To cool yourself using water the most useful way would be to wrap or lie in a damp cotton sarong. Or a damp shemagh around the head. That way it takes the heat from your body first.
Lately when back packing in the sun, I've been wetting down and wearing a wicking material tee shirt, really effective , feels like your air conditioned! Also in stead of arriving at your destination with sweaty wet tee shirt, ive been getting where I aimed to with a tee shirt that actually dried finally from its initial cold water soaking.
Kevin, good comments. In Indio, California, where temperatures often reach 115 degrees or higher during July and August, I have learned that running the hose all over my head and torso, soaking my hat and cotton t-shirt, allows the relative temperature to drop 30 degrees or more, so long as the t-shirt stays wet. Repeated every hour or so, this will get you through a terribly hot day. Some beauty queens (male and female) are initially reluctant to compromise their appearance with a good soaking, but after seeing others survive the indignity, will usually give it a try. Remember to allow the super heated water from a sun-exposed garden hose to run out before soaking your head and body. The three factors of SHADE, MOISTURE, and BREEZE, working together, are more important than temperature for comfort. The body is able to reduce its own heat through sweating until temperatures reach 94 degrees, at which point the body cannot keep up and begins to absorb heat. Moisture -- even non-scalding warm water -- will immediately draw the heat out of the body, and then evaporate. A considerable amount of heat is required to turn liquid water to vapor. The breeze takes away the evaporated water, as the remaining water draws out more heat. Because air conducts heat and cold quickly, a shaded environment (under a wide brim hat, umbrella or unenclosed porch) is much cooler than under direct sunlight, especially in the presence of moisture and a gentle breeze. The combination of SHADE, MOISTURE, and BREEZE will save you and your companions from heat exhaustion and heat stroke.
@@clark57225 Thanks. Shade, Moisture, Breeze. Here in the UK at present we have more than enough of all three but the occasional heatwave can wreak havoc. 😓 My grandmother had a milk bottle cover made of a brown ceramic which soaked up water. It was placed over the bottle in a dish full of water. That thing could almost freeze the milk if the water was topped up. In Spain they use big fountains to reduce the heat in cities public spaces. A practice brought by the Moors of North Africa when they occupied Spain in the middle ages I believe. Lots of innovative uses of water for cooling before we started using dodgy refrigerator fluids.
Interesting experiments. Enjoyed watching and learning of the results. I have noticed a considerable thermal benefit in winter when using dual layered shelters even if the layers are something as thin as two tarps
@@Reallybigmonkey1 yea always good to know the weather patterns in your area for all seasons esp hot/ cold so to adjust air breeze to come thru or not.just watched your snake pit tent camp .great ideas for fire ty...yeah if you found four trees there in a box area you could put a rain tarp over when neccassary little incline maybe a couple feet longer each way at least.than the size of your tent.it should at least help or until you/us may need a new idea to learn...ty again
Reallybigmonkey1 - What about a white tarp? White/lighter colors reflects the sun - Black/darker colors absorbs the sun. BTW - I appreciate you & your videos. Hope you're having an awesome day.
Dave reminds me of Lonnie from Far North Bushcraft & Survival experimenting with a "fire reflector" or "heat reflector" (the wall you build behind a campfire), eventually proving that under the conditions he tested, it doesn't actually reflect any heat into a lean-to shelter on the opposite side. What it does, instead, is guide the hot air to rise directly behind the fire so that it keeps most of the smoke out of your shelter.
Interesting! The 2 tarp method sounds great for desert scenarios. Also, I'm going to turn over my auto sun shade and see if that makes a difference there as well.
My preferred setup for a tarp in the summer is a simple 'A' frame with the two sides at least a foot up off the ground to let a breeze flow through. I also build my fire at least 6 feet away to keep that heat from building up inside the tarp. I use a lightweight 8 X 10 silnylon tarp (I have a heavier weight one for cooler weather) and set up in the shade.
I want to add one more comment Dave. I just feel really good when I’m watching one of your videos. You’re the go-to channel that I want to watch when I want relax. Don’t change your intro greeting. I do some video work both for my enjoyment and also for CZcams. I know how much work goes into what you do behind the scenes with editing and such. Anyway, Grants Pass Oregon is watching and I look forward to the next one. Later, Steve Arnold
It’s so good to hear a guy that talks like you also acting smart at the same time. Like how you knew that the sun changing positions would compromise the results of your experiment. Saying that like a hillbilly only makes us look good.
I think to follow the canteen design, the wet blanket should be under the tarp. Evaporative coolers work great in our California dry desert, but not when humid.
Or just lose the tarp altogether and then you've got old school air con with the breeze coming through the wet blanket or wet sheet that's not being stopped by the tarp..? Which of course is dependant on there being a breeze of some sort of course. Just think of breeze/air hitting your sweaty shirt..cools you down.
Thanks, Dave! Your findings blew me away. Here's why. We used tents in Iraq 2003 and 2004. They were the old Aframe single layer plastic/rubberish covering. They were stinking hot! We put camo netting over the tents and it put some serious shade on the tents. After the net was up it was drastically cooler inside. Your findings made me say whaaa? 2 to 4 degrees difference? Dave, I realize that we had about 3 feet of distance between the camo net and tent. I believe that if you increase the distance between the two tarps, you will see a bigger difference in temperature. Or perhaps Georgia isn't the desert, right? Watery air vs dry air. Also, the canteen cooler does work in the desert environment. I kept a liter water bottle hung in a wet sock in the shade and it did cool hot tea water to a drinkable temperature. It's all due to rapid evaporation. It works in the desert but not really in Arkansas.
I love hearing from folks with desert experience. Like you said tho, it's dry there and very humid in Georgia. I hope to test the higher gap theory before Fall. Thanks for watching
Best part was scaring the cat with the hose 🤣 But seriously, very interesting. I didn't expect any of those results. Especially the reflective tarp, I'd have bet my last dollar that would have been the coolest shelter.
Dave is famous for loving cats! Check out the wonderful parody by Brooke Whipple of Dave's channel a couple of years ago! Brooke is just about the Queen of Bushcraft Comedy, as well as being a two-time pick to contest the ALONE challenge.
19:05 I did this same experiment! The double tarp, with an 8 inch air space, gave me 11 degrees cooler temperature. I got the idea when I saw an old man build a lean to cover his camper leaving a one foot air space. He swore it made his camper cooler. Of course, I had to find out for myself. Enjoyed the video, as usual!
@@Reallybigmonkey1 Direct sunlight. I couldn't believe the old man with the camper was right. I went back to the old man's house a couple of weeks later and thanked him for the tip.
@@Reallybigmonkey1 I did do something a little different from what you did. The top tarp was about two feet wider than the bottom tarp. I made an 8 inch gap in between the bottom tarp and the top tarp. But the top tarp had the sides flared out more than what your showing in your video. It may have helped the air circulate more. Just thought I'd mention it. You may want to try it.
Thank you so very much for taking the time to experiment with different setups and ways of doing things. It really helps. It's like watching bushcraft, and a science show in one. You're the MacGyver of the bushcraft world.
Great experiment my friend. Excellent information to know. Never would have thought of trying to find out if there would be any temp change. I'm like you, I just don't camp in the sun.😁👍
I was pondering the same question on the heat difference between the dark side and reflective side of a tarp out in direct sunlight. Awesome video you answered my question!
I’m very shocked that there wasn’t that a bigger cooling effect using a double tarp. Obviously, placing a shelter in the shade would be optimum. Great job Dave! Thanks for all your videos. -Stephen, Ohio
It has more to do with the ground being heated and air movement. Think of it like the freeze line in winter. After a long time below zero, the ground can be frozen 1'-2' down. So on a nice sunny day, the surface may heat up but it will still be cold several inches below the surface unless you have something that compounds the suns weak heat. So ever though you are in essence blocking out the sun, the ground will still be releasing heat for much of the day. The more sun great is blocked out, the quicker the ground cools and this will even cause air movement, further cooling the ground. In the trees, the ground never heats up. The tree tops heat up causing air movement changes to further dissipate heat.
@@Reallybigmonkey1 Great video. Love 'em all. So next experiment can you try different scenarios of cooling the ground (as mentioned in above comment) and keeping it cool in a bushcraft adventure.
This is a COOL experiment and video . Always great to see you happy , healthy and doing your thing . My 65 year old wife - "He is so adorable with lovely eyes .... and that voice" . No... you can't have her . She's filthy rich and helps me reload ammo . All the best Dave and thanks for your video .
Man brother... In a world of bright ideas and he said / she said, it is nice to see where the rubber meets the road... Thank you for taking the time to set that all up and share your results with the rest of us... And hey, perhaps we all learned something in the process... Excellent video bro... Thanks again... Peace.
I love watching your mind work. Another informative and entertaining video. I don't know if I'm setting up 2 tarps for 2 degrees but makes me think about the possibilities. Keep up the good work and see you in the next one!
