Ultra low-temperature cascade refrigeration system repair

[@dedkeny]

I love the way you abruptly end your older videos

[@WorldConkerer2012]

I wish you were my uncle. You do so much cool stuff!

[@peterthinks]

Very interesting! If you ever want it colder try natural gas. It boils at -163 and is very easy to get. It's an amazing refrigerant. No it won't explode.

[@kayakMike1000]

Yep. I think refrigerant grade methane is R-50 or so...

[@TheMinecraftACMan]

@@kayakMike1000 Spot on lol

[@pinkdispatcher]

As usual, absolutely fascinating. Thanks you so much. The combination of hands-on stuff with solid scientific background is quite unique.

[@edgeeffect]

Have you ever considered that you might not have just the best equipped home lab on KZbin.... but maybe the best equipped home lab on Earth?!!

[@prabhnoorkainth1520]

What a coincidence! Just 5 mins ago I was reading the manual of a cryogenic vacuum pump that we are fixing at the lab and then I saw your video which is actually quite relevant to what I'm doing.

[@mikeselectricstuff]

Was the issue with getting the etyhlene one of finding it at all, or finding someone who would sell a small amount at a sensible price?

[@AppliedScience]

Finding the gas for sale at any price was challenging. All refrigeration shops require their customers to have an EPA license, otherwise they just hang up the phone. Local welding shops all looked at me like I was nuts. Some told me that I should stop making drugs with the gas. Agricultural ethylene isn't usually pure enough, and is usually sold as an on-site service. One gas supplier agreed to sell it, but wouldn't allow me to pick it up from them, and also refused to deliver it to my house. A true wild goose chase!

[@cheerdiver]

Applied Science This is what I hate about the "corporate system", they have regulated the individual out of most tech markets. I tried to get a form of bacteria for a ABE fermentation (en.wikipedia.org/wiki/Clostridium_acetobutylicum), yet I am not a corporation, so they wouldn't even consider selling me a sample. This bacteria dies when exposed to oxygen, and is considered to have the same "health hazard" as common baking yeast sold on super market shelves. Purpose of experiment was to make butanol, a DIRECT replacement for gasoline. It doesn't take a Disney imagination to know why these restrictions are in place.

[@mrpeanutguy4719]

Applied Science So, where'd you end up getting the ethylene from in the end?

[@AppliedScience]

mrpeanutguy4719 I'd like to tell everyone, but I'm afraid that my source will dry up if I do, and I want to get more exotic gasses from this source.

[@NickMoore]

Applied Science Very cool (cryogenic even), that should give you more throughput than the nested bowls. I have been trying for months to get a new high speed camera imported to Canada and have been running into the same kinds of nonsence. The manucature will not export, ship to re-mailing services or sell to me in person if I were to show up at their office being an individual from out of country. "Civilian science" has taken a big hit in the last decade.

[@elmajiko420]

These cold traps are fun to rebuild. The piercing valve definitely caused the problem. The best thing on these system is to pinch off the lines and remove the Schaeder valve completely

[@mph8759]

Great video. I used to build these as computer coolers as a hobby over 10 years ago, that was fun! Looking at your 2-stage schematic, it seems that you placed the oil separator in the 2nd stage after the evaporator. If I recall correctly this would usually have been placed prior to the 2nd stage condenser as you want to separate the liquid oil from the gaseous refrigerant using gravity, in order to prevent the oil from clogging in your capillary tube.

[@mph8759]

P.S. you can get Ethylene and other technical gases from firms such as Linde, Air Liquide and here in Austria from Messer Griesheim.

[@mrclucker1969]

Nice compact system - well done on the repair - and to think it was nearly scrapped due to a leak!!

[@A1Skeptic]

Thanks for the great video. That looks like a lot of fun to experiment with. A Cloud Chamber you could turn on with the flip of a switch would be nice. You might also try reaching liquid nitrogen temperature by tinkering up a third stage inside the cold chamber and liquefying air. Actually I think you can make liquid nitrogen in the neg. 100 degree cold chamber you now own, by compressing air, cooling it to 100 below zero then decompressing it to cool it further. I want one! :-)

[@faxezu]

Do you ever thought about a room tour? I think it would be awesome to see your complete Workshop.

[@RimstarOrg]

I recall seeing his workshop tour video. You might have to go back a year or two through his videos to find it.

