If you're a little unclear as to the function of the panels, here's a bit more explanation. They aren't intended to act as a seal against heated air. They're primarily a radiant barrier. As the metal of the door heats up, that heat radiates from both sides of the door as thermal radiation, primarily in the infrared part of the electromagnetic spectrum. That's what you feel when standing next to the door -- not hot air, but thermal radiation, which is absorbed by your body. It's the same transfer mechanism by which the sun heats the planet across the vacuum of space. Without the barrier, the thermal radiation emits into the shop, where it's absorbed by the floor, the tools, and all the other mass in the shop, heating the whole space and taxing the air conditioner. The radiant barrier instead reflects that radiation back toward the door, where it's re-absorbed by the metal, forcing it to eventually radiate out the other side. Hope that helps! Regarding any air between the door and the panels heating up and circulating, the effect is minimal. As one helpful commenter put it, "Air is actually a pretty poor conductor, and the conversion of radiant heat to convective heat isn’t as substantial as you’d think." Also, why didn't I do something to prevent the sun from hitting the door in the first place? Unfortunately, something like a roll-up shade or an awning (which would have to be pretty big) just isn't practical at the moment, but I may do something like that in the future.
Hi! First time watcher, just glanced at your video history and subbed immediately ^_^ I'm an HVAC engineer. Your basic design, here, is pretty good, but you got a little bit of the physics slightly wonky. You seem like you'd probably be interested, so I thought I'd comment. I'm gonna overexplain a few things that I strongly suspect you (Wesley) already know because you're not the only person who will probably read this: First of all, when you think about insulation, heating, and cooling for a space, if you just think about temperatures, you're not getting the whole picture. Instead, you also wanna be thinking about the *rate* at which heat *moves* from one location to another. "Heat" is a type of energy that gives a substance a "temperature," but they're not the same thing. It can be tough to hold "heat" and "temperature" as different concepts in your head, so here's an example: tinfoil in the oven. Why doesn't tinfoil burn you when you pull it straight out of a hot oven? We know intuitively that, just like everything else in the oven, the tinfoil has to be the same temperature as the inside of the oven to begin with. That's the point of ovens! So, when your delicate, fleshy finger first makes contact with the foil, that foil's *temperature* is as hot as every other metal part inside the oven. The reason your fingers don't burn is that it takes very little *heat* to raise the *temperature* of a thin sheet of aluminum up to oven temperatures - so little heat that, when it all rushes into your finger as the aluminum's temperature equalizes with your body, you barely perceive it as "warm." Despite the layperson-aimed advertising, A/C units don't come in sizes based on "floor area" or "degrees." They come in heat-moving-rate sizes. When you think about this problem with the roll-up door, you don't wanna be thinking "the inside surface of this door gets too hot (temperature) on a hot day, so we should lower that temperature." You want to be thinking "heat moves too quickly through this door on a hot day, so we need to slow down that heat." When the shop heats up in the summer, it's because the walls are letting in heat faster than the A/C can push heat back outside. There are three main types of heat transfer worth talking about here: conductive, convective, and radiant: Conductive heat transfer is when heat is *conducted* through a physical material, or through contact between physical materials. Convective heat transfer is when a liquid or gas moves heat by physically rearranging the hot and cold parts of itself ("flowing") to move heat from one location to another. (You may be familiar with "convection" ovens that distribute heat more evenly by actively circulating the hot air inside.) Radiant heat transfer is kinda like magic; it's where heat energy is kinda "beamed" from one object to another as electromagnetic radiation without really impacting anything in between. It's tempting to think of "radiation" as being "that thing from nukes that'll kill you," but radiation includes all sorts of other phenomena as well: visible light, infrared light, UV light, FM and AM radio waves, WiFi waves, Bluetooth waves, microwaves, and so forth. I think most people would find it uncontroversial - perhaps even intuitively obvious - that heat goes from Hot Things to Cold Things, and not the other way around. It's also relatively intuitive that heat moves faster from a Hot Thing to a Cold Thing when the temperature difference between those two things is bigger. This is true whether we're talking about moving heat through conduction, convection, or radiation. The situation is simplest with conduction; twice as big a temperature difference between the Hot Side and the Cold Side means twice the