You crack me up... I don't know if it's because I've watched you so long or not, but I was wondering about that double-walled (pup tent) tarp configuration with the air space when lo and behold you went and did it! Thanks for another great vid! You are about the only reason I have for visiting CZcams these days.
thanks for info...I live in the Mohave Desert, today was 112F and I've thought about it multiple times, what if the truck broke down, no A/C, no one around and we had to keep the sun from cooking us...? Just having water is not enough, though it may be the difference of life or death. I am also a steel building erecter. Two years ago we had to install the roofs on 3-326' x 90' buildings, galvanized metal over insulation with foil facing upwards. We baked in the 110-116F temps. I can tell you from that experience the sun exposure makes a huge difference. Inside the buildings without a breeze it was noticeably hotter than outside, but did not feel as hot as being in direct sunlight. A breeze helps a lot. What made the most difference on the second building was a battery operated, bucket misting fan. Cool off a few seconds with it every ten minutes and it was amazing how much better things were. If I had to guess, 30F cooler while cooling down. 5 of us went through 10 gal of water each day minimum. So my thought mixed with experience and your experiment hints at making a gravity-fed, or spring-tensioned-pressure mister used below a two layer shelter really could cool things off a lot. Hmmm, wonder if someone sat on a bladder if it would be the pressure needed to mist? I got work to do...
Thanks for the comments. I love your idea for a mist maker. I'm sure that will work great in the desert but probably won't here in Georgia due to our constantly high humidity. In certain situations I can see where it might help. Thanks for watching
Put something down and a cat will lay on it!!! lol A very smart and informative test Brother... Really good to know how all these materials act in the hot sun. Thanks for doing the hard work for us!! lol... Cheers!
It's not a horrible video Dave. I watch ur videos cause u give a lot of knowledge away for free . Things u could charge for but u care about ppl learning an getting out in the woods n to have fun. U are my favorite youtuber to watch. Thank u for ur the effort u put in n the enthusiasm u have while making these videos. Hope all is well with u n Nick.
I’m glad I’m not a betting man Dave because there is no way I’d have thought the reflective side out shelter would have been the hottest one. No way. I live in Texas where the dang asphalt boils in the summertime. I really appreciate this kind of information to help me keep my shelters cooler. Every single degree matters when it’s that stinking hot. Great information brother. Thanks for sharing.
For arctic camping, they use 2 or 3 layer tents with an inch or two of air between the layers for insulation. It would be interesting to know whether arranging your test with layers of air between would keep things cooler.
Yes it does,it is done in a desserts to,'trapped' air insulate in cooler as in hot climate Like a thermos,put something cool in it and it stays cool Put something hot in it,and it stays hot
they don't really, because the overall gain in insulation is outweighed by carrying all that extra weight. Traditional lavu's and tipi's are always single skinned, some modern ones have an inner tent but this is mostly to keep condensation and bugs out. If you want insulation in the arctic, we use snow. It's free and abundant and is the best all round insulator that you can get up there.
Great subject and handling on your part. Ron Hood covered this in his Desert Survival video., and the two tarp system is in official survival manuals (as is digging a pit to shelter in). There was a part in his video where he showed that using black material actually shielded the Sun's energy better than lighter material, hence the reason why the Bedouin dress in black. I'll have to go back and see the layering method though. Thanks for all your hard work and dedication!
Thanks Jeff, I'm glad you liked it. I believe everything Ron Hood taught but Im amazed at how many arguments folks get in over white or black for sun protection. Mors also says black tarps are better. Thanks for watching
Dave...i enjoy your videos most of all! They're educational for all ages that do not know about "bushcraft"...which... Thanks to YOUR channel, & others... it's making a comeback! I like how you keep scientific notes. This is GPD
"Fun with science.... and cats!" Much learned - and I learned that where you live it is damn hot weather! BUT it is not a good shelter, the cats refused to use it :(
In the desert we used canvas with a white liner on the inside, it was cooler than just the canvas. In the winter we used the same setup to keep the heat in. On my shelter now the two layers of canvas is cooler than one layer of canvas. Thanks for the test, take care.
Im guessing its because the canvas is thicker and heavier? No way UV rays can get through two layers of canvas but it can a poly tarp! Thanks for watching Quinn
Out of all I learned on this video that was the biggest shock of them all to me. I could have swore it would reflect the heat away. Thanks for watching Michelle
@@Reallybigmonkey1 It seems like one is to mistake "reflective side" with "side mirroring all wavelength". I would bet that a mirror made of metal would also heat up incredibly since the sunlight contains, I dont remember exactly, 1/2 of its energy within the lower (infrared) spectrum. Strange enough, if the reflecitve side is to keep one warm, the infrared part SHOULD be reflected back. But maybe just on a small bandwith of wavelengths? Tempearture of sunlight roughly 6000 K, temperature of body skin roughly 300 K ... :) I'm really curios how the temperatures would have evolved using a light blocking WHITE fabric (maybe made of cotton, not plastic). I believe it would heat up only slightls in opposite to a metallic mirror (compare car heating up in the sun...), even thouth a fictional metallic mirror would reflect all human visible wavelengths!
@@Reallybigmonkey1 No indeed I would suggest a white cloth outer layer and the inner layer - I dont know! Maybe just this one layer. But light-blocking white. There ar curtains made for blocking light (almost) completely. That ones in bright white. Propably won't make a good tarp material, could be hard to keep it clean :-D But for bushcraft sience, why not!
The reflective side will reduce the radiant heat but not effect the convection heat. The reflective tarp was in the middle collecting the convection heat from the other two tarps leaving the results inconclusive. It is same when a person in between two other people will be warmer due to the convection heat transfer. This does not include contact because that would add conduction heat transfer. Try the video again and put the tarp on the outside. Great video though.
Trevor Cassell I was thinking the same thing about the middle setup being affected by the side tarps. And also one end was near the tree casting a shade on the ground.
Great information. It made so much sense to me to use an insulation factor to keep cool. I actually have used a Grabber with a silk quilted blanket in white. Cools very nicely.
David that was a great experiment. I do believe I will carry to tarps for now on....... lol..... I want to be as cool as I can. Unless there's a lake near by then I'm cooling off in it. That's why I like camping in the spring or late fall. So much cooler. Have a great weekend, Chris from Missouri
Well ole Dave,first of all this is Aug.2022,I was trying to watch your video you put out today Friday 8-22 but couldn't find it yet but anyways I came up on this 3 tarp setup and was just wondering, since the reflective side out tarp made it hotter inside in the summertime would it also make it warmer in the winter to put the reflective side out or maybe in the winter put one reflective side in and cover it with one reflective side out .You are the scientist here so your input will determine what I try if I camp out this winter...I'm getting old and can't hardly sleep outside anymore,anyways thanks for your videos and I really look forward to watching them on Friday mornings with my coffee as the sun is coming up.Hang in there brother and your son,you guys are definitely making some great content videos
From the various experiments I've done with reflective mylar type tarps I'm convinced they do not work well in summer heat. Maybe there's a trick to it that I'm not aware of but no matter if it's inside or outside this material works incredible in cold weather. In recent times I'm finding it's more beneficial to just camp in the shade and try to funnel the wind into the shelter. Thanks for the comments and thanks for watching Dennis
great job. If we just think why these tarp set ups changed the temperature. If you think about a tree with all of the sun light being filtered out, yet allowing the wind to move through the trees, to a point the deeper the canapé the cooler it is under the tree. I wonder what the temp was under the trees on that day? I think that is why the dual layer tarps worked better. I wonder what would happen with 4 layers and air spaces. Another idea is evaporative cooling, the old refrigerators made with burlap. With air moving through water at the ends of the dual wall tents if that would cool it down, kind of like a swamp cooler, or does the air have to be forced through with a motor to get the effect you would want. Two more ideas, I remember a place in the southern desserts of Utah, by eagle mountain a tall cliff. It acted like a sail and the air would move down the face of it, into a crack that was shaded. If you sat at the bottom of the crack, the air was cooled as it came down in the shade, and was cold. I didn't measure it, but it was like 120 degrees in the sun but at the base the air felt as cold or colder than air conditioning, I would guess 50-60 degrees. Like a refrigerator. We also know if we dig in the ground below the frost line the earth stays at a constant 50 degrees. Like in the back of a cave. If you found a natural trench and with rocks and sticks create a 30 foot tube you could cover over with dirt and then create a draft to go through the tube and into a dual wall tent, as the air moved through the tube it would be cooled and create an air conditioning effect. Some ideas to try or think about how you could facilitate some natural occurrances.
Funny you should post this video just now as I have been staying with friends for the last three weeks and as their house was full, I used a tarp setup in the garden. I covered it with scrim netting type foliage which acted like a cover as in your video. Although it got hot, it was still better than another friend's tarp which was single skinned and boiling! 😡. It made for a very interesting watch and I did notice how your cat legged it when the hose came out. Hot or not, he didn't want to be the star of the show that day😊👍. Many thanks for the great entertainment as always.
Dave this is why I watch your videos, man we can all learn a lot. Interesting results for sure. I figured that with the silver side out would heat up the sleeping area more. Double tarps, lets face it cooler by 2 or 3 degrees does make a difference when staying under a shelter for comfort during the heat of the day. Well done my friend!
