Adam Savage here in my cave with myfriend Kipp Bradford how are you sir good and you very good I'm excited because weare about to explore a new Vista of cosplay technology now if you're aregular follower you know that I built myself a spacesuit from alien JohnHurt's suit and I wore Don the comic-con floor in San Diego in 2012 2014 in 2014and I almost got heatstroke wearing basically what was a quilt with armorattached to it so the very following year Chris Hadfield and I walked thefloor in a pair of 2001 spacesuits the silver clavia suits into which I'd builtan integral cooling system comprised of a bucket of ice water with arecirculating pump and cool shirts and that worked pretty well but Kip amongmany other things that he has done in his life as an engineer happens tospecialize in extremely tiny refrigeration units and we're hoping tobuild one here in the cave today small enough for me to use in cosplay so getready we're gonna get cold alright Kip where where do we startthere's a lot of little bits and bobs around the shop I'm not even sure I knowwhat this is yeah okay so where do we begin Adam this is that compressor okayoh this is the step that does Boyle's law that yes brings refrigeration andrecirculates the this stuff yep our gas that so what is it you compress it whenyou release it from compression the temperature lowers corrects and you getthe refrigeration that's exactly it so the compressor works just like anycompressor does there's a piston inside here in this case the piston is a rotarypiston so it spins around and as it does so is it a vane pump these are the vanepocket as a vane pump it sucks a gas into this inlet pulls it through thecompressor and increases the pressure just like Boyle's law PV equals NRT asyou increase that pressure the heat also temperature goes up because we're we'redoing mechanical work we put electricity in here that electricity is what's doingthat pumping right magnetic field turns the rotor the rotorthe vein the vein squeezes the gas we're doing work on the gas right so just likeif you're pushing down on a bicycle pump it can get hot it gets hot as you'redoing that work so the energy from your arms is transmitted into the pressure ofthat gas so gas gets hot as we do work to it and it gets compressed we can pushthat hot gas through another heat exchanger where we blow air over it andtake that heat away and when we take the heat heat away we're not just removingheat we're actually compressing the gas as well or we're actually just removingthe heat okay so the pressure the pressure from this output side staysconstant mm-hmm the temperature is what changes so wetake that constant pressure gas we blow the air over it and the reason why thepressure doesn't change is because even if we take all that heat away the gasitself is there's more new gas coming in from the backend so what happens is notthat it changes pressure but changes state we go from gas to liquidI see so because we're taking temperature out we can fit more gas inthe same volume we can fit more gas in the same volume okay that converts to aliquid and that liquid then goes to the other half of the system where we boilit off and what waving it off is how we get lower the temperature exactlyexactly see I don't have a refrigerator worksI'm logged that in my time just a little bit it's if you're an engineer you'llnotice as a reverse Rankine cycle okay a thermodynamic cycle that's fully closedloop and we do work with a piston or rotor or some kind of machinery thatdoes that compression so we're putting mechanical work into the system and wego from electricity to mechanical work to thermal and then we get rid of thethermal and then we reverse and come back on the cold side boil off turn to agas and the waste suck gas back in the inlet and it strikes me that this is anespecially tiny compressor am i right this is this is this is this one of thetiniest ones this is one of the tiniest compressors and this has a prettyfascinating story at the first Gulf War DARPA put out a callfor man portable wearable environmental control system Oh for just the exactthing we're exactly working on and they were did an RFP for tiny compressors yesand two companies one that RFP and one of those companies is Aspen compressorin Marlborough Massachusetts these are made in Kentucky the design of thecompressor is a fascinating MIT mechanical engineering PhD of course ofcourse makes these incredibly well balanced super small high-efficiencycompact compressors and when you say well-balanced that means that thecompressor is efficient because it's not losing any of its energy to vibration sowhen it's highly balanced you have a smooth system and all the energy isgoing where you want exactly and it means that if you're if you're wearingit you're not gonna get all that but vibration on tears Oh back it's notgonna make a ton of noise if you ever have your shop compressor turn on in themiddle of night and you hear that man oh I have to put a timer on apposite wakesmy neighbor's up exactly yes I know a normals live upstairs and sometimes wemake their lives worse I don't know they've never complained about the kindof music I love the story okay so the great thing about the DARPA story isthat DARPA puts this call out and they get a couple companies that respond toit with these super compacts and compressor technologies and they quicklyrealize that putting people in spacesuits in the middle of the deserttrying to fight a war is a bad idea right because if you have any kind ofsystem failure they're super compromised right awayimmediately compromised but we get this cool technology out of it and thisnotion that we can make very compact refrigeration and cooling systems usinga portable low voltage DC compressor technology so the original purpose ofthis being fighting wars with with people in these crazy suits yeah not thesmartest idea the result has been I think fairly transformative for a lot ofmedical applications I use these for a medevac system that couldstabilize people's temperatures in medevac helicopters after traumaticinjuries on their way to a hospital their way humbly nothing substantive isgetting done you can actually bring their doctors down Wow so found someother uses for it made some fun projects and the last system I built was theworld's second smallest wearable air conditioner couldn't quite get it to bethe smallest just got to be the second smallest and that is currently in a NASAspacesuit simulator that's running around somewhere in the world pretendingto be in Mars oh simulation space they're kind of like what the guys arewearing on high seas experiment it was the high so okay Oh fabulous fabulousthe the thing we're gonna build is a replica of the high seas basically airconditioner oh my god I'm that's really exciting one I follow the high seasexperimentation project for