[@faxezu]

RimstarOrg I will search for it, but a update would be nice, too :D

[@gouthamkumar1750]

and there I was thinking to build my own helium cryo cooler and this helped me a lot....made the whole thing simple really thank you for this wonderful video

[@kenwolfe6093]

Heck I haven't played with r-503 since the 70's I remember the small cylinder I carried in my service truck was $500 back then. Oh, and on warm days I could hear the liquid sizzling in the cylinder as it sloshed around while I was driving. You still might be able to get it, but it's gotta be through the roof cost wise. This video brought back memories of ultra low temp systems that all used exotic gasses like ethane, with a touch of propane to carry the oil around the system to keep the compressor lubricated.

[@dan110024]

Wow. I can't believe that line tap was left on there. It must have been a Friday afternoon on Christmas eve for a tech to leave that there. Standard course of action is to crimp the tube (and leave the crimps locked down), cut the tube with some pliers or big side cutters between the crimp and the tap, and quickly solder the end. This is still possible when there is flammable refrigerant in the system. Just work quick and the torch/flame effect from the refrigerant is minimal.

[@RimstarOrg]

Interesting video as always, Ben. Reminds me I should look at the cooling side of the water cooler I salvaged. Might be something useful there.

[@TBizzell68]

At the end I thought you were about to submerge your fingers in -102C alcohol, but I knew better. Good work!

[@kyleberry3299]

Very interesting. I wouldnt mind seeing more about this kind of tech. In my industry we use freezers capable of -185C and ive often wondered how they got to such low temps

[@DaniloDetoner]

Olá, pode me informar o modelo?

[@Kashtanultra]

Nice video! R13B1 - most cold refrigerant im see ever in first stage. -57.5C on 1 bar. Impressive.

[@Arnthorg]

You can affect the pressure in a system by altering the amount of refrigerant in it. You can also get the vampire valves to seal if you don't crank the needle down all the way when you puncture the pipe. When you're done with the system you just crank the needle down until it seals where the needle functions as a piston and the pipe a valve seat. It's essentially a small needle valve.

[@bam1314]

The fluid the manufacturer uses is not alcohol but a silicone based oil. I think if you measure the temperature of the liquid you will find it not as cold as it is showing on the display. They put the thermocouple on the inlet to the evaporator on those cold traps and lie about actual temperature. Great job by the way for someone with no knowledge of cascade systems. The boss repairs these and ultralow freezers for a living.

[@bengr71]

Thanks for another great video. After watching the video showing you have access to, and some proficiency with a TIG machine, I thought you would have HEli-brazed/ TIG-Bronzed the refrigerant tubing connections. If you haven't yet worked with it, it may be something you'd like to become familiar with. Silicon bronze can be very useful for joining copper as well as dissimilar metals. It is pretty easy to work with, doesn't require the temperature for welding, so may provide some advantages related to distortion or working in close proximity to heat sensitive components and the strength is typically far greater than gas brazing filler.

[@ZeroPointAlpha]

+beng Typically with refrigeration systems, we use an alloy of silver and copper with a trace amount of phosphorous for flux, which contains anywhere between 30% (expensive stuff but flows into the joints really well!) to 15% silver.

[@250kent]

Thats so cool. Here is a task for you add a third refrigeration circuit and take the temperature further down. I had a chance to work on 3 refrigeration cascade system.

[@CherkasovN]

Hi Ben, Don't you think that it can be interesting to apply your ethelene to facilitate ripening of fruits? You can make a timelapse video of ripening of various fruits in air, ethylene (50%) and high-pressure ethylene. Thanks

[@richardbarber4444]

No question. Depending on whether you want to ripen table top fruit or controlled atmosphere stored fruit. I use bananas, prolific ethylene producers, to ripen other table top/bowl fruit.

[@jakeberge6914]

I work on Environmental testing chambers/ cascade refrigeration every day. Found this very interesting.

[@nattsurfaren]

I really really love this video. I have always been curious about how a cooling system works and especially making it ultra cool.

[@nattsurfaren]

I know there is something called a peltier cooler. I have heard that you can get to very low temperature with that if the heat produced by it can be moved away quickly. Can you reach -100c with a peltier cell?

[@AureliusR]

nattsurfaren Peltier elements are heat pumps, meaning if you have somewhere to move the heat to, the opposite side will just get colder and colder (to a reasonable limit). The reverse is true as well, if you can dissipate the cold, the hot side will get hotter and hotter.