Thanks Daniel. Man I was shocked. I thought for sure that set up would reflect the heat away. I guess not. 2 to 3 degrees is better than nothing! I'm glad you liked it. Thanks for watching
In the eighties, a camera company did a test on which camera bag kept equipment the coolest. The lighter colors, were cooler for the first hour but after 4 hours in direct sun, they were all the same temp. inside the bags.
@@Reallybigmonkey1 You said in vid that you didn't understand how moisture cools. Have you noticed that when you get out of the shower, that your body is cooler until you are dry? Notice how when one soaks your canteen liner, the moisture is touching the product. The reason swamp coolers are not used in the south is because the humidity is too high for them to be effective, I think the next test would be to use a tarp for shade and the the damp blanket on the other side and ends to keep warm air out. Similar to keeping cold air out in winter.
It wouldn't be much better in the desert if their was a breeze. The constant flow of hot air across hot sand would not allow for the heat to be disbursed. In the dessert your back would have to be to the wind and the outer tarp would have to be further away to cad a shadow. Also you would have to remove about 2 inches of top sand since it holds heat very well. Don't use sand for a wind row because all you will be doing is allowing for hot sand to be carried back in. The break tarp would have to be almost ventricle and cast a shadow past the lean to to create any real change in temperature.
I like the video you did with the cool air off a creek tubed up to a tent. That made a great difference. Thanks. For the experiment. Sun bad shade good. 🤗
Thanks Marie! That was an excellent set up and for my area? That's the way to go. I feel sorry for those campers that have no spring fed creeks or shade trees. Thanks for watching!
This test was great 👍 thank you doing this and sharing it with us. I enjoyed and learned something! I thought for sure having the reflective side out would have been cooler. Lol.
In wanted to see double tarp setup with air space and wet blanket as bottom part of pup setup ... Soo you would have shade and evap cooling.... Love your videos Dave ...
Great video Dave. Maybe the pup tent configuration was slightly better overall as opposed the standard lean to tarp.... it's a cool 70 degrees here in Scotland. I'd swap that for your backyard ⛺🤠!!
Great video Dave. Thank you for the time you take to make these informative and entertaining videos for us. Your dedication to your channel and us hit home when you said you had to be to work in 30 min and there you were working on the video instead of relaxing before heading into work. Not so sure I could be as dedicated so thank you for your time and creativity.
You should try a white blanket. And black blanket. Blackbattracts sun while white or light colors should help reflect i worked outdoors alot. And found lighter color clothes keep me cooler
Evaporative cooling. The reason it works. Water or water gas (humidity) can change temperature at a very steady rate. Add, lets say. one unit of energy, and the water temp goes up one degree. One to one. But,,,, when water changes phase,, from liquid to ice,, or liquid to vapour,, the change needs or releases lots of energy. Your experiment involves taking water from 212 liquid,, to 212 vapour. Same temperature , but liquid to vapour. Now to be clear, evaporation takes place at all sorts of temperatures,, but on that little bitty scale of just one molecule,, the change really is boiling water. The energy required,, or in your case absorbed. So,,,, if it needs one unit of energy to raise the water temperature one degree,,, between 32 degrees, very cold but not frozen water,, to bring it to boil at 212 degrees you need 180 units of energy,,, 180 degrees change,, 180 units. BUT,,, to move the water just a little tiny, tiny bit to 212 degrees vapour,, just 212,, to 212 but liquid to vapour,, you need 1000 units of energy,, same temperature,,, just to push it past the phase change. Now the really cool part of water,, is it does not have to all be at boiling. If the sun kicks just one molecule out , if just one molecule evaporates,, it MUST steal some energy from all the liquid around it. When it steals that energy,, it cools the surrounding water. The high energy molecule,, vapor steam,, has to get that phase change energy from somewhere,, so it just takes abit from the liquid around it. You end up with a cooling effect. Same sort of thing happens when water changes to ice. Water gets colder and colder,, one degree at a time,,, but when it wants to shift from liquid water at 32F to frozen water at 32 F,, same temperature,, you have to take 8 units out just to shift it from liquid to frozen. That is why some ice in a cooler can keep things cool for so long. It is not just the cold ice,,,, it is that jump in changing the ice into liquid.
Awesome test there Brother! I too, was caught off guard by the reflective side not reflecting the sun rays and heat any better... thanks for over taxing Your Brain on this one...ATB to you and Yours.
Love this! So many people go with overly comnplex or insanely expensive solutions, when there are so many good ones, if you just apply yourself. Awesome little life hack that I put to the test recently... I was camping at high elevation, wet, and it got down into the 30s at night. I was sleeping in a hammock, so the cold was definitely going to be a factor. I bought one of those reflective sunshades for the front windshield of a jeep wrangler rubicon (I think it was about $9 on amazon, and only weighs about 4oz) and put it in my sleeping bag with me. I stayed so warm that my sleeping bag was unzipped all night, and I had a foot sticking out of it.
Amen brother it’s definitely hot here in upstate SC too. Great ideas. I remember reading somewhere that either the Greeks or romans would hang wet curtains in their windows for a type of air conditioning. It’s the same reason that we sweat when we get hot for the sweat to evaporate and cool us off. Always enjoy watching your videos. Keep up the good work.
I use a modern power pack to work a fan to increase evaporative cooling. At the margin, it makes a difference between relative comfort and discomfort for restorative rest.
@@Reallybigmonkey1 Summer max 38C, Winter -2C. Let's split it down the middle, shall we? 18C all year round. Deal? :D _Oh and Carol, stop touching the damn thermostat every two minutes. Put a sweater on or something_
This video was GREAT! Heading to a lake next weekend with 100+ degree temps and my big idea was to put up a tarp reflective side out. Guess not after this video. I must say I was really surprised by the result. Looks like the sun reflector just created a SOLAR OVEN under the tarp. Thank you for this experiment.
Why is it that I get seriously happy when I get a notification from my buddy and brother in machining Dave. Makes my day each time. Keep cool and stay safe man.
We have a few shade trees in the Arizona desert, but they lose their leaves to reduce evaporation. (that's why their bark is green). So thanks for doing this experiment. It means that if the car breaks down by the side of a isolated road, pull out a couple of tarps and get some better protection from the sun. ❤🌅🌵
Im guessing yall dont have many shade trees there? Yall also dont have high humidity so the techniques that work here may not work there or vice versus? Thanks for watching Suzi
i use the double tarp with an air space often and we can notice that 2 degree difference, i also feel like it blocks more uv rays or something? out here in the Mojave desert one tarp still feels like you are burning under it, but two tarps with an air gap makes a big difference and is much more comfortable. love watching tarp vids and really enjoy seeing you doing these experiments. thx for keeping an old topic fresh. you rock!
I just found this. Subscribed. Your result on reflective side out is why we test instead of just going with what sounds good. Great set up. I found the same thing. It roasted me when I tried it. My guess is that the reflective side only reflects the lower wavelengths of light that we can see plus infrared (much less energy). There's probably a plastic film over the aluminum layer to keep it from oxidizing. This plastic is probably UV stabilized which means it has a pigment that absorbs UV light but passes lower wavelengths. The problem with this is that the energy of a given ray of light increases exponentially with its frequency so that shorter, higher frequency wavelengths like UV have VASTLY more energy than visible light. The dark green side may be cooler because it reflects the high energy light near and including UV even though it absorbs most visible light.
I thought the double tarp with the air gap would have worked better. Now you got me wondering if a V-Wedge Tarp configuration or even a convex type configuration would help dissipate the heat better. I think your ultimate conclusion to stay out of the sun is the best bet! :D Thanks for the 'Cool' Vid Dave!
I thought you quit making videos! Noooo, CZcams unsubscribed me! Glad I figured it out.. I love your channel! At least now I have a lot of videos to catch up on. Great video btw! Very informative!
Nope, I didn't quit filming and to film for a long long time. I am happy you came back and resubbed! Plenty of videos to catch up on. Thanks for watching Kim!
all the warm air around you will just warm up the "cool" air. You have to enclose it to keep the cold air in and the hot air out but I expect you figured that out already. When I look at bushcraft from very hot countries, I have never seen any kind of shelter or device that will keep a living space cool. In the desert, they just get in some shade and stay still during the hottest part of the day, it's the only way. In the Jungle, we use the rivers and streams as heat sinks - get in the water and the heat will conduct it's way out of the body. It's still worth trying these things out and I appreciate you making videos like this, they are thought provoking.
Hi Dave. Glad to see you got your lawnmower working. Your grass was needing it in the last video. Ha Ha I noticed. On your tarp experiment, you might try putting the moving blanket under the tarp. I think that is were you need the insulation. I do like how you try different and new ideas. Give that a go. Personally I camp under a good tree covered area with the open end facing the breeze. On a lake of course in the summertime.
I tell you what Dave you really got me thinking. I was thinking copper blocks UV lights which are basically like x-rays that's where a lot of the heat penetration comes from but copper foil ain't cheap. So that got me to thinking about other materials such as window tint will block UV rays or green house shade fabric. Always glad to see you pop up here. And I will see you in the next one.