years obviously I revere what those guys haveput themselves through and I know the complications of that program but also Ilove those suits and are great I love reading about how much they love theirsuits like they fall in love with them okay so what is it for obviously this isthe centerpiece of this but how do we start to make our assemblies so this isour centerpiece and there are two other pieces that we need we need a heatexchanger to reject the heat mhm and we need another heat exchanger to absorbheat one of those heat exchangers that's rejecting the heat is going to go fromrefrigerant which is a gas in this case to air okay and we'll have a fan blowingair over that the second heat exchanger will go from liquid refrigerant as isvaporizing to cool water and that water will then circulate through your coolshirt ah okay right so there'll be a heat exchanger between the right so itwould need like a big aluminum plate that's touching the water or somethinglike that something like that will actually use a stainless steel heatexchanger that will go directly from the boiling refrigerant into the water ohinto it oh okay and we'll tune the system a little bit so that the waterdoesn't freeze or you can also use alcohol instead of water and great Ihaven't money on that even colder ah yes let's do alcohol so let's see I lovethat idea aye aye sir purple will that work isopropyl works I actually tend touse alcohol with vodka oh yeah great yeah we'll send out for avodka there's plentiful in the mission to serve and hasten why vodkas great isbecause it's non-toxic depending on how much you drink since I don't drinkthat's fine so shall we gather the parts over herelet's gather the fire okay all right these are both versions of the samething these are two versions the same thing and we have a big huge changer andthen a smaller key exchanger now the high seats project uses this smallerheat exchanger mhm and the high seas project is not so noise sensitive mm-hmmwe can have a little bit more noise generated and it doesn't cause a problemfor you though I think we want to go with a bigger heat exchanger okay and aquieter fan so the weight is not much different no there's fairly negligibleso sure yeah listen I can accommodate great something this large and thenwe're also gonna take two other heat exchangers over the table we'll talkabout these two as well because they're pretty neat technologiesAspen compressor a US company made in US that has just some really niftytechnology and it's hard to get refrigeration components in lowquantities most of these companies they don't sell to consumers or individualsnow he did not sell the consumers and individuals but if you go to an HVACstore you're not gonna find compressors like this you're not gonna find composedlike this right they sell repair parts of those HVAC stores so it's difficultto build the supply chain knowledge to know where to get this stuff these twocomponents are US made this is a heat exchanger from the company called allcoil which is in New York Pennsylvania and they make small quantity componentsgreat for specialty applications like what we're doing if I was to go to acompany say in China or Thailand that makes these for refrigerators or airconditioners the minimum orders gonna be 10, 000 units okay answer the phone foryou you have to send them a check for 10, 000 units and then then they'll talkright all coils great because you can order one oh and to be clear about thatstructure of this this is just a wide flat tube yeah and throughwhich the material passes and all of this are simply surface area thataluminum meant to shed the heat correct okaythat is super cool so this is called a micro channel heat exchanger and it haslittle micro channels that run along the length of each of these serpentines sothere's maybe a hundred channels from top to bottom here and we push gas inthis end the gas flows through and because we're pulling so much heat outthe gas is a liquid by the time incorrect the other side erects and it'sfreaking cool that is really really nifty and see all the way through thisthing and the larger the heat exchanger for a given amount of gas that we'retrying to cool the more surface area we have to call that gas and the less airthat we need to blow over the any given surface Scott it so the bulk air flowcould be the same but if the bigger fan I make for a given amount of air flowmm-hmm the slower and quieter the fan can get so if I have a really tiny fanand I'm blowing say Exner of CFM x / CFM I have high velocity it was loud rightright if I double the size I quadruple that surface area and I can reduce thevelocity proportionally right and then also have have quieter fan bladesbecause they're not slicing through the air what is okayso the bigger fan means that it's quieter right okay it also means that wecan really crank your system up if you want if you're like I need 800 watts ofcooling good things to know about the body as we're standing here right nowwe're not being very active we're dissipating about 100 watts ofheat I'm talking about okay hot light bulb those incandescent light bulbs Iguess the kids might not know about those yeah kids yeah the brightest lightbulbs 100 watts and it got really hot it got really hot so and that's what we'rethat's we're putting out kind of the same amount of heat over our entire ourentire bodies okay so it's a room temperature thiscompressor can pull out a couple thousand watts really you crank it up tothe max Wow so we're not going to need to do that to keep you cold but if youdecide that you want to sprint through comic-con's doesn't just crank the knobup and amazing amazing okay I'm just really psyched about so we've got aconfessor we got the heat exchanger that we're gonna get rid of the heat with andwe're gonna position this above the compressor okay we have a heat exchangerthat we're gonna boil the refrigerant in and I brought two options here and Ithink we're gonna use the larger option for you okay for several reasons one isthis is a called a brace plate heat exchanger and it's stainless steel weput refrigerant in these tubes those tubes and water through those tubes Idon't know don't fret but they exchange heat between the twoyep freakin cool and we can attach some fittings to this end which less blowwater through here and then into your suit WowMPT it's actually a not it's a British straight pipe thread and the reason whyBruce straight pipe threads are used for these is instead of a taper instead ofNPT okay so the taper thread is basically a compression stretchingfiction fit so you're literally stretching the metal and tighten thatdown and that's great except once you've got that preload you have to maintainthe preload or else the fitting fails and if your heating and cooling andheating and cooling and doing this ignition putting a lot of movement