rate of heat transfer between them. It's allllmost as simple with convection, though there can be some things about the way the liquid or gas moves that can make it not exactly proportional. Radiation is more complicated, but it still follows the basic "heat goes from hot thing to cold thing - bigger temperature difference equals faster heat transfer" rule. (For folks who aren't math-averse, the heat transfer rate is proportional to the difference between the fourth powers of the two temperatures, with both temperatures measured in degrees Kelvin or Rankine, not Fahrenheit or Celsius.) So! With all of that said: If we think about the barrier you've made (leaving out paint and adhesives for simplicity) we've got: outdoors > rollup door > a thin pocket of air > reflective foil surface > foam insulation > wood panel > indoors From an engineering perspective, we'd want to think about what the temperatures will be in between each of these steps, and what types of heat transfer will occur within each of these steps: The first temperature we care about is probably one of the most complicated ones - the temperature at the boundary between "outdoors" and "rollup door." On a hot day, the air might be 108°F, but anybody who's ever bought a windshield sunshade can tell you that the surface of the rollup door will probably be hotter than that if it's in direct sunlight. Most people have some intuitive understanding that, if the door was painted black, it would get hotter than if it was painted white. This is because white paint bounces back more of the sun's radiation in the visible light spectrum, and black paint absorbs more of it. As said in the video, making the door's surface reflective would bounce away even more of the incoming radiation, probably bringing the surface temperature closer to the 108°F "background" temperature of the air around it. Then, as the heat moves through the thin metal material of the rollup door, there would be a small temperature drop to the inside surface of the door. Most metals are so good at conducting heat that the temperature difference between the outside surface and the inside surface probably wouldn't be very big, but there would still be a difference - because, as we know, heat only goes from a (relatively) Hot Thing to a (relatively) Cold Thing. Then we get to the area where your (Wesley's) physics got a little wonky: the part where the heat traverses the thin pocket of air between the inside surface of the door and the reflective foil surface. In this air pocket, the primary form of heat transfer would be *convective* heat transfer. Specifically, the air next to the inside surface of the door would get warmer from that contact and begin to rise, rising until it hits the top of that air pocket, then turning to fall along the reflective foil surface, transferring heat into the foil surface as it goes until it hits the bottom of the air pocket and turns back up to rise, again. Air is a decent thermal insulator, all things considered; thin, sealed, circulating air pockets like this are why double- and triple-paned windows are better insulators than single-pane ones. Regarding your (Wesley's) radiation concept, there would be *some* small amount of heat radiation from the interior surface of the door to the reflective surface opposite, but not a lot. Moreover, the radiative heat transfer between the inside surface of the door and the foil would still go from the Hot Thing to the Cold Thing, overall. The reflectiveness of the foil is basically reducing the smallest piece of the overall heat-transfer-rate pie, there. Then there's the foam insulation and the wood panel. Wood is a better insulator than metal, but it's not great compared to purpose-built insulation foam. Insulation foam is also better than a sealed, thin pocket of circulating air. If you wind up wanting to juice up your design, here, you could do it by laying in another layer of foam of the same thickness. It'd literally be twice as insulating. Meanwhile, if we think about the test rig you built, it goes: outdoors > reflective surface > foam insulation > wood panel > indoors This puts the reflective surface facing the sun. There's a HUGE temperature difference between that sheet of foil and the literal surface of the sun, so making that surface reflective represents a reduction of a bigger piece of the overall heat-transfer-rate pie, compared to the location in the air pocket against the door. This makes the experiment not very representative of the final design. If you wanted a more representative test, you could seal up the outside surface of each of those test boxes with a sheet of metal comparable to that of the roll-up door. All that said, I think this is a great design that's probably going to serve you well, and I love the experimental approach you took for this design. I'm glad I found your channel!
@@brodyjohnstancliff4822 Wow Brodyjohn! That was a paper you wrote there. It was very interesting. Can I ask a silly ? though? If he painted the outside door, let's say chrome, would that be even better than the insulation? Or did I totally screw up what you were saying? I also wanted to say that you definitely have a way with words. Do you write often?
