I remember thumbing through one of those really old refrigeration technology magazines from the 1910's or so, and among the many ads for ammonia for sale, there was an ad for CO2. So it was being used for industrial refrigeration. Ammonia was apparently king, but there must've been enough CO2 equipment in service to warrant a company advertising that they were selling CO2. Funny how old things become new again.
Yeah, I was just thinking how bizarre it’d be, if Global Warming was to eventually (in time) become fully offset by the implementation use of Co2 for all newer “cooling” systems… eventually even efficient enough to warrant the manufacturing of units like above, to be designed to swap out older systems of existing systems… heck, how strange would it be, if gasoline powered vehicles were equipped with tech to accumulate, compress, condense and, inject the Co2 from exhaust, right into a reservoir for the cooling system?!! Instead of continuing to spew it right out into our environment… fascinating subject
Anytime I find a seized motor like that fan, I am not satisfied until I've gotten it apart and gone into both bushing and shaft surfaces with a solvent-soaked Q-tip and cloth and removed all traces of the gummed up oil that caused the seizure. Then I liberally re-oil the bearing wicks. Reason being leaving the gummed up lube in place, even with lots of fresh oil invites a repeat seizure not long after. Better safe than sorry.
Completely agree with you on this! Were I to put this system back in service, I would just replace the fan motor. These are inexpensive and easy to get. Were it a more vintage or unavailable fan motor I would definitely take the whole motor apart and clean as you explained.
I read that the first refrigeration units to use R744 were built around the turn of the last century but they were impractical because the technology wasn't there to make sufficiently strong lightweight tubing. If it's only 900 psi then this is operating in the subcritical regime. This can greatly reduce the operating efficiency at high ambient temperatures because of the very low critical temperature of 87.8 degrees Fahrenheit.
You're right. I don't expect it to work well at all in high ambient temperatures. Larger rack type transcritical systems have many parts not normally present on small systems, such as throttling valves in the high side, and flash gas separator, and multi-stage compressor to deal with intermediate pressure flash gas recycle. All of these parts require regulation of some sort, which is economical on large systems with PLC controls and lots of space for the instrumentation necessary to operate them. The small system in this video is very inefficient because all of the flash gas goes through the evaporator and provides no cooling but does provide load on the compressor. The low critical temperature of CO2 it's a huge thorn in the engineer's side because it either causes a very inefficient system, or requires a very complex system. These seem to be more or less a sales gimmick, aka "greenwashing" to sell more soft drinks.
That's really interesting. When you shut the compressor off I didn't hear any residual liquid boiling off / circulating like one does on a "traditional" system.
I’ve got a number of fans that had previously locked up, I’ve found that they sometimes lock back up if left to sit. However if I soak the bearings in solvent and heat them with a torch to ensure any garbage is driven off, they work like new. But it’s not always worth it.
Good point. If the pores in the bushing are clogged with dried oil, the new oil typically won't penetrate and maintain a film. Heating the bearing will help melt out and clear the pores. I tend to have problems trusting motors which have had bearing seizures especially in applications where a fan failure can cause damage to other components.
@@davida1hiwaaynetthe only way I will trust a motor is to do a trial run for a period of time to ensure that no issues come up, even then I am still cautious. Especially on something worthwhile.
Most of the time the porous sleeve gets blocked with its own displaced material from the prior lack of lubrication. They typically lock back down, sadly. I have had some success with using fine grit sandpaper to lightly scuff the bearing surface so that the oil will wick through to the shaft.
Fascinating! I had never heard for CO2 being used as a refrigerant other than in the form of dry ice of course. You had mentioned that CO2 was one of the first refrigerant but was replace with others due to the high pressures required. The compressor with its clean labeling looked fairly new. I wonder why they would have used CO2 - I guessing there must be some advantage for certain applications?
He says it is from a vending machine. I know Coca-Cola had a big push to transition their machines away from R134a to CO2. Most likely an environmental decision on their part.