Desert camping, having a fly/tarp set up to shade your tent is very helpful. I don't like sharing my bedroom with spiders, scorpions and snakes so I do the tent thing. Air flow is key. Having a tent that maximizes air flow under the rain fly really helps - keeping the sundown side of the tent shaded by a fly of some sort helps too. If you are fortunate in campsites, you can find some relief from the afternoon sun by sitting under the fly, with a do-rag and similar evaporation gear on. Not camping in the hot part of the year is the best way to not be miserable.
One of the best videos I've seen. Not with a bunch of BS. Just facts about your experiment and the results. In desert survival, we were taught that 6 inches above or below the desert floor was cooler. I'd like to see the same experiment with the temperature checked at that height. Again, excellent job.
I have been using a tarp over my external frame tent for twenty plus years. After my wife got a bad sun burn, sleeping in a tent, I started adding a dark colored tarp over my tan colored tent. It kept her from getting sun burned again, and the tent stayed cooler. The frame of the tent keeps the tarp about 6 inches away from the tent on my Black Sheep tent, and I stake out the sides for the roof angle, which leaves a large dry area beside the straight up cabin tent walls for storing firewood if it rains.
Absolutely amazing study! AMAZING!! Living in W Central FLA on the Gulf of Mex I've wondered if there was a way to reduce this demoralizing heat and humidity....and by your last experiment it was a full 10 degrees cooler than the thermometer DIRECTLY in the Sun. Learned a lot.....a LOT! Thank you!
Another wonderful video, thank you Dave! In the name of science, consider trying to reproduce and improve upon some of the other most popular 'good ideas' for preparedness. I think your style and delivery will win the day, once again - and help us all examine and understand much better. Hat is off to you sir, keep up the great work!
Hey Georgia Dave!! That's what I'm going to call you. Hope that's ok. Anyway, I have a HUGE tarp that covers my tent, cook area, and plenty of seating. Did I mention HUGE?? Anyway, it does help so much. Although when the air is still, it's just hot, that's when the baby pool comes out. Hahaha. Some call it Glamping. I call it BUSHCRAFT! Lol I love a good experiment. Keep om coming. Thanks again. Nancy
Call me what ever you like as long as you call me for dinner. Lol. Thats my Dads favorite saying. Nothing beats the shade of a tree. I'm glad you liked it. Thanks for watching Nancy
Wow, that's all really surprising! I honestly expected the double-wall to make a much bigger difference than just 2 degrees! I'm especially shocked that the shiny side out didn't help at all! You need to pass that info along to the people that make the window sunshades for vehicles. I know there was good air flow because they were all open at both ends but I wonder if it would help very much to raise the "bottom" of each of them to allow for even more air flow. Or, even to have the tarp as just a (sort of flat) roof, with no type of wall at all. Anyway, thanks for doing all this research for us and letting us all learn from you.
Oh I was amazed at the results too! I'm guessing those window shades only reduce IN rays from cracking your dashboard. No way they reduce the actual heat in your car. Thanks for watching my friend!
It's called 'latent heat of evaporation'. All refrigerator's work on this principle. To evaporate, water needs heat. It takes it from whatever heat source is nearest. The dampness in the grass will also have a cooling effect until it dries. In Australia they will pile brush on top of tin roofs to insulate and shade the roof which will work like your two layer tarp creating airflow and heat dissipation. In North Africa they build a sort of chimney which heats up and creates airflow through the house with fountains in the courtyard so the water draws away the heat as it evaporates. To cool yourself using water the most useful way would be to wrap or lie in a damp cotton sarong. Or a damp shemagh around the head. That way it takes the heat from your body first.
Lately when back packing in the sun, I've been wetting down and wearing a wicking material tee shirt, really effective , feels like your air conditioned!
Also in stead of arriving at your destination with sweaty wet tee shirt, ive been getting where I aimed to with a tee shirt that actually dried finally from its initial cold water soaking.
@@neilblackman2965 Cool!
Thanks for the info Kevin!
Kevin, good comments. In Indio, California, where temperatures often reach 115 degrees or higher during July and August, I have learned that running the hose all over my head and torso, soaking my hat and cotton t-shirt, allows the relative temperature to drop 30 degrees or more, so long as the t-shirt stays wet. Repeated every hour or so, this will get you through a terribly hot day. Some beauty queens (male and female) are initially reluctant to compromise their appearance with a good soaking, but after seeing others survive the indignity, will usually give it a try. Remember to allow the super heated water from a sun-exposed garden hose to run out before soaking your head and body.
The three factors of SHADE, MOISTURE, and BREEZE, working together, are more important than temperature for comfort. The body is able to reduce its own heat through sweating until temperatures reach 94 degrees, at which point the body cannot keep up and begins to absorb heat. Moisture -- even non-scalding warm water -- will immediately draw the heat out of the body, and then evaporate. A considerable amount of heat is required to turn liquid water to vapor. The breeze takes away the evaporated water, as the remaining water draws out more heat. Because air conducts heat and cold quickly, a shaded environment (under a wide brim hat, umbrella or unenclosed porch) is much cooler than under direct sunlight, especially in the presence of moisture and a gentle breeze. The combination of SHADE, MOISTURE, and BREEZE will save you and your companions from heat exhaustion and heat stroke.
@@clark57225 Thanks. Shade, Moisture, Breeze. Here in the UK at present we have more than enough of all three but the occasional heatwave can wreak havoc. 😓 My grandmother had a milk bottle cover made of a brown ceramic which soaked up water. It was placed over the bottle in a dish full of water. That thing could almost freeze the milk if the water was topped up. In Spain they use big fountains to reduce the heat in cities public spaces. A practice brought by the Moors of North Africa when they occupied Spain in the middle ages I believe. Lots of innovative uses of water for cooling before we started using dodgy refrigerator fluids.
Interesting experiments. Enjoyed watching and learning of the results. I have noticed a considerable thermal benefit in winter when using dual layered shelters even if the layers are something as thin as two tarps
Thanks Lonnie, I'm glad you liked it. I have never tried dual layers in the winter. I may just have to. Thanks for stopping by Brother.
@@Reallybigmonkey1 yea always good to know the weather patterns in your area for all seasons esp hot/ cold so to adjust air breeze to come thru or not.just watched your snake pit tent camp .great ideas for fire ty...yeah if you found four trees there in a box area you could put a rain tarp over when neccassary little incline maybe a couple feet longer each way at least.than the size of your tent.it should at least help or until you/us may need a new idea to learn...ty again
Let's nominate Dave for the Nobel Peace Prize for science! Seriously, great job Dave. You followed the scientific method and proved a point.
I agree 100 %
Thanks!
Reallybigmonkey1 - What about a white tarp? White/lighter colors reflects the sun - Black/darker colors absorbs the sun.
BTW - I appreciate you & your videos. Hope you're having an awesome day.
great job Dave! if the Government did this scientific study it would have cost us Billions!
Dave reminds me of Lonnie from Far North Bushcraft & Survival experimenting with a "fire reflector" or "heat reflector" (the wall you build behind a campfire), eventually proving that under the conditions he tested, it doesn't actually reflect any heat into a lean-to shelter on the opposite side. What it does, instead, is guide the hot air to rise directly behind the fire so that it keeps most of the smoke out of your shelter.
Love your cat. You could call this video, "Cat and a Hot Tarp Roof."
ha!! love the title ;)
Lol!
Well played Well played indeed! LOL
Interesting! The 2 tarp method sounds great for desert scenarios.
Also, I'm going to turn over my auto sun shade and see if that makes a difference there as well.
Thanks Jeanette! Those auto shades are the same principle. Thanks for watching!
My preferred setup for a tarp in the summer is a simple 'A' frame with the two sides at least a foot up off the ground to let a breeze flow through. I also build my fire at least 6 feet away to keep that heat from building up inside the tarp. I use a lightweight 8 X 10 silnylon tarp (I have a heavier weight one for cooler weather) and set up in the shade.
Makes sense Robert!
I live in Tennessee and I've found the best way to beat the heat is with a 5 ton A.C. and tall cold iced tea. 😎
Or a nice stream with shade and a quality water filter 👍👌✌
Lol, I agree.
Some might call that cheating.....Not I.
Maybe a mint julep?
I'm in eastern Kansas and I couldn't have said it any better.
this is exactly the kind of things I wonder about when camping. thanks for trying out different methods for us...great video.
I'm glad you liked it Michael! I'm planning on some different variations of these tests this summer. Thanks for watching
I gotta leave in 40 minutes, so that gives me.....40 minutes. 😄
Lol, thats me thinking out loud.
@@Reallybigmonkey1 It made me laugh, thanks!!
@@outdoordauber It would have been funnier if Dave stated that he had 45 minutes for the experiment but 40 minutes before leaving.
That was really funny
@@Reallybigmonkey1 you always make me smile and laugh. I like the way you think
Very interesting video Dave. I really enjoy watching all your vids👍
Thank you Steve!