[@elmajiko420]

There freezers that get below 150°C

[@张鑫-k2k]

what freezer? can you tell me, i can make -135 freezer

[@rich1051414]

1:15 Excellent explanation! I remember as a child it taking me much much longer to grasp this concept yet you made it sound simple :)

[@davidwilkie9551]

Manual-mechanical manipulation of the e-Pi-i sync-duration universal temporal resonance bonding. This is the best Equipment.

[@HB-et5iv]

Just a note: You can not get the low side's pressure "arbitrarily" low, i.e. you cannot go below 0 Bar/perfect vacuum. And even at absolutely 0 pressure, any refrigerant will still have its specific boiling point (way) above 0 Kelvins, and cannot refrigerate to below this boiling point.

[@rahulbindhu]

It's a dream to have a workshop like yours

[@markbell9742]

Great bit of kit for an experimental lab. Cheers, Mark

[@TheStraycat74]

I'd love to see the freeze dryer you could make with that thing!

[@dan110024]

I like your reasoning for choosing a 100psi charge pressure. Lol. Although capillary systems do require a critical charge. Unlike thermal expansion valves which can regulate the refrigerant flow and the excess refrigerant is kept in a liquid receiver. Sounds like you got lucky and it worked for you though!

[@lexbreijs8792]

was looking if anybidy knows about subcool and superheat here, congratz

[@pmurray8065]

FInally! Someone who can articulate clearly! This was enlightening; I am not a refrigeration tech. I am however looking for answers. I want to convert a refrigerator or a chest freezer to serve also as a freeze-dryer, which means I will need to be able to pull a vacuum, which means more modifications. Does a common freezer reach minus 40 F? How low does a common refrigerator go? Is it feasible to convert a refrigerator to a freezer and reach -40F? Thanks in advance for any answers and common sense advice. Your video was great.

[@robherch2312]

***** A common refrigerator uses the wrong refrigerant/pressure combination to reach very much below 32F/0C & a common "combo" fridge/freezer will likely only be able to reach slightly below 0F/-18C in the freezer section. A chest freezer, however, can often reach -20F/-28C, so could forseeably be capable of reacing -40 in a cold room, &/or with fairly minor modification (such as reducing the refrigerant charge, using an appropriate manifold, to lower the low-side boiling point).

[@pmurray8065]

That makes sense. Thanks for the insightful answers.

[@thietbibachma]

i have same troulbe with you. Now, have you found the solution for it? please tell to me?thanks so much

[@AntonBabiy]

you can look up the boiling point of any gas in a chart on Wikipedia and that will be the theoretical lowest temp for your refrigerant sys(you will never get that cold cause of higher pressure is sys). common refrigerant for eg R134a is -26C. If you want to go colder look into filling with R290(-42). This stuff gets really complicated real fast is you want to do something out of the ordinary and unless you have a good understanding of what you're doing I'd stay away from these experiments

[@richardbarber4444]

Philip Murray & @@robherch2312 IMHO dropping the 2nd stage, low temp., unit into the freezer cabinet is so simple and allows use of unpressurized medium for heat transfer to point of use.

[@Veptis]

Midwave infrared thermal cameras usually operate at 77K, so they use a Sterling cooler with a cold finger that is right at the back of the sensor. But others use LN2 or even stacked peltier elements.

[@johnfranks]

ooohh... You could build a super sweet cloud chamber with that!

[@crazyhans]

I'm waiting for the day you find some antiquated 1950s doomsday machine and get it working, is there anything you can't fix?

[@AmericanLocomotive1]

Believe it or not, if you want a lot information on cascade systems, go check out some of the various overclocking forums. There were people building 2, 3 and 4 stage cascades, some were even using auto-cascades.

[@elmajiko420]

Auto cascade systems are cool as hell!

[@张鑫-k2k]

are you interested in autocascade?

[@Exotic_Chem_Lab]

张鑫 yes im interested

[@Jimmy-qt3nx]

@@张鑫-k2k im interested in autocascade!

[@mr.phuonglanhcongnghiep]

Hi, would you like offering to me about the compressor brandname for ultra low temperature refrigerator systems?

[@bushsean]

You should come spend a day with me all I do is repair ultra-low cascade freezers. I have 700 of them in house at work. Including 100 Liquid Nitrogen freezers. We use mostly use propane, ethane, 404A and 508B. Couple of our units also had 134A.