@@tracybowling1156 Well, without running the actual numbers, and without knowing the direction (north/nouth/east/west) the door faces, it's tough for me to say for sure whether just a shiny paint job would be better than just the insulation on the inside, but "both" would definitely be better than just one of the other. (The direction matters because it changes the amount of direct sunlight the door would get on a hot day.) Also, thanks very much for the complement! Explaining engineering stuff to people who aren't engineers is a big part of my day job, so I get a lot of practice. ^_^
for an extra bonus - why not build a narrow pergola over the door on the outside. Louvres angled correctly, or a deciduous vine (grapes etc) will provide added shade in the summer and let sunlight in during winter. Any heat you can stop from hitting the door in the first place would make the insulation barrier work better.
Ain't that just it, we figure out a solution to survive the heat just in time for the weather to drown us instead. Cheers from a fellow survivor of DFW.
You could also put a roll-up blind on the outside of the door so it doesn't get as hot to begin with. There would still be some radiant heat coming through the metal door just with outside air temp alone so these internal panels would help block the majority of that. Another benefit of the outside blind is you can have the roller door up (and panels tucked away) and have a nice shaded view of the outside if the weather isn't too hot. That's if you used a shade-cloth type material for the blind that lets some light through still.
This is a good suggestion and something people don't realize about window blinds. Yes they are blocking the sunlight but they are still letting heat in, because the the sunlight is still heating the blinds which are on the inside. It's much better to shade the window on the outside.
Long time viewer and fellow north Texas resident. RU-vid finally started suggesting your videos to me again and I'm so glad. I've binged all the ones I missed over the past few months. I hope to one day have enough money to get one of your signs made. I've always loved the Googie style and need one for our computer shop in a small Texas town. Keep up the good work. Your channel should be over 1 million subs by now, I just don't get the algorithm most of the time.
As a fellow North Texan who has struggled with this problem all summer (I remember the 108 degree days in July), I used EPS with the radiant barrier with magnets to hold it on... the magnets struggled at best and the tape or glue on the magnets would melt off due to the heat. You just handed me my next shop project with this beautiful solution. Storing the foam sheet when I want to open the doors SUCKS with magnets (10x4 sheets of foam like to blow away). I would buy you a tasty beverage if I bumped into out and about North Texas.
wesley you are a very smart guy, it is a pleasure to watch you solve a problem using science. like you did with your loft lift . you make great videos that people can really get something out of and fallow along. there a lot of videos on youtube were people buy and not make things that they say they did make, then try to show you some thing about it and how to use it when they don't know them selves. it becomes a waste of time and an insult to your intelligence. please keep making your great videos mr wesley
This was a super satisfying/inspiring video for anyone trying to get a workshop together! Love the "numbered objectives" format, thank you for another great video!
I live in Hurst and have done nearly the same in my garage. Thankfully I have an east facing garage door, but it doesn't matter much, as I go multiple clothes changed a day when I'm working out there. A window unit in the wall helped a lot!
I have an issue in my bedroom with my wall facing full sun most of the day. Can I do this in my bedroom wall? I don’t mind putting it on top of the wall do you think that might help? The room gets incredibly hot and I have to use a window unit in addition to my central air because of course this is the room I sleep in and I can’t change it for another it’s the largest one
@@sharonnewmanehrlich7203 you mean a window unit in the wall? I should of clarified, I put it in an unused door. If you want to put an a/c in that room, I'd recommend a mini-split. That would keep the room as cold as you wanted. Otherwise if you want to cool the room, the only solution is shade, heat reflection paint outside or more insulation...