Thanks for the comment! This was indeed from a soft drink vending machine and it is approximately one year old. There are no technical benefits to this type of system compared to other lower pressure refrigerants. It is solely for one purpose, which is to make the general public perceive that the owner is watching out for the environment. These exist because "greenwashing" sells products in this day and age. It's a false concept in this case because this unit is extremely energy-inefficient and they have proven to have short lives. The manufacturer replaces them with R134A systems. Don't get me wrong, we need to look out for the environment but this is not the way to go about it.
@@davida1hiwaaynet I never would have guessed it was "greenwashing" . Sad how well meaning people result in companies doing this. I always think if money was spent in a way to get most environmental "bang for the buck" we would be so much better off...
It is interesting sounding. I would like to see how it is constructed to operate at such a high pressure. I would expect a long-stroke design with large amount of piston-bore interface for sealing.
Also known as "carbonic acid" or "carbonic anhydride" back then, as in 19th century. There's an article called "The Rise and Fall of Carbon Dioxide Systems" you can easily find online with some more interesting details about the early days of CO2 refrigeration. Compressors for CO2 are designed more like those for high-pressure air (1k PSI+), with long and narrow pistons.
With those pressures I had to go look up a manifold set for R744 and see what the hoses looked like and they have some serious looking braided hoses for those pressures..
Thanks. Just to be sure you realize.... this is engineered from the get-go to be an R744 system. It was never an R134A system. It's already several years old and still works. If it were engineered for R134A and charged with R744; the compressor casing would have probably exploded and resulted in a fatality.
@@davida1hiwaaynetbrazed copper coil condensor ends and brazed copper is not suitable for 30 bar CO2 discharge pressures.......... It will fail in service 🤦
@@fenflyer Actually; they make copper tubing of different specifications and wall thicknesses. As hard as it may be for you to believe, this is a factory built unit and is engineered for R744. While they are not considered reliable by most standards, tubing failures are not a problem.
So I'm curious how there would still be any c02 systems in operation? That one looks fairly modern. In my younger years, I used to build often from scratch many home made refrigeration projects. I'd salvage dehumidifiers often. At one time decades ago when I was a kid an old appliance repair man gave me junk yard condemned parts like compressors and whatever else I could salvage. After HS I took refrigeration, but ended up going back into broadcasting. Unfortunately kinda lost interests in playing with it when I moved back home. Made alot of interesting things including a walk in cooler system.
Thanks for the comment! This was indeed from a soft drink vending machine and it is approximately one year old. It seems that the lessons learned about the early CO2 systems in the 20's and 30's have been lost. There are no technical benefits to this type of system compared to other lower pressure refrigerants. These units are extremely energy-inefficient and they have proven to have short lives. The manufacturer replaces them with R134A systems. I also love learning by taking apart and fixing junked things. Often you find that not much is wrong!
I'd like to see the working pressures for that thing. Maybe it's just me, but this looks too simple for transcritical cycle. If it is indeed not, then I wonder how it would work with the environment temperatures above 30°C (75°F).
You're right. I don't expect it to work well at all in high ambient temperatures. Larger rack type transcritical systems have many parts not normally present on small systems, such as throttling valves in the high side, and flash gas separator, and multi-stage compressor to deal with intermediate pressure flash gas recycle. All of these parts require regulation of some sort, which is economical on large systems with PLC controls and lots of space for the instrumentation necessary to operate them. The small system in this video is very inefficient because all of the flash gas goes through the evaporator and provides no cooling but does provide load on the compressor. The low critical temperature of CO2 it's a huge thorn in the engineer's side because it either causes a very inefficient system, or requires a very complex system. These seem to be more or less a sales gimmick, aka "greenwashing" to sell more soft drinks.
This is fascinating! Are there any advantages to CO2? I know it requires higher pressure, and by definition has a green house gas factor of only 1, but is it more efficient? Can it get colder maybe?
I remember thumbing through one of those really old refrigeration technology magazines from the 1910's or so, and among the many ads for ammonia for sale, there was an ad for CO2. So it was being used for industrial refrigeration. Ammonia was apparently king, but there must've been enough CO2 equipment in service to warrant a company advertising that they were selling CO2. Funny how old things become new again.