I want to add one more comment Dave. I just feel really good when I’m watching one of your videos. You’re the go-to channel that I want to watch when I want relax. Don’t change your intro greeting. I do some video work both for my enjoyment and also for CZcams. I know how much work goes into what you do behind the scenes with editing and such. Anyway, Grants Pass Oregon is watching and I look forward to the next one. Later, Steve Arnold
It’s so good to hear a guy that talks like you also acting smart at the same time. Like how you knew that the sun changing positions would compromise the results of your experiment. Saying that like a hillbilly only makes us look good.
Lol, thanks Chet!
Nice looking neighborhood Dave. Your lawn, plants and house look really nice. You have made it in life. The American dream is real. Enjoy my friend.
Thanks! Yep, it's a nice clean crime free area. I'm the only noisy messy resident here. Lol
I think to follow the canteen design, the wet blanket should be under the tarp. Evaporative coolers work great in our California dry desert, but not when humid.
We have so much humidity here in Georgia that this may never work here.
@@Reallybigmonkey1 Oddly enough, he said he was located in Georgia.
@@Reallybigmonkey1 OK I'm a moron.
Or just lose the tarp altogether and then you've got old school air con with the breeze coming through the wet blanket or wet sheet that's not being stopped by the tarp..? Which of course is dependant on there being a breeze of some sort of course. Just think of breeze/air hitting your sweaty shirt..cools you down.
And yep, look up 'tropical roof tent australia'.
I was surprised that the exterior facing, reflective tarp not only wasn’t cooler but was actually hotter inside. 🤔
Same here Jim. That shocked me.
I suggest we call it the "baked potato effect" LOL
@@Reallybigmonkey1 White is the only shade that would repel heat.
Thanks, Dave! Your findings blew me away. Here's why. We used tents in Iraq 2003 and 2004. They were the old Aframe single layer plastic/rubberish covering. They were stinking hot! We put camo netting over the tents and it put some serious shade on the tents. After the net was up it was drastically cooler inside. Your findings made me say whaaa? 2 to 4 degrees difference? Dave, I realize that we had about 3 feet of distance between the camo net and tent. I believe that if you increase the distance between the two tarps, you will see a bigger difference in temperature. Or perhaps Georgia isn't the desert, right? Watery air vs dry air. Also, the canteen cooler does work in the desert environment. I kept a liter water bottle hung in a wet sock in the shade and it did cool hot tea water to a drinkable temperature. It's all due to rapid evaporation. It works in the desert but not really in Arkansas.
I love hearing from folks with desert experience. Like you said tho, it's dry there and very humid in Georgia. I hope to test the higher gap theory before Fall. Thanks for watching
Never stop doing this. Your videos are really good and apply to the common man/woman.
Thank you Aaron! I hope to do this for a long long time!
Best part was scaring the cat with the hose 🤣
But seriously, very interesting. I didn't expect any of those results. Especially the reflective tarp, I'd have bet my last dollar that would have been the coolest shelter.
Dave is famous for loving cats! Check out the wonderful parody by Brooke Whipple of Dave's channel a couple of years ago! Brooke is just about the Queen of Bushcraft Comedy, as well as being a two-time pick to contest the ALONE challenge.
Lol, I'm glad you liked it. Honestly, the reflective tarp turned outwards was a shock! It heated up like I never expected. Thanks for watching
19:05 I did this same experiment! The double tarp, with an 8 inch air space, gave me 11 degrees cooler temperature. I got the idea when I saw an old man build a lean to cover his camper leaving a one foot air space. He swore it made his camper cooler. Of course, I had to find out for myself. Enjoyed the video, as usual!
Really? That's a huge difference! Was it in the sun or shade?
@@Reallybigmonkey1 Direct sunlight. I couldn't believe the old man with the camper was right. I went back to the old man's house a couple of weeks later and thanked him for the tip.
@@Reallybigmonkey1 I did do something a little different from what you did. The top tarp was about two feet wider than the bottom tarp. I made an 8 inch gap in between the bottom tarp and the top tarp. But the top tarp had the sides flared out more than what your showing in your video. It may have helped the air circulate more. Just thought I'd mention it. You may want to try it.
Excellent analysis....thanks for the work Dave....I was surprised by the results
Thanks Curtis! I was honestly surprised too
Thank you so very much for taking the time to experiment with different setups and ways of doing things. It really helps. It's like watching bushcraft, and a science show in one. You're the MacGyver of the bushcraft world.
You're very welcome and I'm glad you liked it Richard!
Hey, Dave, stay away from wet blankets in general, they're depressing. Yeah. Great video!
Lol, thanks for watching
Great experiment my friend. Excellent information to know. Never would have thought of trying to find out if there would be any temp change. I'm like you, I just don't camp in the sun.😁👍
I'm glad you liked it! I've always wanted to test this. Thanks for watching
Another excellent experiment from Dave! I never would have guessed that outcome. Thanks Dave!
Thanks, I'm glad you liked it Jeff! The reflective side out results shocked me!
I was pondering the same question on the heat difference between the dark side and reflective side of a tarp out in direct sunlight. Awesome video you answered my question!
Fantastic to hear that Jesse and I'm glad you liked it!
I’m very shocked that there wasn’t that a bigger cooling effect using a double tarp. Obviously, placing a shelter in the shade would be optimum. Great job Dave! Thanks for all your videos. -Stephen, Ohio
I was shocked too! Yep, nothing beats shade. Thanks for watching Stephen!
It has more to do with the ground being heated and air movement. Think of it like the freeze line in winter. After a long time below zero, the ground can be frozen 1'-2' down. So on a nice sunny day, the surface may heat up but it will still be cold several inches below the surface unless you have something that compounds the suns weak heat. So ever though you are in essence blocking out the sun, the ground will still be releasing heat for much of the day. The more sun great is blocked out, the quicker the ground cools and this will even cause air movement, further cooling the ground.
In the trees, the ground never heats up. The tree tops heat up causing air movement changes to further dissipate heat.
Great info! That makes sense
@@Reallybigmonkey1 Great video. Love 'em all. So next experiment can you try different scenarios of cooling the ground (as mentioned in above comment) and keeping it cool in a bushcraft adventure.
Related, insulated shelters may be expected to cool slower in the evening.
This is a COOL experiment and video . Always great to see you happy , healthy and doing your thing . My 65 year old wife - "He is so adorable with lovely eyes .... and that voice" .
No... you can't have her . She's filthy rich and helps me reload ammo .
All the best Dave and thanks for your video .
Lol, thanks! I'm glad you both liked the video!
She's never called me adorable . Congrats bro .
Man brother... In a world of bright ideas and he said / she said, it is nice to see where the rubber meets the road... Thank you for taking the time to set that all up and share your results with the rest of us... And hey, perhaps we all learned something in the process... Excellent video bro... Thanks again... Peace.
Thanks Brother! I had some theories on what would happen and none of them were correct. Lol. I'm happy you liked it and thanks for stopping by!
Look up solar chimneys. .
In the 1860s the military had a double wall teepee.
Thanks for sharing your videos.
Never heard of that, I'll look it up. Thanks for watching Willy.
I love watching your mind work. Another informative and entertaining video. I don't know if I'm setting up 2 tarps for 2 degrees but makes me think about the possibilities. Keep up the good work and see you in the next one!
Thanks. Ah well, as long as an extra tarp aint too heavy it might be worth a few degrees. I'm glad you liked it. Thanks for watching
Would more tarps be more cooling?
You crack me up... I don't know if it's because I've watched you so long or not, but I was wondering about that double-walled (pup tent) tarp configuration with the air space when lo and behold you went and did it!
Thanks for another great vid!
You are about the only reason I have for visiting CZcams these days.
Lol, we think a like! I'm glad you like what all I do, Thanks for watching
thanks for info...I live in the Mohave Desert, today was 112F and I've thought about it multiple times, what if the truck broke down, no A/C, no one around and we had to keep the sun from cooking us...? Just having water is not enough, though it may be the difference of life or death. I am also a steel building erecter. Two years ago we had to install the roofs on 3-326' x 90' buildings, galvanized metal over insulation with foil facing upwards. We baked in the 110-116F temps. I can tell you from that experience the sun exposure makes a huge difference. Inside the buildings without a breeze it was noticeably hotter than outside, but did not feel as hot as being in direct sunlight. A breeze helps a lot. What made the most difference on the second building was a battery operated, bucket misting fan. Cool off a few seconds with it every ten minutes and it was amazing how much better things were. If I had to guess, 30F cooler while cooling down. 5 of us went through 10 gal of water each day minimum.
So my thought mixed with experience and your experiment hints at making a gravity-fed, or spring-tensioned-pressure mister used below a two layer shelter really could cool things off a lot. Hmmm, wonder if someone sat on a bladder if it would be the pressure needed to mist? I got work to do...
Thanks for the comments. I love your idea for a mist maker. I'm sure that will work great in the desert but probably won't here in Georgia due to our constantly high humidity. In certain situations I can see where it might help. Thanks for watching
Put something down and a cat will lay on it!!! lol
A very smart and informative test Brother... Really good to know how
all these materials act in the hot sun. Thanks for doing the hard work for us!! lol... Cheers!