andyes and it's gonna work itself away it works itself loose and no matter howmuch the thread lock you put in that eventually will work itself loose soamazing I a made in my book when I was writing the chapter on glue that was oneof the hardest parts to write list you've got to think about what the gluesgonna go through yes and it's expanding and cooling that means it's gonna workitself away from this or that material if it's not the same material propertyexactly exactly so we use a straight thread and then theseal is created with a gasket no and that gasket just provides a little bitof preload and if the gasket ever you know maybe ten years from now the rubberhardens you unscrew it another one pop another one okay good to go all right Ilike this this is great so we hook these components up with some copper tube andthere one piece that's missing here we use the compressor to put work into thesystem right and then we exchange heat with this first heat exchanger yeah nowwe have to create some way to reduce the pressure so we keep the high pressureside high pressure we have to drop the pressure so that the refrigerant willboil right so we have liquid coming out of the bottom of this heat exchanger wewant to blow that liquid off and if you think about water in space the vacuum ofspace mmm is a loan of pressure that water will just boil off and as it doesit will absorb heat right this is the same thing we have a pressure low enoughthat this substance here which is our refrigerant mm-hmm will boil at thepressures on the low-pressure side of the system and this is a new kind ofrefrigerant that doesn't add to the ozone hole that's correctly closing likefreon used yep okay so this was developed as a replacement to freon inthe early 90s and does not destroy the ozone layer and not many people know butamong human beings many crimes the ozone hole is about to become an ex humancried like it's closed it's been closing steadily over the past nine years asindustry has responded yeah and very occasionally we see blips of risingrising your factories in China I think there's a recent story I heard that andthe Amazon and fires also help you out a tribute to the yeah so but we're so howdo we create that low pressure system so we tried that low pressure system withthe copper tubing equivalent of a resistor it's basically just a flowresistance that you can either use a small nozzle to create that pressuredrop yeah so you have a high pressure behind a nozzle you have low pressure infront of the nozzle yeah or we can use a long length of copper tubing so Oh anylength of pipe will create resistance and friction as the fluid flows throughit and it literally operates exactly like a resistor which does it withelectrons but does it with fluid exactly so the whole analogy of electrons towater pressure is actually still works it's still tracks yeah yeah that's greatthe copper tubing will use the length is going to create the pressure drop and wecan change that length that change the pressure drop and that's gonna have aneffect on the temperatures that you'll feel great so we're gonna pick somethingthat will give us a little bit below freezing for you at a high speed settingwith compressor terrific I'm gonna action getting us some vodka in the shopand I also have a new cool shirt that's actually a full body perfect suit andthat's the one I want to try I bought it's actually a 1980s BritishRAF cool suit for high-altitude fliers but that tubing all feels like it's goodit's still like extant and flexible excellent excellentawesome um well you got two that I'm gonna get those broad right right that'sexcellent and the tubing is perfect it's feel its weight hunger than I thought ohyeah yeah that's great so there's some big ones that run out I haven'tpressurized this but my cursory inspection led me to believe that it isin pretty good shape yeah this is expensive and the tubing goes you knowit's funny cuz this is the other question I have is there must beoptimizations you can make for flat tubing that has a greater skin contactyes and thus a better heat exchange so there there is the funny thing there isa discovery in the early 2000s from some researchers at StanfordDennis gran being one of them that you get the best heat exchange through theparts of your body that don't have hair on them so your palms soles of your feetyour face and you can do more heat exchange through those surfaces than byputting a suit around your whole body oh my god but I think putting the suit onyour whole body creates perceived comfort in addition to actual heatexchange and right and that's really important too there couple water pumpoptions oh look at that and this is gotta have a water tank haha ha ha that's the oh that's the size that you need it doesn't need to bebigger don't need to be bigger than that so this is the exact size that's in thethe high seas suit Wow Wow Wow and this is a different one this is a differentone that's a tank and pump built-in ooh that's kind of sexy to know I figuredyou might appreciate that oh my gosh this is amazingsince it as an engineer I appreciate less complexity equals more reliabilityso I'm inclined to go with the pump reservoir combo what do you think weshould try them both out the nice thing is we can build the refrigerationcircuit right and have that be a standalone thing and then you can andthen play around with the options okay long so great I have the in the CADright there there's a little pump that is right here mm-hmmthis is this amazing British $200 really high-quality high-pressure super quietwater pump and I didn't get a chance to grab it because I was running late tothe airport Oh we'll just use the one that I shipped this is great this lookslike a kind of almost like a bait pen like yeah we need some LEDs in there yesokay so what is the first step for assembly it's really the first step forassembly is we want to set the components up so we've got two heatexchangers that we're gonna need to basically position and then brace somecopper tubing into okay and if we go with the drawings that I've made I thinkthe ideal setup is going to be something along the lines of this okay so do youneed me to make a bracket so we can make a bracket or I think the the processthat usually is to do this is positioning the parts and then figuringout what the copper tubing run should be and we've got a the high seas model thatwe're starting with but we're gonna use a different heat exchangeI use with high seas so the high seas system used this heat exchanger which Ihaven't talked about yet okay I talked about that for a second okaywhat's different between this heat exchanger in this one it's a m– thingtwo different channels for different liquid right that are kept opposed toeach other yes yep and this heat exchanger is a stack of steel plateswith some ridges on them and the