[@josephbebout8259]

Me too, I've worked on ultra low for years but not this Sanyo box with a Intercooler heat exchanger, it looks waxed but this system has no waxy oil? have you worked on a Sanyo MFD 594?

[@phil955i]

@@josephbebout8259 hey Joseph I used to work for Sanyo Gallenkamp about 20 years ago. They had a 2 stage cascade pharmaceutical chest freezer that achieved -120 deg. C.

[@rc2466rc]

Are you in new york/ new Jersey Jersey?

[@DJignyte]

Excellent and informative video as usual. I'm interested to see what applications you have in store for this.

[@MSteamCSM]

This is just awesome. I wish to see some experiments with cold temperatures.

[@hla27b]

Excellent acquisition. Glad you made it work again.

[@Vikingwerk]

Could you do a video explaining how natural gas powered refrigeration works? I've read a fair amount about it, but it still does not quite make sense to me. I need one of your good explanations.

[@arunkumarsekar994]

Nice explanation of two stage refrigeration ( cascade process)

[@ShindenZero]

We'd love to see some experiments done with this thing!

[@Prophes0r]

I was curious about how much has changed since this video was posted in 2014. It only took me about 5 minutes to find a distributer claiming to have access to r1150 in the New Your area. And they were willing to sell me a small tank.

[@Exotic_Chem_Lab]

Overwatch i have made three stage cascade and i needed R1150 which was expensive so i made it myself at home from ethanol and aluminum oxide... I have it stored in my LPG tank 30 bars in 4 liter tank. I used it in my system and it worked perfectly... no problems till now

[@jorgeaugustobaudemont1861]

Thank you! Ben, very good information. I used to play with this systems but I never tried this set up. 😃

[@sinephase]

the system actually seems rather simple, pretty awesome you can make your own dry ice :P

[@girrrrrrr2]

Does this mean that we might see more freeze drying experiments?

[@compulsor5853]

Phase change point. Quote of THIS vid, great job as always

[@MajorHavoc214]

Wow, that sure will come in handy on a lot of projects.

[@phil955i]

What is the addition of the R1130 for in the 2nd stage? Wasn't even aware that you could still get R13B1, it was outlawed here in the UK in the early 90s as it was one of the most ozone damaging refrigerants. Same with R503. The cascade systems I used to work on used R502 on the first stage & R13 on the 2nd. Later on after the Montreal Protocol it was R404A on the 1st & R23 on the 2nd.

[@Exotic_Chem_Lab]

phil955i its R1150 (Ethylene).... Zero Ozone depletion... No contribution to global warming... But highly flammable

[@sparc5]

How can one dude be so smart? Do you have a hidden team of geniuses behind you like Khan Academy does? Did you get a certification for working on refrigerants? Can you please make a supercritical co2 air conditioner? :)

[@pedrobotinasguedes]

I'm always amazed with your deep knowledge.

[@theoabramovich3128]

You said your manual spec'ed a CFC refrigerant for the second stage, however the cover of the unit shows a "CFC free" decal. Perhaps there was a revised manual or a technical service bulletin to update to the Ethylene refrigerant.

[@Brant92M]

It seems a bit odd that the hot side condenser is so small. You're moving a hell of a lot of heat out of that chamber, how long does it take to get down to temp? I wonder what kind of regulation it can manage?

[@edwardhvacr4815]

I do have a manual somewhere like I said Thermo Fisher took over Revco Ashville N.C .When they did that they change assemble line from Ohio to N.C. They had so many problems they stop making them for a while in till the engineer had to find out how they where put together on the assemble line. Doing cascade refrigeration is challenging . Parts are OEM and refrigerant most of the time you could get the refrigerant from HVACR supply house would have to be license in the state to get the refrigerant .I never had a problem with refrigerant cost is high pre pound.

[@fegolem]

Can CO2 be carefully frozen such that it can form large single crystals? What shape would it be?

[@satibel]

you could probably put a bottle filled with co2 in there and wait

[@TheHunChem]

fegolem That would be nice. I imagine you can do it if you use a thermos or a well-insulated container for the slow heat transfer, but the CO2 subliming all the time right back to the gaseous phase would probably ruin the crystaline structure, so you would have a pretty much shapeless mass of solid CO2 at the end... But hey, we will never know without actually trying it out :)

[@phil955i]

I hope the first stage doesn't leak on that because R13B1 hasn't been available since the early 90s lol. Pretty sure there will be alternatives by now though ;-) When I was working for Sanyo 15 years ago they were making a -120 deg. C chest freezer by using just 2 stages when everyone else was using 3 stages to obtain the same temp.