Lol! That is so true! I'm glad you liked it. Thanks for watching
Thank God! I was going to call a search and rescue! Glad your back!
Lol, Im still here John! Thanks for watching
It's not a horrible video Dave. I watch ur videos cause u give a lot of knowledge away for free . Things u could charge for but u care about ppl learning an getting out in the woods n to have fun. U are my favorite youtuber to watch. Thank u for ur the effort u put in n the enthusiasm u have while making these videos. Hope all is well with u n Nick.
Thanks Marcus! I love making videos an I love getting people to get out in the woods. Thanks for the comments and thanks for watching brother
I’m glad I’m not a betting man Dave because there is no way I’d have thought the reflective side out shelter would have been the hottest one. No way. I live in Texas where the dang asphalt boils in the summertime. I really appreciate this kind of information to help me keep my shelters cooler. Every single degree matters when it’s that stinking hot. Great information brother. Thanks for sharing.
Same here Jack. Man them results shocked me! I'm glad you liked it. Thanks for watching
Great idea my Brother! Thanks for taking the time to share it Dave.
All The Best....
I'm glad you liked it and Thanks for watching Brother!
For arctic camping, they use 2 or 3 layer tents with an inch or two of air between the layers for insulation. It would be interesting to know whether arranging your test with layers of air between would keep things cooler.
Right. Good information and thanks for sharing.
Yes it does,it is done in a desserts to,'trapped' air insulate in cooler as in hot climate
Like a thermos,put something cool in it and it stays cool
Put something hot in it,and it stays hot
they don't really, because the overall gain in insulation is outweighed by carrying all that extra weight. Traditional lavu's and tipi's are always single skinned, some modern ones have an inner tent but this is mostly to keep condensation and bugs out. If you want insulation in the arctic, we use snow. It's free and abundant and is the best all round insulator that you can get up there.
That's worth testing
Great subject and handling on your part. Ron Hood covered this in his Desert Survival video., and the two tarp system is in official survival manuals (as is digging a pit to shelter in). There was a part in his video where he showed that using black material actually shielded the Sun's energy better than lighter material, hence the reason why the Bedouin dress in black. I'll have to go back and see the layering method though. Thanks for all your hard work and dedication!
Thanks Jeff, I'm glad you liked it. I believe everything Ron Hood taught but Im amazed at how many arguments folks get in over white or black for sun protection. Mors also says black tarps are better. Thanks for watching
Dave...i enjoy your videos most of all! They're educational for all ages that do not know about "bushcraft"...which... Thanks to YOUR channel, & others... it's making a comeback! I like how you keep scientific notes. This is GPD
Thanks Mary, I'm glad you like what all I do. I love influencing others to get out and do things. Thanks for watching
"Fun with science.... and cats!"
Much learned - and I learned that where you live it is damn hot weather!
BUT it is not a good shelter, the cats refused to use it :(
Lol! I'm glad you liked it. Thanks for watching
How accurate are your thermometers with respect to each other? There could be some plus or minus differences between the thermometers themselves.
They all read the same when laid in the sun.
I dont think that little distance mattered since it wasnt in direct sun.
Thanks, Dave! I think this will be very helpful when I am stuck with a full sun campsite because no other ones are available.
Fantastic to hear that my friend!
In the desert we used canvas with a white liner on the inside, it was cooler than just the canvas. In the winter we used the same setup to keep the heat in. On my shelter now the two layers of canvas is cooler than one layer of canvas. Thanks for the test, take care.
Im guessing its because the canvas is thicker and heavier? No way UV rays can get through two layers of canvas but it can a poly tarp! Thanks for watching Quinn
I’m gobsmacked that the reflective tarp would reflect the sun but it didn’t. 🤷🏻♀️ loved the video Dave very interesting. 😀😀😃😄😄😁😁
Out of all I learned on this video that was the biggest shock of them all to me. I could have swore it would reflect the heat away. Thanks for watching Michelle
@@Reallybigmonkey1 It seems like one is to mistake "reflective side" with "side mirroring all wavelength". I would bet that a mirror made of metal would also heat up incredibly since the sunlight contains, I dont remember exactly, 1/2 of its energy within the lower (infrared) spectrum. Strange enough, if the reflecitve side is to keep one warm, the infrared part SHOULD be reflected back. But maybe just on a small bandwith of wavelengths? Tempearture of sunlight roughly 6000 K, temperature of body skin roughly 300 K ... :)
I'm really curios how the temperatures would have evolved using a light blocking WHITE fabric (maybe made of cotton, not plastic). I believe it would heat up only slightls in opposite to a metallic mirror (compare car heating up in the sun...), even thouth a fictional metallic mirror would reflect all human visible wavelengths!
So you're suggesting inner layer white cloth outer layer reflective material?
@@Reallybigmonkey1 No indeed I would suggest a white cloth outer layer and the inner layer - I dont know! Maybe just this one layer. But light-blocking white. There ar curtains made for blocking light (almost) completely. That ones in bright white. Propably won't make a good tarp material, could be hard to keep it clean :-D But for bushcraft sience, why not!
The reflective side will reduce the radiant heat but not effect the convection heat. The reflective tarp was in the middle collecting the convection heat from the other two tarps leaving the results inconclusive. It is same when a person in between two other people will be warmer due to the convection heat transfer. This does not include contact because that would add conduction heat transfer.
Try the video again and put the tarp on the outside.
Great video though.
Makes sense Trevor, thanks for watching
Trevor Cassell
I was thinking the same thing about the middle setup being affected by the side tarps. And also one end was near the tree casting a shade on the ground.
Great information. It made so much sense to me to use an insulation factor to keep cool. I actually have used a Grabber with a silk quilted blanket in white. Cools very nicely.
Thanks Gina! I'm glad you liked it. I need to further experiment with this. I like your white silk quilt idea!
David that was a great experiment. I do believe I will carry to tarps for now on....... lol.....
I want to be as cool as I can. Unless there's a lake near by then I'm cooling off in it. That's why I like camping in the spring or late fall. So much cooler.
Have a great weekend,
Chris from Missouri
Thanks Chris, I'm glad you liked it. Hard to beat Fall or Winter camping! Thanks for watching
Well ole Dave,first of all this is Aug.2022,I was trying to watch your video you put out today Friday 8-22 but couldn't find it yet but anyways I came up on this 3 tarp setup and was just wondering, since the reflective side out tarp made it hotter inside in the summertime would it also make it warmer in the winter to put the reflective side out or maybe in the winter put one reflective side in and cover it with one reflective side out .You are the scientist here so your input will determine what I try if I camp out this winter...I'm getting old and can't hardly sleep outside anymore,anyways thanks for your videos and I really look forward to watching them on Friday mornings with my coffee as the sun is coming up.Hang in there brother and your son,you guys are definitely making some great content videos
From the various experiments I've done with reflective mylar type tarps I'm convinced they do not work well in summer heat. Maybe there's a trick to it that I'm not aware of but no matter if it's inside or outside this material works incredible in cold weather. In recent times I'm finding it's more beneficial to just camp in the shade and try to funnel the wind into the shelter. Thanks for the comments and thanks for watching Dennis
great job. If we just think why these tarp set ups changed the temperature. If you think about a tree with all of the sun light being filtered out, yet allowing the wind to move through the trees, to a point the deeper the canapé the cooler it is under the tree. I wonder what the temp was under the trees on that day? I think that is why the dual layer tarps worked better. I wonder what would happen with 4 layers and air spaces. Another idea is evaporative cooling, the old refrigerators made with burlap. With air moving through water at the ends of the dual wall tents if that would cool it down, kind of like a swamp cooler, or does the air have to be forced through with a motor to get the effect you would want. Two more ideas, I remember a place in the southern desserts of Utah, by eagle mountain a tall cliff. It acted like a sail and the air would move down the face of it, into a crack that was shaded. If you sat at the bottom of the crack, the air was cooled as it came down in the shade, and was cold. I didn't measure it, but it was like 120 degrees in the sun but at the base the air felt as cold or colder than air conditioning, I would guess 50-60 degrees. Like a refrigerator. We also know if we dig in the ground below the frost line the earth stays at a constant 50 degrees. Like in the back of a cave. If you found a natural trench and with rocks and sticks create a 30 foot tube you could cover over with dirt and then create a draft to go through the tube and into a dual wall tent, as the air moved through the tube it would be cooled and create an air conditioning effect. Some ideas to try or think about how you could facilitate some natural occurrances.
Fantastic input and you've given me a lot to think about! Thanks for watching
Funny you should post this video just now as I have been staying with friends for the last three weeks and as their house was full, I used a tarp setup in the garden. I covered it with scrim netting type foliage which acted like a cover as in your video. Although it got hot, it was still better than another friend's tarp which was single skinned and boiling! 😡. It made for a very interesting watch and I did notice how your cat legged it when the hose came out. Hot or not, he didn't want to be the star of the show that day😊👍. Many thanks for the great entertainment as always.