Yeah, I was just thinking how bizarre it’d be, if Global Warming was to eventually (in time) become fully offset by the implementation use of Co2 for all newer “cooling” systems… eventually even efficient enough to warrant the manufacturing of units like above, to be designed to swap out older systems of existing systems… heck, how strange would it be, if gasoline powered vehicles were equipped with tech to accumulate, compress, condense and, inject the Co2 from exhaust, right into a reservoir for the cooling system?!! Instead of continuing to spew it right out into our environment… fascinating subject
It is funny, how old things become new again. And lessons lost and history repeats.
Anytime I find a seized motor like that fan, I am not satisfied until I've gotten it apart and gone into both bushing and shaft surfaces with a solvent-soaked Q-tip and cloth and removed all traces of the gummed up oil that caused the seizure. Then I liberally re-oil the bearing wicks. Reason being leaving the gummed up lube in place, even with lots of fresh oil invites a repeat seizure not long after. Better safe than sorry.
Completely agree with you on this! Were I to put this system back in service, I would just replace the fan motor. These are inexpensive and easy to get. Were it a more vintage or unavailable fan motor I would definitely take the whole motor apart and clean as you explained.
Very cool unit and find. Thank you for sharing.
Glad you liked seeing it! Appreciate the comments.
I read that the first refrigeration units to use R744 were built around the turn of the last century but they were impractical because the technology wasn't there to make sufficiently strong lightweight tubing.
If it's only 900 psi then this is operating in the subcritical regime. This can greatly reduce the operating efficiency at high ambient temperatures because of the very low critical temperature of 87.8 degrees Fahrenheit.
You're right. I don't expect it to work well at all in high ambient temperatures. Larger rack type transcritical systems have many parts not normally present on small systems, such as throttling valves in the high side, and flash gas separator, and multi-stage compressor to deal with intermediate pressure flash gas recycle. All of these parts require regulation of some sort, which is economical on large systems with PLC controls and lots of space for the instrumentation necessary to operate them.
The small system in this video is very inefficient because all of the flash gas goes through the evaporator and provides no cooling but does provide load on the compressor. The low critical temperature of CO2 it's a huge thorn in the engineer's side because it either causes a very inefficient system, or requires a very complex system. These seem to be more or less a sales gimmick, aka "greenwashing" to sell more soft drinks.
I really enjoyed the re-oiling of the fan and hearing it slowly whirl back to life :)
Extremely awesome unit. I have read a lot about Co2 refrigeration but this is the first video I have seen with a working unit
Thanks. It's fortunate that I got it as these are still fairly new. There is very little info available about it.
Nice find I love that start-up sound from the refrigeration unit
That's really interesting. When you shut the compressor off I didn't hear any residual liquid boiling off / circulating like one does on a "traditional" system.
Wow ! That's really cool. I can't believe it can withstand 900 PSI. impressive little unit 👌
Thanks! It is a neat little unit.
I’ve got a number of fans that had previously locked up, I’ve found that they sometimes lock back up if left to sit. However if I soak the bearings in solvent and heat them with a torch to ensure any garbage is driven off, they work like new. But it’s not always worth it.
Good point. If the pores in the bushing are clogged with dried oil, the new oil typically won't penetrate and maintain a film. Heating the bearing will help melt out and clear the pores. I tend to have problems trusting motors which have had bearing seizures especially in applications where a fan failure can cause damage to other components.
@@davida1hiwaaynetthe only way I will trust a motor is to do a trial run for a period of time to ensure that no issues come up, even then I am still cautious. Especially on something worthwhile.
Most of the time the porous sleeve gets blocked with its own displaced material from the prior lack of lubrication. They typically lock back down, sadly. I have had some success with using fine grit sandpaper to lightly scuff the bearing surface so that the oil will wick through to the shaft.
Fascinating! I had never heard for CO2 being used as a refrigerant other than in the form of dry ice of course. You had mentioned that CO2 was one of the first refrigerant but was replace with others due to the high pressures required. The compressor with its clean labeling looked fairly new. I wonder why they would have used CO2 - I guessing there must be some advantage for certain applications?