[@ilyalevantis4184]

+Applied Science : What is the power draw of this machine both as it is getting down to temperature and once it is down to -100C with an insulated lid on the chamber? Would be interested to know if it would be viable to run this continually as an ultra-cold storage system.

[@Exotic_Chem_Lab]

Ilya Levantis its around 400W

[@Chr0nalis]

It's 30*Celcius here and seeing that foggy -100 chamber makes me want to jump in.

[@ThingEngineer]

Very interesting apparatus, thank you for the teardown and explanation!

[@SquirrelFromGradLife]

I see I've icecream being made in the future maybe combined with that accurate autoscale you built to make an ice cream on demand robot via the internet

[@joesmoe71]

Well that probably kills my idea of using a water cooler as a cold trap, I hadn't thought of the idea there may be a limit to what the coolant could handle. I was hoping I could maybe get it down to around -70f if I improved the cooling of the refrigerant on the condenser side as most coolers don't even have a fan, I wanted to try to build a freeze dryer without having to use dry ice.

[@Forge5894]

Quite interesting video, not something I see very often, thank you for posting it!

[@davegeorge7094]

Ethylene is used in place of acetylene. It should be easy to syn some up also. I always wished to build a 2 stage system. Propane should not be overlooked folks, cheap but you need to still it till pure.

[@886888aa]

Love the Harbor Freight Vacuum pump.

[@keepthinking2666]

I love using piercing valves AKA vampire tap when I was young didn't know any better but I wasn't doing ultra low this would be typically in a soda machine or something like a region nothing critical but yes the rubber that you put around the seal does leak

[@mattibboss]

Hi i have few questions How much it costs? How much does it take to freeze? If i pump co2 in there can i get dry ice out? I need dry ice or some cold stuff but storing dry ice sucks becouse it it vaporizes after 2 days in freezer (and Spending few euros every day plus cycling over 5km to get it really sucks) I was thinking about co2 bottle but it's expensive Maybe i could buy something like this put there full of dry ice and buy more every week or so How is this fridge thingy called? (so i can google) (sorry my English writing skill is not high enaugh for new words) Maybe you know good dry ice storage option? It can be liquid co2 too

[@dizzious]

Awesome! Super-cooling things is the bees knees.

[@cnc-ua]

Great Thank you for sharing. Would be cool to see any discovery about CO2 as a refrigerant.

[@DerekWoolverton]

You didn't mention where you eventually got the ethylene gas at, though since its used a lot for ripening fruit I wonder if you ended up at a farm supply house or nursery. These days of course you can get it on Amazon.

[@Arnthorg]

You could have a too low charge on the system. When adding refrigerant to a system you need to watch the suction pressure while it is running. Since Ethylenes boiling point is -103.7°C the pressure on the suction pipe when the system is running should be right above 0 psi gauge pressure to achieve -100°C. If there is not enough refrigerant in the system there will be vacuum in the suction side(meaning air could potentially be sucked in) and the compressor will not get enough cooling.

[@AureliusR]

How could air be sucked into a totally sealed system?

[@TednTin]

wow, Nice guess on the pressure

[@babylonfive]

Great stuff Ben.

[@mdesm2005]

Try setting up an oscillating magnetic field to see if you can create a Cells Alive System (CAS) freezer.

[@shocksplash6856]

ben, Im planning on doing one of these projects. I found one on ebay, the person states it powers on, but it does not get cold. so i would suspect its the refrigerant or some electronics. Where did you get the ethylene?

[@markbell9742]

Hi Ben: What are your thoughts on a kluged-up cascade refrigeration system starting with a couple of functional compressors and associated stuff. A priori, one would assume that the specifics of the compressor, capillary leak, etc. are optimized to a particular refrigerant. However, a quick Google indicates the capillaries are adjusted to produce a specific pressure drop. So, you would need to fashion a heat exchanger between the two units, charge one with a lower boiling refrigerant and fiddle with the pressures and the leak. Any thoughts. Cheers, Mark

[@satanshollowd]

Damn I had no idea such a thing existed. This would be an ideal device to begin phase change overclocking experiments with *goes on ebay*

[@davegeorge7094]

Can you give a hind of the kind of vendor? It's been three years now

[@Abdega]

So the lab that I work for has a two stage refridgerator that has nitrogen and helium sections, the problem is it apparently has been "broken" for over 10 years and I pretty much need it for experiments. I wonder if just using balloon grade helium at first would be a good test for it while trying to fix it since I don't really need to go all the way to 5 kelvin?