steel plates are pressed together put in afurnace and then the furnace raises like surface mount electronics almost exactlyokay and the that stack you can see these these kind of channel formedchannels and the the way this bottom plate is a pan all the rest of theseplates have that same pan feature okay so you stock all the highs up mm-hmm andthe pans alternate refrigerant water refrigerant water for the water thebrazing process is is you could do this with a torch yeah but doing it in afurnace gives you good uniformity this heat exchanger is also steel plates butthese are flat steel plates with and they didn't have the channel have beenetched so those plates are thin enough that we can use actually processes andthis is then vacuum furnace bonded and the bonding process involves heating upyou put it a dissimilar metal bracket around it and that similar bracket whenyou heat this the steel expands more than the bracket does so as the steel isexpanding the bracket creates a compressive force that diffusion bondsthe layers of steel together good god with with Wowso we we can etch micro channels in using photo lithography processes thatare super precise we get a much smaller more compact unit that isn't doesn'tquite have the capacity of this but you can see is that's an impressive thesmall thing heat exchanger is something that can cool down a human body that isis rated at 800 watts of cooling some believe this is rated about 1.
2kilowatts of cooling and and this is so efficient becauseyou can get high amounts of precision in the etching process and that's a lot offlow through it even though it's really tight a lot of float a lot of surfacearea for exchange right right right the surface area is everything surface areais everything and the difference in price of these is also pretty funnythis is maybe 40 $50 get them made in a factory overseas this is about $400 so10x difference in costs okay I see super super cool technology from one-offprojects those those aren't crazy price points but for any business venture thatis variant difference you really have to have a need for using something thatsize we're going to use this mostly because we can put threaded fittings onright and make it really easy to interface directly with your suit andpump and when you're holding this up here and this goes with this I wouldlove to know if these pipes can be there while I have a lot of room for to put inlet's say fake place for a space suit this space will be a premium so I'd loveto keep that dimension this X dimension as narrow as possible assume we can cutthese a little bit tighter we're not gonna cut them we're gonna bend thoughokay great so I've got some metal benders too and some flames tools who weneed those and Bend you know the copper tubes around soit'll create a nice flat profile okay we'll keep everything in a line and thatway we can get our refrigerant out to our heat exchanger so we go out of thecompressor and we go up to the top to of the heat exchanger that way notice thegas works its way back and forth and gets to condense down to liquid theliquid drops to the bottom and then the bottom comes out and then goes to thebottom of this heat exchanger okay where we boil up so we end up with a gas atthe top okay and then alright so there's a direction to this there is a directionokay yeah and then to mount this to this I'm assuming we need a little bit ofsome bracket äj– is that correct right it's will be good we can zip tieup but brackets are gonna be better okay ultimately I have endless numbers ofspacers and our little nuts and bolts and even allthread should be needed after we get everything positioned the way we wantwe'll mount it on a fixture great 80/20 a piece of wood just so that we canbraise it yeah once it's braised it'll hold the stuff together then we can makesure to measure and create a bracket that holds everything in to your suitfabulous don't put any strain on the join them to copper joint becausealuminum copper joints they're delicate they're very delicate oh that's lovelyyeah it's it's soft and I can guarantee that I'm not overloading the joint rightright right notice that it's it stays straight as itcomes out of here right I got most of the bend and that's important because wedidn't stress exactly at all exactly because if we lose these connectionsbrazing copper to aluminum is one of the hardest things I've ever tried to do Iwant to think about it don't even want to think about it succeeded betterpeople than me it conveys this John all right I'm gonna up a tube that's gonnacome out of the compressor and it's gonna need to get into here right so ifI flipped like that and then it comes in the top I can come out and beyond up inthe top okay that seems great so that makes that easy okay and then the tubethat comes out of the bottom is going to go into our expansion valve so we'regonna have something like this come in here we'll have a coil of some of thisand like I said the length will determine the temperature thatdetermines to the temperature are the length of this tube which gives us thepressure drop okay the speed of the compressor which tells us how much gaswe're moving how much mass of past a certain point right and then the amountof refrigerant that we have in the system so we want to balance those threethings and we've got some tools to do that okay how do we braise this to thisdoes that get braised or is it a pressure fence that's gonna be braisedwe're gonna braise all this stuff together so do we need to machine somespecific copper little couplers yeah you know we could machine them or we couldjust take a pair of pliers and crimp the soft copper tubing down around this ohreally yeah and that's do and then you just fill some amazing material you knowthat I do it just want you to see the coolthat day that I did invest in full retail rack or both of these but I'm allabout the simplest possible fusion doesn't know that I have this is good toknow one of the funny things about this tubing you saw how easy it was for me tobend yeah by hand yes this there are two styles of copper tubing forrefrigeration there's drawn tube and then there's aneel tube right the drawn tube is pretty rigid right because it's beenmechanically drawn yeah it means it's work hard work hardened yeah the annealtube after you draw it even baked so and the steel is release all of thosetensions of the crystals from inside yes and it's super bendable and it's reallyfun to work with so you don't need College to talk engineering we shouldnot mention how many degrees I have I have zero three I an honorary degreeswhich are worth just as they're worth nothing actually did believe it or not II think that the out of school education for me has been so much more informed somy background is I have a mechanical engineeringright right right this is all thermodynamics and what's