Just wanted to mention that the pink stuff really is genuinely closed cell foam. I was too cheap to buy a new hot tub lid and made a DIY one out of this pink foam. It's going on in 10 years and it's in perfect condition but more impressively it is still virtually weightless. It has not absorbed any water at all and if you've ever owned a hot tub you know that the $600 factory covers end up a hundred pounds after 3 years. Can't recommend it highly enough for that purpose. Originally re-stuffed the original lid but eventually replaced with a one piece attached to plywood with a pulley and LED lighting on the underside. It's actually quite a bit more efficient than the factory cover because I have two layers of foam, one that fits in the cutout and the second layer on top. Makes her a very good seal that doesn't require a straps or anything for wind
Great video!!! speaking from experience one thing though you might want to consider painting the outside metal of the door the whitest paint you can find, i know it may seem like the silver metal would reflect a lot and it does compared to black paint but pure white is way better and its comparatively very cheap, as a general rule i find that the harder something is to stare at directly in full sun the less it's going to heat up. It's actually ridiculously amazing how much less heat something by being completely white, if everybody painted their roofs white so much energy would be saved in AC.
Bonus: The mirrors will allow you to more adequately ponder your relative cuteness vs. Matthias. Great build - love every bit of it! The boop on your lab assistant’s nose was a gem.
Just a curtain outside with two of the Harbour Freight 10 x 8 black shade tarps using a rope or cable as a curtain rod between a couple cleats or brackets will cut the temperature on the outside of the door substantially. The shade tarps are grommeted already and relatively cheap and durable, just add some magnets to the bottom if desired but they let plent of air through and work great as ac unit shades also. If Im the hundredth person to say this stuff then disregard this comment. Enjoying your videos though.
You should paint the outside of the door white,you would reflect a lot of heat. A white blackout outside curtain,would also do a lot to lower temps on the door. The point is to not get steel to warm up,not so much to avoid it to transmit its heat to the inside.
The door was already white as far as I could tell. He also mentioned that in the video. But regardless, it’s a good point in general. However anyone following your suggestion may be disappointed with the result, given it’s still going to be pretty unbearable inside the shop once the white door has absorbed all the heat possible
@@cpzmelbs "bare steel door" is what the says. How can the door can heat up if it's in the shadow of an exterior curtain ? It will be at ambient temperature,not more. That's is what shadow is doing,avoiding heat to be absorbed.
Very nicely done! The other problem with using magnets is that if they get hot enough they lose their magnetic properties until they cool - which is used in rice cookers
If you make shroud around the door including the drum (it would need to project further from the drum) and add doors ti the shop side, you can get a better containment of the heat. This also creates a plenum, which you can then exhast to the outside further increasing the thermal preformance.
I just installed one of those pink fiberglass insulation panel kits on my garage door. I was disappointed in what little difference it made. You have given me new inspiration and hope for a cooler garage! Great video as always!
Thanks! One video I watched recommended foil-covered panels that fit in the spaces in the garage door, with the foil toward the door, but big enough that they curve out away from the door to create the necessary air gap.
What a great build--the change in temp is certainly very much appreciated. The folding screen will probably also help keep the heat INSIDE during the colder winter months. [not sure why some people think the space-saving ship's stairs (or ladder) you built are especially hazardous--they've been in use for decades]
I too live in north Texas. I work out of my garage with the metal door facing north west and my exterior wall getting a FULL western facing brick. Plus, since I live on a cul-de-sac that gets LOTS of sun. Thanks for the video. I've also become a fan to the brand AtticFoil so I'll be mixing their product with your results.
A couple of the links in the video description are videos by AtticFoil. They do a great job of explaining the effectiveness of a radiant barrier and the need for an air gap.
Great idea and execution. Gonna find a way to add this to our new house. What I would add to this is a screen for hot but windy days to prevent bugs coming in. A shade or carport to shade the door. Trees or tall bushes to shade the driveway, house, or door. Make the barrier a roll down to save space.
I love the knowledge and the information you put into your, useful, videos. Thank you and I wish I was your neighbor so I could work with you on your projects.
Aw this video landed at exactly the right moment :) Currently looking at insulating a 14 sq ft roof and weighing up the options. Foil backed foam held a few inches below the roof surface (single thickness of 1950s 'cement with mineral fibre' corrugated roofing) held in place by batons attached to the roof trusses currently looking like the preferred option. Your immense door panels reminded me of the sort of stage flats my dad built in the 60's, especially when you added the huge stars :) Fab!!