[@billyram999]

How much power is it drawing?

[@1989Chrisc]

billyram999 probably not much those compressors are usually around 150 watts and the condensor fan is probably around 25 - 50 watts..

[@moustaphamuhammad7013]

Hope you are doing well. I wanted to make exact replica of the refrigeration system. Can you give us the specifications of the 2 compressors and the 4 exchangers (2 evaporators and 2 condensers) also the size of the capillaries. Or how can we achieve those low temp. (~-150 degrees) by design a system using the r134a and r404a.thanks.

[@hailuassefa]

you make my life easy, thank you!

[@muhammadfaisalashrafi3018]

very help full video sir.. sir plz tell me the standing (idle) pressure of r-1150..i stuck in a job in india. & the charging process god bless you

[@BenTheMagnifice]

My new favorite AS video!

[@charlesfreitag5503]

Hi Ben! Love your vids, tyvm! I beg your advice..... i need to have a cold trap on my vac system but it's impossible to source bulk dry ice and LN2, no chance.... i cannot find an cryocooler that does not need external helium pump tho that would be ideal, would you say one of these is my next best choice, and would one of these be that much less effective than LN2? Tyia

[@dsetter608]

Hi Ben, I know this is an old video, but I hope you check in with the comments. I have the exact problem - loss of R-1150 refrigerant on the low temp side. I have a service training 2MB PDF from Thermo if you want it. My question is - Do I need a manifold specific for R-1150 or can any manifold work?

[@Exotic_Chem_Lab]

Any manifold can be used

[@robvermeulen7563]

Hi Don, I have one of these I want to work on, and the top cover won't come loose. It seems to hang up on the front even though all 3 screws on the bottom have been removed. What's the secret. The manual would also be handy.

[@dsetter608]

@@robvermeulen7563 Google my name and find my email. I am in Fitchburg WI.

[@Roger7137]

Hey Dude! Amazing your video. thank you so much! How about the size or wattage each compressor? How about low pressure side at the second stage working with ethylene? WR!

[@kylehammond]

That looks like a lot of fun!

[@NerdNordic]

Cool, thanks for the explanation! Now I wan't one of those!

[@markhumphrey4834]

very informative , brother,thanks for the excellent explanation .well done

[@arcadeuk]

Great video as always Ben

[@br6768]

Someone once told me the best refrigerants are flammable. I don't know if thats true, but it sounds cool.

[@richardbarber4444]

At the risk of being ridiculed by someone of greater knowledge... the common ones CFC's are not. Even the flammable ones are only flammable when they escape the closed system in which case they would probably be much diluted by ambient air. Propane, I have been told, can replace 134a in automotive applications. Much cheaper too.

[@BloodAltar1]

This video has taught me alot about refrigeration systems. This is a bit off topic from the video but how is that ruby laser going?

[@mduvigneaud]

Have you considered using the cold trap as the hot end for a Sterling heat pump to get even colder temperatures? I'm not sure what working fluid you would use, though. Helium is inherently leaky and hydrogen has an assortment of dangers (flammable and makes many metals brittle...)

[@johnguo4217]

Hello You are genius. Can you fix a ultra low freezer because it leaks. thank you

[@WTFChuk]

I find it odd that they chose R1150 to replace R503. R170 (ethane) is a better match to R503. perhaps they wanted a refrigerant that could make -1౦0C without having a suction pressure below atmospheric? Ethane can also be blended with propane in the proper proportions to replace R13B1. The resulting blended would have a glide but that would not affect system performance. I'd be willing to bet that instrument grade ethane and propane are both cheaper than ethylene.

[@brandonkolbe881]

Hey man! very nice repair. I have a couple of cascade chillers and they both stop cooling to -75C. The main (use) temperature slowly got warmer and warmer until I can not longer work with either. The sticker says R404 / R23A I am assuming this is for the two different compressors. What can of load should I use on each (either by mass or pressure)? can I change the refrigerants? Any technical suggestions would help. I need to get them back on line. Best; David

[@Dyllanes_Ingeniero]

Nice video. Good Job. Excelent. Thanks for share your experience and knowledge. Saludos desde México Amigo. Gracias