really reallyfun about this is yeah I'll make fun of my education it's a fantastic educationand I it is certainly extremely well but when I took thermodynamics in college Icouldn't tell you what all these parts were how they worked what they did I canjust tell you the math behind what what they're supposed to be doing right rightand the gap between that theoretical knowledge and then understanding notjust like why do we have a capillary tube right but what these parts are howyou put them together that gap was pretty big in closing that gap not onlydid I take that theoretical knowledge and then the practical knowledge andrigid but it gave me a very deep appreciation for how these systems workand how you optimize them ago I behave and I think that's something specialthat we really need to get more engineers learning the practical sidesthey see that and get more of the technicians understanding a little bitmore of the science on Mythbusters we frequently had trouble when we call upone of the world's experts in the field we were trying to explicatebecause they'd be so much of an expert at the one thing they knew but theycouldn't discuss with us how it crossed correlated to this other part of thestore right and nothing exists within its own frame it's all reaching out todeal with other frames and so we found the polymaths the people with more wideranges of experience much more able to talk to speak to and adjust betweenmultiple fields it's it's amazing the contexts that connect something likethis and how much knowledge of this context really really helps put thosepieces together like okay I see a compressor I know what it does and thenI know the physics of what's happening so I understand what goes on inside theexchanger and what changes when I speed the compressor up or slow it down orchange the diameter of the capillary tube or change refrigerants from say our134a which is freon it's not only every change affects multiple other systemsyeah and so it's not just a simple of move this and this happens it's allthese cascading if I can change the chemistry of the refrigerants and thatchanges everything else in this is Wow and understanding what those effects areor change the speed of the fan and what's gonna happen how much liquidrefrigerant do I have left over when the speed of the fan goes up amazing allthose things are connected well I figure it doesn't matter how far it goes in noyeah okay so then the bend comes about here yeah you could start bending thereand because we're just gonna want to clear the fan and I'll stay in line withthe IC I kind of want to be in line with that valve at the bottom yep oh it's this is the best stuff to workwith so then once we have that and I think I can actually come in eventighter yep and then this comes around here and comes that way wow it lookslike I actually cut it I think you have excited it's just about the perfect sizeWow because if you didn't we could fudge ita little bit because we're gonna do the same thing we're gonna insert this intothe mouth of the compressor since that's a quarter-inchdon't pull that out yet okay so the reason why this has the plugs in it isthat the compressor has a oil that's a Palio ether oil mm-hmm andthat oil absorbs moisture and as it absorbs moisture it creates an acid andthat acid over time will eat away at the insides of the components so we don'twant to so I'm gonna cut this down by half inch cuz we don't need more thanthat just a little bit far oh yeah yeah yeah and how much copper to to stealbrazing experience you have hmm some oh I'll do the first one I'll tell you knowthe stuff that I use for everything is stay bright silver solder so we I'llgrab stay still 56 over 60 still 56 which is a high silver contentphosphorous bronze brazing rod the high silver is we always use it in specialeffects cuz it's strong it's really strong and it's just about the onlyreally sensible way to create the copper to stainless steel bond and I uh I wasdoing it to UM what did i buy oh those stainless steelchrome doesn't actually desert brass and then chromed balls and I'm able to tobraise brass to them nice right through the chrome yeah that's really nice thatis pretty awesome so we'll do that to copper to stainless here and so we'vegot that connection I think that's gonna look nice yeah we the bottom of this isgoing to come out and we're going to go into the capillary tube and willbasically spiral this down and come into the bottom the heat exchanger here sowe're gonna take a little quarter inch pipe and make a straight stub to comeout and we'll crimp that stub will crimp this into here all right will crimp isstub into here so we're kind of what we're doing right now is setting up allthe brazing we're going to exactly if we don't do a great job cleaning thecopper tubing those little copper filings will flow through the system andend up in the compressor we don't want that to happen so we use this filterdryer which has a little filter on the inside and I've have these made at afactory custom-built for me so that it's got the right diameter to slip right onthere and for our capillary tube to slip right in there if we didn't have thatthen we'd have to create fittings that make all these things fit together sothis will make it a lot easier perfect and that's really cleaned out with athree sixteenths reamer excellent so this atom is I brought a couple filterdrives cuz I didn't remember which size we're going to need but this has one theperfect fitting I'll just slip right on there and we're gonna slip that heresame thing now we're gonna have a maybe 30 to 32 inches of tube coiled that willgo from this point here down to this point here okay and the really nicething about that bender that you have is you can do clean hundred and eightydegrees yes that's nice yeah okay so then so then we're just gonna do180 full Bend yep from from right about here yep I'm no copper dust in there so perfectlook at that right there okay so then that goes there yep sothat's that's it those are the P really yeah oh wait but then there's this itgoes to do yeah so the rule like said we'll have this this one's gonna go hereyep and then the coil is gonna come out see how this is so nicely sized if itreally really sexy the only thing that we're gonna do that's gonna be tricky isand by tricky I mean slick and also difficult great is we need a fitting tobe able to add refrigerant and a fitting so that we can measure the performanceof the system okay so does that mean we need a little T of copper you know wecould use it T of copper but what I've found is that we can cheat a little bitand we can drill a hole into the side of the copper th and we're gonna braisethis in okay what that ends up looking likeso this joint mm-hmm is kind of uh oh that's crazyyeah didn't do that I did this way closer to the copper yeah we're notgonna