Single wall definitely ain't the way to go. Double tarp and who knows, maybe even triple tarp? Take care and thanks for watching!
Dave this is why I watch your videos, man we can all learn a lot. Interesting results for sure. I figured that with the silver side out would heat up the sleeping area more. Double tarps, lets face it cooler by 2 or 3 degrees does make a difference when staying under a shelter for comfort during the heat of the day. Well done my friend!
Thanks Daniel. Man I was shocked. I thought for sure that set up would reflect the heat away. I guess not. 2 to 3 degrees is better than nothing! I'm glad you liked it. Thanks for watching
In the eighties, a camera company did a test on which camera bag kept equipment the coolest. The lighter colors, were cooler for the first hour but after 4 hours in direct sun, they were all the same temp. inside the bags.
Very interesting Carl!
Thanks Carl!
@@Reallybigmonkey1 You said in vid that you didn't understand how moisture cools. Have you noticed that when you get out of the shower, that your body is cooler until you are dry? Notice how when one soaks your canteen liner, the moisture is touching the product. The reason swamp coolers are not used in the south is because the humidity is too high for them to be effective, I think the next test would be to use a tarp for shade and the the damp blanket on the other side and ends to keep warm air out. Similar to keeping cold air out in winter.
Makes sense Carl
I wonder if the humidity was a factor. It would be interesting to see the results in a low-humidity environment, like the desert southwest.
Could be, we have super high humidity here
It wouldn't be much better in the desert if their was a breeze. The constant flow of hot air across hot sand would not allow for the heat to be disbursed. In the dessert your back would have to be to the wind and the outer tarp would have to be further away to cad a shadow. Also you would have to remove about 2 inches of top sand since it holds heat very well. Don't use sand for a wind row because all you will be doing is allowing for hot sand to be carried back in. The break tarp would have to be almost ventricle and cast a shadow past the lean to to create any real change in temperature.
I like the video you did with the cool air off a creek tubed up to a tent. That made a great difference. Thanks. For the experiment. Sun bad shade good. 🤗
Thanks Marie! That was an excellent set up and for my area? That's the way to go. I feel sorry for those campers that have no spring fed creeks or shade trees. Thanks for watching!
This test was great 👍 thank you doing this and sharing it with us. I enjoyed and learned something! I thought for sure having the reflective side out would have been cooler. Lol.
Thanks Jon, I'm glad you liked it. I was shocked at how that reflective side out turned out.
In wanted to see double tarp setup with air space and wet blanket as bottom part of pup setup ...
Soo you would have shade and evap cooling....
Love your videos Dave ...
Exactly what I was thinking. Rather than luging a heavy blanket, I think a wet bed sheet would do the same.
Thanks for trying this out Dave!
I am planning on more testing off camera. I'm glad you like the videos!
I thought about a wet bed sheet at first but then figured the thick blanket would hold more water longer. Thanks for watching!
Great video Dave. Maybe the pup tent configuration was slightly better overall as opposed the standard lean to tarp.... it's a cool 70 degrees here in Scotland. I'd swap that for your backyard ⛺🤠!!
Thanks! I'm glad you liked it. I would love some 70° temps here!
Great video Dave. Thank you for the time you take to make these informative and entertaining videos for us. Your dedication to your channel and us hit home when you said you had to be to work in 30 min and there you were working on the video instead of relaxing before heading into work. Not so sure I could be as dedicated so thank you for your time and creativity.
Thanks Larry, I'm glad you liked it. Lol, the curiosity of these experiments had me working up to the last minute! Thanks for watching
Very interesting. What did we learn? Reflection blankets will keep you warmer in the summer too! Hah! Video is much appreciated
'Who Wouldda ThunkIT?
I gotta say, I was shocked at how that turned out! Thanks for watching
Honestly, yeah i was shocked that it (reflection side up) was that pronounced on a lean to, of all shelters. Who woulda thunk it? Thats exactly right.
You should try a white blanket. And black blanket. Blackbattracts sun while white or light colors should help reflect i worked outdoors alot. And found lighter color clothes keep me cooler
Some say white, some say black. I need to test both colors on tarps and on blankets side by side.
Evaporative cooling. The reason it works. Water or water gas (humidity) can change temperature at a very steady rate. Add, lets say. one unit of energy, and the water temp goes up one degree. One to one. But,,,, when water changes phase,, from liquid to ice,, or liquid to vapour,, the change needs or releases lots of energy. Your experiment involves taking water from 212 liquid,, to 212 vapour. Same temperature , but liquid to vapour. Now to be clear, evaporation takes place at all sorts of temperatures,, but on that little bitty scale of just one molecule,, the change really is boiling water. The energy required,, or in your case absorbed. So,,,, if it needs one unit of energy to raise the water temperature one degree,,, between 32 degrees, very cold but not frozen water,, to bring it to boil at 212 degrees you need 180 units of energy,,, 180 degrees change,, 180 units. BUT,,, to move the water just a little tiny, tiny bit to 212 degrees vapour,, just 212,, to 212 but liquid to vapour,, you need 1000 units of energy,, same temperature,,, just to push it past the phase change.
Now the really cool part of water,, is it does not have to all be at boiling. If the sun kicks just one molecule out , if just one molecule evaporates,, it MUST steal some energy from all the liquid around it. When it steals that energy,, it cools the surrounding water. The high energy molecule,, vapor steam,, has to get that phase change energy from somewhere,, so it just takes abit from the liquid around it. You end up with a cooling effect.
Same sort of thing happens when water changes to ice. Water gets colder and colder,, one degree at a time,,, but when it wants to shift from liquid water at 32F to frozen water at 32 F,, same temperature,, you have to take 8 units out just to shift it from liquid to frozen. That is why some ice in a cooler can keep things cool for so long. It is not just the cold ice,,,, it is that jump in changing the ice into liquid.
Thank you for the explanation my friend!
Awesome test there Brother! I too, was caught off guard by the reflective side not reflecting the sun rays and heat any better... thanks for over taxing Your Brain on this one...ATB to you and Yours.
Thanks, I'm glad you liked it. Man that reflective test shocked me! Thanks for watching
Dave, shade is the key. Thanks for your hard work at your job and the hard work you do keeping us informed and entertained!
I agree, nothing beats shade. Thanks for watching Steve
What about a white tarp?? Would it reflect more heat?
Did u watch the video
@Timothy Mckee yes
I think so. Too bad no one makes a white one that I've found
There is another result of this test!
It is reasonable safe to say...Dave is changing clothing every day. :)
Lol, you are correct!
Love this! So many people go with overly comnplex or insanely expensive solutions, when there are so many good ones, if you just apply yourself.
Awesome little life hack that I put to the test recently...
I was camping at high elevation, wet, and it got down into the 30s at night. I was sleeping in a hammock, so the cold was definitely going to be a factor. I bought one of those reflective sunshades for the front windshield of a jeep wrangler rubicon (I think it was about $9 on amazon, and only weighs about 4oz) and put it in my sleeping bag with me. I stayed so warm that my sleeping bag was unzipped all night, and I had a foot sticking out of it.
Thanks! I'm glad you liked it. Very cool you had that pad it worked! Thanks for watching
Amen brother it’s definitely hot here in upstate SC too. Great ideas. I remember reading somewhere that either the Greeks or romans would hang wet curtains in their windows for a type of air conditioning. It’s the same reason that we sweat when we get hot for the sweat to evaporate and cool us off. Always enjoy watching your videos. Keep up the good work.
I need to test that. With our humidity tho, will it work here? I'm glad you liked it. Thanks for watching James
Now if you had an idea to get rid of humidity that would be brilliant....
I use a modern power pack to work a fan to increase evaporative cooling. At the margin, it makes a difference between relative comfort and discomfort for restorative rest.
If I could get rid of Humidity I would be a billionaire!
30ºC is about as much as we Brits can take before we die of heat exhaustion.
It works in reverse too, winter where I am is 25c overnight....22 or 23 we are breaking out winter woolies thinking we are going to freeze!
The reason I hate seasons...Somebody keeps messing with the damn thermostat.
I hear ya, Down south our summers stay between 32C and 36C for two to three months!
@@Reallybigmonkey1 Summer max 38C, Winter -2C. Let's split it down the middle, shall we? 18C all year round. Deal?
:D
_Oh and Carol, stop touching the damn thermostat every two minutes. Put a sweater on or something_
This video was GREAT! Heading to a lake next weekend with 100+ degree temps and my big idea was to put up a tarp reflective side out. Guess not after this video. I must say I was really surprised by the result. Looks like the sun reflector just created a SOLAR OVEN under the tarp. Thank you for this experiment.
Thanks! I'm glad you liked it and found it helpful. You hit it right on the head, it acts like a solar oven
Why is it that I get seriously happy when I get a notification from my buddy and brother in machining Dave. Makes my day each time. Keep cool and stay safe man.
Thanks Brother!
This video has solved lots of What if you and This way is the best . Thanks for your time it has helped a lot of us .