@@sgsax yup, those are Hollywood (aka Studio) flats alright! I was laughing my arse off at that fact when @Wesley Treat read the stickers from the Luan maker about which side was the front as that is super important when making a flat. Seeing his degree comment above (I have a tech theatre degree too!) explains why he found it just as funny. :)
Long Island, New York, late summer: 100°temp, 100° humidity but no rain. Suddenly the clouds roll in the air turns greenish. Then . . . FLASH BOOM All heaven's buckets empty at once and AAAAH ! Finally, a cool breeze.
My garage door faces west and I can't work in my garage shop with outside temps around 106 here in Austin. Very informative and entertaining. I enjoy the jokes as we seem to have similar tastes in humor. I'll check out dune more if your videos.
That was a great way to sneak that "SUBSCRIBE" reminder in there. And me mentioning it in the comments is a sneaky way to remind people they need to subscribe. 😁
I have this exact same issue in my shop. I had the same idea you had, but first I was going to hang a light colored drop cloth on the outside like a shower curtain that slides to the side to open the door. My door is dark green so the lighter color would make a big difference.
I believe the silver stuff needs an air space on the hot side to be most effeective. A permanent cloud or awning outside over the door would be very effective.
NASA uses multi-layer insulation. The new Webb space telescope uses 5 layers of mylar, separated by a foot or so of vacuum. Each layer gets them down almost 100 degrees C. If you had the ability to space out the mylar sheeting or put in multiple layers, you'd get even better effectiveness. It would be really interesting if you could build another set of these and put them on the OUTSIDE of the structure, and reflect the sunlight before it gets to the metal. Really interesting project!
If you could rig up a water spray/mist line to spray the outside of the door every few minutes/a few times per hour, You would remove a lot of heat from the door due to evaporation. It would drop the temperature of the door quite significantly.
I have that same door and in north Texas too. I used 4x8x3/4" foam board with the foil and taped them together similar to how you did yours. It does make a HUGE difference. I used a FLIR camera and it was very easy to visualize the temperatures.
Great video and your 100% on the science which I love to see. I appreciate that you actually did some research on the subject. My garage door is insulated BUT the manufacturer didn't leave an air gap. Instead they just glued foam insulation too the door which experienced direct sun for most of the day. It's usually only a few degrees cooler in the garage than outside. At least it's not in the sun 🤣 I laugh because otherwise I'll cry. Also because of local building codes, builders here so not insulate the walls not facing the living space or above garages so insulating the door doesn't have a huge effect. They save about $100 on insulation (they but I'm bulk) and our cars, tools, things and ourselves suffer 🥺
Beautiful door, going to remember this if we ever move to a place with giant floor to ceiling windows... Those types of stairs are extremely common in the Netherlands - they don't seem to have a higher death rate as a result of this....
The bubble wrap style is useful for odd shaped areas. I used it on my bedroom window because I’m last in line for the AC and my room faces south. It used to get crazy hot in here as we have no yard shade and i can’t fix anything, rental. I used a sheet along with some duct tape (for it’s heat resistance) and closed off my window. That plus some thick curtains cooled my room by probably 20F in the hottest part of the day. Bonus it made it pitch black in here at night which is nice for sleeping. Bonus anyone looking from outside thinks I’m some weird UFO conspiracy nut or have a meth lab in here lol.
If you have a window that has sealed gas inside it, it can pop the seals and void your warranty if there is one. I used tint on my window and it mentioned it could but as it was western window in florida with no shade from about 12 til sunset it had long ago leaked out.
If u add the strips with the the bubble wrap it will take it from r6 to r8. Good luck with the heat. Also think about flipping the unit if you all have another hard winter to keep the heat in as well.
I love your analytical approach to this, along with the great commentary and video! Just got this suggested in my feed and you've got a subscriber out of me already!
LOL my Galvo iron workshop here in Oz gets a bit hot as well. In Summer it gets between 50 to 60C in there even with the doors open and the pedestal fans running. In your scale that is 122 to 140. I haven't bothered with insulating, it is easier to just go fishing and wait for the evening to get the jobs done.