do it that close because I think I probably got lucky there there's no reason to expect accuracyfrom drilled holes on them Fe so having Center drilled that we have a reallyclean hole now that's lovely get a nice fit there oh yeah oh good onething it's really important to always remember to take your Schrader cores outbefore brazing yes because the o-rings always that makes things bad thedecision as always we can fuck the flux this we're not really if we're doingcopper to copper and it's fresh clean copper like this flux is optionaloh I didn't realize that got a little bit of an orange tail Iwant to try to get that to be a little bit okay that's pretty good yeah it's a nicelittle it's that will keep that joint clean it's really important to flex this jointbecause we've got the dissimilar metals coming together and the flux is what'sgoing to allow the brazing material to flow in between the metals effectivelyso we want to get good coverage on the surfaces and it's going to make all thedifference so that should fill that material upclean that up to make sure we get some good flux coverage again and then we'regonna heat this sucker up secret here is we want to heat up thecopper first and the stainless steel last how's it going you here just forthat part so this is the copper to stainless brazing and this is a toughthing yes this is the tough thing so we hit up the copper because the copperconducts heat a lot battery well and it's just gonna pull the heat I giveaway and I'm just gonna keep stroking the copper whistle until it flows andthen I grinding again I just get the stainless a little bit make sure we getgood coverage dude and we got a really nice clean joint that's awesome you cansee how uniform that so you're actually feeding nitrogen in here while you'redoing it yep any we shut that down now you can examine cuz I actually uh fillsus with nitrogenous abstentions everything air Oh nitrogen that oftenjust sits there very cool so that's one joint and the only thing I'm gonna do isit's right here now we've made that joint I want to make sure that we flowthrough here yeah because if I screwed up that's never good so we should getthe puffs there we go Oh cuz you can see it step out there yeah if I fed too muchrolling the target I'll clog it up I've done that once yeah I've got about ahundred fifty systems and it's like let's never do that again and so nowyou're gonna do the same thing again with this one yeah alright it's alwaysterrifying brazing stuff there other stuff that's been braised yeah yepfortunately oh I see you needed the goggles that daythat shielding yeah I mean this is it's it's really not that hot of a flame butya know it's good practice because the oxy rig will make you blind for a dayyeah pay attention all right that looks good so should be reallyuniform some of that is definitely flux it's always good to clean the flux offand make sure that that's do you need a certificate to do that you need thehydro oxygen yeah okay I think I've got some yeah so that's that's the stainlessto copper and we can take advantage of these fittings once they're braised into fill the system with nitrogen amazing so we're gonna have this sitting herewe'll pop that into the and it's slightly long in case yeah well Iinstead of cutting out I just bend it up a little bit cuz it's it's so mucheasier right right right once we're yeah you should roll it yeahwe can roll it we can we can work with this straight piece here mm-hmmso the we're at that point where we can look at the last couple steps I alwaysdo the compressor last partly because the compressor has the oil in it butalso because we can get everything else set up and if anything has to gettweaked we can tweak it and then the compress will be the last joint to makeso there the next joint we can do if you want rest that tube on top of thecompressor you know the next joint will do is the coming out of here and thengoing down into here let me just dunk it in a glass of water right exactly is ithygroscopic we'll pull water back into the holes yeah okay so we want to get itup quickly so we'll hook it up while we're still pretty warm and I'm doingall the brazing with the high silver content material just because we canit'll look pretty when there's just a little in the back yeah see so I'm justgonna make sure it's got coverage good it's like that puppy on here oh and thenwe want to measure out I could do these separately but we'll do at the same timeokay guys stay selves why the heck not Oh use that as the SAS nice how can I dothis part that looks really fun there's this kind of thing thank you for lettingme play one part for inches off the end we can split an unsupported supersoftthat's perfect oh whoops oh yeah sorry I shouldprobably close up first there you go excellent so we're gonna stick this inhere mm-hmm get a little scotch brite and then oncewe get everything set up the last thing we'll do is unspool it insert it inthere and close everything up I guess and just a straight up tubefilled with desiccant right yep and there's a little mechanical filterstrainer filter on it as well so you're not doing anything but just improvingthe desk it by getting it hot right right nice wedding give that good weddingmake sure there's lots of extra in there so I try to avoid getting you that's allright I can take it all right and then one of the things again I'll do is makesure that I've got good flow and I didn't plug in a hole so I'm gonna holdmy finger over that you know and then ya feel that oh yeah oh nice yeah carefulabout breathing in that nitrogen yeah are you kidding just an asphyxiant rightthat's exactly exactly it so we're pretty good shape the final three jointsto do I think we'll do the compressor now and then the last one will do isthis okay so so now we actually want to pop out the plugs and the faster we doyeah this one the better works three perfect now we hit it okay just a littlebit cleaning there then this one will take a little sneakit around like that but more maybe we'll stick it underneath like that and thatgoes that'll go there so you want to put such bright that these are the other twotricky joints because heating up a painted compressor right with oil in ityes it's always it's fun and ok that's the steepest that one's going yeah soagain we could just do regular because it's so clean because it's clean andcopper to copper but it I think you'll enjoy the shiny silver finish along thebraze joints so now there's a fun bit where we canput pressure through here we should get something out of here and they'll put myfinger on here yeah and then that will pressure right here yepsee here that the little click in the compressor I'm hearing something leakingsomewhere yeah that leak is right here oh that's that yep that's put my fingerhere oh this tells me we have a complete circuit wait so yeah that's