I'm glad you liked it. Thanks for watching DC
We have a few shade trees in the Arizona desert, but they lose their leaves to reduce evaporation. (that's why their bark is green). So thanks for doing this experiment. It means that if the car breaks down by the side of a isolated road, pull out a couple of tarps and get some better protection from the sun. ❤🌅🌵
Im guessing yall dont have many shade trees there? Yall also dont have high humidity so the techniques that work here may not work there or vice versus? Thanks for watching Suzi
i use the double tarp with an air space often and we can notice that 2 degree difference, i also feel like it blocks more uv rays or something? out here in the Mojave desert one tarp still feels like you are burning under it, but two tarps with an air gap makes a big difference and is much more comfortable. love watching tarp vids and really enjoy seeing you doing these experiments. thx for keeping an old topic fresh. you rock!
Two tarps absolutely helped. What got me was how the air temp was 88 but under the tarp was so much hotter! Just goes to prove what UV rays can do.
Interesting results and a heck of a lot of fun to watch.
I kept thinking there would be bigger differences.
Like you said find some shade.
Thanks Ken, I'm glad you liked it. The results amazed me!
lmao Your cat is like, "Why would you get a perfectly comfortable bed wet!?" Cute cat!
Lol, my cats are the coolest
@@Reallybigmonkey1 So are mine. Cats are the best!
I loved this video! Interesting results. Glad you put the thermometer outside as a control.
Thanks, I'm glad you liked it.
Boy this one brings back some memories. It was the first time we corresponded with each other lol. Wayyyyyyy! on back
And I remember filming this just like it was yesterday! Thanks for watching again Edwin
Great content man. Thank you for helping all us regular folk survive SHTF! And I also have a great time watching you too, its good fun.
Thanks, I'm glad you liked it. Thanks for watching
I just found this. Subscribed. Your result on reflective side out is why we test instead of just going with what sounds good. Great set up. I found the same thing. It roasted me when I tried it.
My guess is that the reflective side only reflects the lower wavelengths of light that we can see plus infrared (much less energy). There's probably a plastic film over the aluminum layer to keep it from oxidizing. This plastic is probably UV stabilized which means it has a pigment that absorbs UV light but passes lower wavelengths.
The problem with this is that the energy of a given ray of light increases exponentially with its frequency so that shorter, higher frequency wavelengths like UV have VASTLY more energy than visible light.
The dark green side may be cooler because it reflects the high energy light near and including UV even though it absorbs most visible light.
Thanks for the sub Tim and thanks for the explanation. That makes a lot of sense
@@Reallybigmonkey1 I experimented with the same kind you did. Different silver tarps might give different results
I thought the double tarp with the air gap would have worked better. Now you got me wondering if a V-Wedge Tarp configuration or even a convex type configuration would help dissipate the heat better. I think your ultimate conclusion to stay out of the sun is the best bet! :D Thanks for the 'Cool' Vid Dave!
Lots more to test but you're correct. Stay in the shade! I'm happy you liked it and thanks for watching brother
I thought you quit making videos! Noooo, CZcams unsubscribed me! Glad I figured it out.. I love your channel! At least now I have a lot of videos to catch up on. Great video btw! Very informative!
Nope, I didn't quit filming and to film for a long long time. I am happy you came back and resubbed! Plenty of videos to catch up on. Thanks for watching Kim!
Another outstanding video. Very interesting and informative. Thanks for sharing it, and I'll be looking forward to your next un
Thanks William! I'm glad you liked it
Be interesting to see the difference between a lined & unlined tarp. Brilliant as always Dave.
I may experiment some more off camera. Thanks for watching!
all the warm air around you will just warm up the "cool" air. You have to enclose it to keep the cold air in and the hot air out but I expect you figured that out already. When I look at bushcraft from very hot countries, I have never seen any kind of shelter or device that will keep a living space cool. In the desert, they just get in some shade and stay still during the hottest part of the day, it's the only way. In the Jungle, we use the rivers and streams as heat sinks - get in the water and the heat will conduct it's way out of the body.
It's still worth trying these things out and I appreciate you making videos like this, they are thought provoking.
Makes sense Matt. These tests prove nothing beats shade.
@@Reallybigmonkey1 Yep, and rivers. I dont know how you can stand it down there in those temps. I'd be on snake island sitting in the creek.
As soon as I saw the double tarp, I was like...Great scientific work.
Hi Dave. Glad to see you got your lawnmower working. Your grass was needing it in the last video. Ha Ha I noticed. On your tarp experiment, you might try putting the moving blanket under the tarp. I think that is were you need the insulation. I do like how you try different and new ideas. Give that a go. Personally I camp under a good tree covered area with the open end facing the breeze. On a lake of course in the summertime.
Lol, Nick cut it. Funny how if you think about it, a tarp may bounce off rays but a blanket may absorb them? Nothing beats shade. Thanks for watching
What we have here is REAL science. Keep'em coming and thanx for sharing.
Thank you Steve!
I tell you what Dave you really got me thinking. I was thinking copper blocks UV lights which are basically like x-rays that's where a lot of the heat penetration comes from but copper foil ain't cheap. So that got me to thinking about other materials such as window tint will block UV rays or green house shade fabric. Always glad to see you pop up here. And I will see you in the next one.
Ah, you got ME thinking Wesley! They make those copper knee and elbow wraps. Why not cover a tarp in that fabric? Thanks for watching
Desert camping, having a fly/tarp set up to shade your tent is very helpful. I don't like sharing my bedroom with spiders, scorpions and snakes so I do the tent thing. Air flow is key. Having a tent that maximizes air flow under the rain fly really helps - keeping the sundown side of the tent shaded by a fly of some sort helps too. If you are fortunate in campsites, you can find some relief from the afternoon sun by sitting under the fly, with a do-rag and similar evaporation gear on.
Not camping in the hot part of the year is the best way to not be miserable.
Very well said and I agree. Camp in the Fall and winter. Thanks for watching
One of the best videos I've seen. Not with a bunch of BS. Just facts about your experiment and the results. In desert survival, we were taught that 6 inches above or below the desert floor was cooler. I'd like to see the same experiment with the temperature checked at that height. Again, excellent job.
Thanks Ken, I'm glad you liked it that much. I never knew that about that desert
Hang in there and lots of luck some times we need it Dave .
Thank you Mike
I have been using a tarp over my external frame tent for twenty plus years. After my wife got a bad sun burn, sleeping in a tent, I started adding a dark colored tarp over my tan colored tent. It kept her from getting sun burned again, and the tent stayed cooler. The frame of the tent keeps the tarp about 6 inches away from the tent on my Black Sheep tent, and I stake out the sides for the roof angle, which leaves a large dry area beside the straight up cabin tent walls for storing firewood if it rains.
She got sun burnt in a tent? Amazing how powerful and dangerous UV rays can be. Thanks for the comments and thanks for watching Randy
Absolutely amazing study! AMAZING!! Living in W Central FLA on the Gulf of Mex I've wondered if there was a way to reduce this demoralizing heat and humidity....and by your last experiment it was a full 10 degrees cooler than the thermometer DIRECTLY in the Sun. Learned a lot.....a LOT! Thank you!
Thanks Scott, I'm glad you liked it. It amazes me what all can be done just by setting up plain ole gear in differing ways! Thanks for watching
Another wonderful video, thank you Dave! In the name of science, consider trying to reproduce and improve upon some of the other most popular 'good ideas' for preparedness. I think your style and delivery will win the day, once again - and help us all examine and understand much better. Hat is off to you sir, keep up the great work!
Thanks! I'm glad you liked it and the way I do things. I'm always searching for ways of improving camping methods.
Instant classic! This rates right up there with the coffee making video☕️ Great job Dave❤️
Thank you David!
Hey Georgia Dave!! That's what I'm going to call you. Hope that's ok. Anyway, I have a HUGE tarp that covers my tent, cook area, and plenty of seating. Did I mention HUGE?? Anyway, it does help so much. Although when the air is still, it's just hot, that's when the baby pool comes out. Hahaha. Some call it Glamping. I call it BUSHCRAFT! Lol
I love a good experiment. Keep om coming. Thanks again. Nancy
Call me what ever you like as long as you call me for dinner. Lol. Thats my Dads favorite saying. Nothing beats the shade of a tree. I'm glad you liked it. Thanks for watching Nancy
Another excellent experiment brother. I always thought that old shiny side out trick was bogus and you proved it. Thanks bro.
Thanks Brother Jim! I'm happy you liked it. Man the reflective side out shocked me! Thanks for watching
Wow, that's all really surprising! I honestly expected the double-wall to make a much bigger difference than just 2 degrees! I'm especially shocked that the shiny side out didn't help at all! You need to pass that info along to the people that make the window sunshades for vehicles.
I know there was good air flow because they were all open at both ends but I wonder if it would help very much to raise the "bottom" of each of them to allow for even more air flow. Or, even to have the tarp as just a (sort of flat) roof, with no type of wall at all.
Anyway, thanks for doing all this research for us and letting us all learn from you.
Oh I was amazed at the results too! I'm guessing those window shades only reduce IN rays from cracking your dashboard. No way they reduce the actual heat in your car. Thanks for watching my friend!