awesomewe've pressurized we've got pressure all the way back through our evaporator thecold side yeah we've got pressure through the compressor we're actuallypushing nitrogen through the compressor through this heat exchanger through thefilter dryer and then out the capillary tube which we will then hook up to herethis is the last braze connection we have to make and then you have a fullycompleted circuit we'll put that in a bucket of water yep will pressurize withnitrogen make sure there are no bubbles okay and then we know I've we have asealed system we can pull vacuum on it so incredible and then this is where thewater circulates yeah this is the business end that's the business end soelectricity in here cold out of here at this point everything is ready to go soall we got to do is bend this down and start it in here and use the pipecleaner also to make you stiff being out any authorization since we've done allthe brazing under dry nitrogen yeah it keeps the dryness make sure that wedon't get any water in the system any water in the oil the nitrogen part isnice because we can get it instantly it prevents an oxidation inside during thebraze it prevents the heat oxidation from causing like this kind of flake canyou see on the outside oh that would end up that comes amazing the flow rightthat ends up inside right and that that material the oxidized copper just clogsthe oil and over time it might take ten years it might take one year but overtime if you got enough of it right it caused the system to fail unroll it likethis and then do a kind of a twisty twistyeah and ice have it come down like that exactly and then it just would sit likethat to me is kind of nice perfect that seems like cheating it isso I have got a little bit of motion so I know that I didn't crimp down on thetube itself so I just closed this off and if you look at the end you knowthere's enough of a gap there all I got to do is fill that with Ray's materialsand then we're good this guy this is pretty easy joint because there's not alot of copper here just on the end just like that nice amazing and fast that isdone we have a fully built system now should be all done with the brazing partand we're ready leak test oh it's time to leak test it's time to leak to usokay so now you need a bucket no we need a bucket of water all rightkid this is what happens when you ask a science communicator for a bucket thatshould yeah that should hold the whole thing I think we're gonna have a littledisplacement I may need to add a little on top I don't want to get any water inthe Schrader's because that water can right then potentially get entrained inthe system so I close these would have a nice gasket on the inside oh nice andtake use this one to fill so we take our nitrogen i nitrogen attached that we'vegot a Schrader's in now and we'll do a pressurized bubble leak test okaywhere oh why see will pressurize it and put it in to see if it's coming outanywhere so we're now at 200 psi of nitrogen may I not yell we do that it'sgot excited you good to get excited she's very important we're gonnadisconnect this line oh so now it's still under pressure so still underpressure we have because of the Schrader exactly and this is why having theSchrader's in number one I know that had a straighter and now because Ipressurized it let me do this and if that's coming out of that right now justcoming out of there yeah hmm interesting I don't think that's a leak in the heatexchanger a leak in the heat exchanger yeah that's a pinhole heat exchangerleak well all of my brains don't sit good do you want to try and braise thatone should try to braise that shut okay that looks gooddamn all right okay let's cross their fingers and hope thatwe do it's these are lost free fittings or Loas fittings amazing I was amazedwhen I found out you could do that by using hydraulic quick connects withpneumatic systems yeah yeah yep all right I just put it up to about 300 psiso okay really will we should see something immediately if I did a goodjob yes I've never done that before firsttime ever that Wow dude that was an awesome effect now I just want to makesure we get all of this underwater let me put this cap on first oh yeah thereyou go sorry thank you nope no worries thankyou perfect and I see no leaks coming from anywhere yeah amazing dudethat was that's you know nuts our day could have gone any which way in themaking or we're done by the end of the day that it's awesome so do we leavethat in there for a while yeah we're good we okay have a lottery system testdone now does leak test done you have a hermetically sealed system as we know ohmy god and the next two steps we'll pull out a vacuum to remove all the nitrogenokay and we will oh and then we fill it withthe thing we fill it with Bertrand we've got that so we'll pull vacuum to removethe night remove the nitrogen we will fill it with a little refrigerant hookup the electronics fill it with more refrigerant walls running and thenyou'll have a perfect system amazing inside my gauge set right now I've got aa very high vacuum that I've pulled over the weekend and we've hooked up a can ofautomotive our 1:34 which is the refrigerant we're gonna use for this andyou have to be certified yes plumb this is X so I have certified a universal EPAHVAC certification under normal circumstances we would use in any realHVAC work a 30 kilogram okay big bar a 15 kilogram tank right a big bottle inthe case of a system like this we're really only gonna put about 30 grams 40grams of refrigerant in okay so it doesn't make sense to have 15 kilogramswhen we only need 30 grams as an alternative this little tank ofrefrigerant here for automotive purposes is 340 grams so we'll end up using 20%of this bottle or instead of like 2% of a really big bottle that's awesomewe've had to make a little juryrigg connector together automotive bottle andthe automotive can tap through to our standard refrigeration fill line and webraised that in the other day the other time so I've purged any air out of myrefrigeration line and ready to fill this so we always fill the suction sidewhich means adding refrigerant to the blue line okay and to do that I'm gonnamake sure I always start off making sure my valves are closed this one I can haveopen because we're gonna add refrigerant here we've zeroed out our scale I wantto know how many grams we put in okay it's helpful to understand how thesystem is behaving and at this point is pretty simple weopen this up we know what's up and we're gonna squeeze the trigger to add morebread so we've now added a startingrefrigeration charge of let's see how many grams we've gots three whole gramsof refrigerant so we've got about three grams in a system the pressure has gonefrom high vacuum up to 55 psi and this is when we can start the compressorsince we no longer have the system under vacuum we have some minimal refrigerantcharge in the system we can spin the compressor and it can do some work oncewe get the compressor moving we'll continue to add refrigerant until we seea couple different values up here on here so I'm gonna grab two other clampsso we can watch the temperatures so this first clamp I'm putting on the suctionside of the compressor okay and what this is going to tell me this is reallyfundamental measurement we're gonna be boiling refrigerant off here and therefrigerants gonna come through this heat exchanger and as it's absorbingheat we can measure the temperature when it gets to here okay we're alsomeasuring the pressure at this point so at a given pressure we're gonna have agiven boiling points of given temperature for water water boils at 100degrees the gas that's the steam that's generated can be hotter than 100 degreesthe water itself right can never be hotter than 100 degrees Celsius 212Fahrenheit at sea level but we can change the pressure like if you go toColorado you're a higher elevation which means you can have a different boilingpoint in different temperature so we can modulate those boiling points oh Ichanging the amount of refrigerant in the system and changing the speed of thecompressor fascinating so look at them that can change overall how fast it cango through cooling cycles and how much it can cool and also how efficient thesystem is I never realized it was an adjustable set of values with it yes Ijust thought you put it under pressure and boiled it off and in thatchange you got cold but that's but your with part of it different pressuresyield right right right oh my god so we can adjust thosepressures and temperatures and we're gonna adjust them to make the systemreally efficient and also give you the right amount of cooling amazing so rightbecause there's an optimal relationship between the values exactly that'sexactly the case so okay gonna go ahead and make surethis is all ready and if you feel this actually no and you probably get alittle cold that should be cold mmm-hmm these cans are not the bestthese fittings leak a little bit so I see I want to make sure that we've keepour pressure up here and now we can basically spend the compressor now okaythis control board is ready to go but I'm gonna take a little shortcut herewhich is I don't know why I write to the compressor we can wire the right rightto the compressor I'm hoping that my software is still running on our littleArduino board but we're gonna plug in 24 volts hook up Larry turn this off roundsno go ahead I don't mind plugging things in whilethey're on it's all low voltage yeah nothing to be afraid of here all right so because that second we'llsee if that turns on and if it doesn't then we should wire directly in whoathere it goes so that was a great check system yeah that it was going through tomake sure it was finding everything it wanted to find exactly and now thecompressors running I'm gonna keep adding refrigerant okay and I'm gonnawatch these temperatures so this is the temperature that we're boiling at rightso I want the warm side of this to be warm enough that we can reject heat andthe cold side cold enough that we can absorb you tonight this is getting warmer excellent yeahit's definitely getting colder right down at the bottom here where the ohyeah boiling is taking place that's gonna be the coldest spot other thing wecan do is if you have a jumper I think we're gonna jump the 5 volts directly tothe speed setting so that I don't have to plug my Arduino in all right sneakthat in here there we go 77 a fan on here we can start to get rid ofsome of that heat okay oh yeah this is getting nice and hot onthe hot side okay so now you need a third um power supply before when we weren't taking heat awaythe cold side was cold but it was not as cold as is now now we're getting rid ofthat heat the cold side is extremely cold to the point where we've got alayer of ice forming on all these – once we hook add them up we will get a loadso we'll start taking Adams heat away into this system and then when we crankit back up to full speed Adam will get cold quickly outlet into the top one because we wantto go okay flow we want to have right coldrefrigerant going up and we want to have the water going down that way you'regonna get the most effective cooling fastest and then it comes out of me into intoyes into there yeah it's pumping out a lot isn't it oh that seems like right weshould let's crank it up we're going it that slow speed here so you crank thatfan and we're gonna go yeah I was thinking it didn't feel like it wasgetting any colder but now it is I mean I'm definitely feeling cooling all overI loved it this 1975 Royal Air Force cool suits still totally functional they're fast we can go before you feelin it like the moment you did that I'm feeling a difference yeah that seems tobe one of the limiting factors and how cold we can get yep yeah I can feel theconspirators we're circulating so we definitely need a more powerful pumpyeah dude check me out I'm getting cold thisis the most elaborate way to get cold in most the United States right now if youjust walk outside there's also helping it sink in howincredible it is that NASA built us all into their space students writesomething fully everything here is in a self-contained spacesuit along withoxygen and other stuff going on and other telemetryoh yeah again I always understood how the system worked but seeing its levelof complexity is kind of amazing in the vacuum of space dealing with temperatureis really tricky because you can't conduct temperature away by by havingair that's cold or hot right right you've got solar radiation that'sbringing a lot of energy onto people and then you're giving away photons out inthe space so there's these trade-offs of of heat flux this that NASA had a systemthat kept kept astronauts cool by actually boiling off a gas and dissipatea liquid in space and basically just vaporizing it and as you do that you canyou can have a lot of phase changes happening here right it's changedabsorbs energy absorbs heat and tah-dah you're managing temperature now I feellike I'm standing outside oh yeah great day I'm starting to get real cold it isactually I think we're hitting some good at some point you can look at thethermal image oh yeah that's awesome yeah you can see the lines on your bodywhere the FLIR is picking up all the cold tubes that's spectacular I thinkthat's what I would call a successful test of the mini refrigerator that Kippdesigned and we built here because it has me freezing and I want to say cut sowe can wrap it I can get on some normal speed clothes so cut really noticeable it's moving I meanit's moving to heat yeah man and if we crank up the the pump yeah you're gonnathat's pretty awesome.
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