He says it is from a vending machine. I know Coca-Cola had a big push to transition their machines away from R134a to CO2. Most likely an environmental decision on their part.
Thanks for the comment! This was indeed from a soft drink vending machine and it is approximately one year old. There are no technical benefits to this type of system compared to other lower pressure refrigerants. It is solely for one purpose, which is to make the general public perceive that the owner is watching out for the environment. These exist because "greenwashing" sells products in this day and age. It's a false concept in this case because this unit is extremely energy-inefficient and they have proven to have short lives. The manufacturer replaces them with R134A systems. Don't get me wrong, we need to look out for the environment but this is not the way to go about it.
Exactly.
@@davida1hiwaaynet I never would have guessed it was "greenwashing" . Sad how well meaning people result in companies doing this. I always think if money was spent in a way to get most environmental "bang for the buck" we would be so much better off...
@@ElectromagneticVideos You got that right! Sad it is how the general public is so easily swayed, without really seeing both sides to any story.
Very interesting sound of the compressor.
Greets from Germany
It is interesting sounding. I would like to see how it is constructed to operate at such a high pressure. I would expect a long-stroke design with large amount of piston-bore interface for sealing.
Thanks for sharing David.
Also known as "carbonic acid" or "carbonic anhydride" back then, as in 19th century. There's an article called "The Rise and Fall of Carbon Dioxide Systems" you can easily find online with some more interesting details about the early days of CO2 refrigeration. Compressors for CO2 are designed more like those for high-pressure air (1k PSI+), with long and narrow pistons.
With those pressures I had to go look up a manifold set for R744 and see what the hoses looked like and they have some serious looking braided hoses for those pressures..
really awesome find it would be nice to see it in a project like a cooler I love these refrigeration videos you put out keep up the good work 😀
Nice
Thanks!
Nice vid .......
Unfortunately this won't last few days running CO2 @ 4x pressure of R134a 🙈
Thanks. Just to be sure you realize.... this is engineered from the get-go to be an R744 system. It was never an R134A system. It's already several years old and still works.
If it were engineered for R134A and charged with R744; the compressor casing would have probably exploded and resulted in a fatality.
@@davida1hiwaaynetbrazed copper coil condensor ends and brazed copper is not suitable for 30 bar CO2 discharge pressures.......... It will fail in service 🤦
@@fenflyer Actually; they make copper tubing of different specifications and wall thicknesses. As hard as it may be for you to believe, this is a factory built unit and is engineered for R744. While they are not considered reliable by most standards, tubing failures are not a problem.
Nice trick with the electric oil. I ownder if this also works with bigger fans, ie like 3phase fans. Might safe a day in a pinch
So I'm curious how there would still be any c02 systems in operation? That one looks fairly modern. In my younger years, I used to build often from scratch many home made refrigeration projects. I'd salvage dehumidifiers often. At one time decades ago when I was a kid an old appliance repair man gave me junk yard condemned parts like compressors and whatever else I could salvage. After HS I took refrigeration, but ended up going back into broadcasting. Unfortunately kinda lost interests in playing with it when I moved back home. Made alot of interesting things including a walk in cooler system.
Thanks for the comment! This was indeed from a soft drink vending machine and it is approximately one year old. It seems that the lessons learned about the early CO2 systems in the 20's and 30's have been lost. There are no technical benefits to this type of system compared to other lower pressure refrigerants. These units are extremely energy-inefficient and they have proven to have short lives. The manufacturer replaces them with R134A systems.
I also love learning by taking apart and fixing junked things. Often you find that not much is wrong!
Make a good air con
Wonder if thats some kind of long stroke reciprocating compressor thats a Thai unit
You can see why CO2 was not used for air conditioning because the pressures were way too high. Would’ve resulted in extremely inefficient ac systems
Many of these are already replaced with R134A systems due to the reliability and energy use issues with them.
I'd like to see the working pressures for that thing. Maybe it's just me, but this looks too simple for transcritical cycle. If it is indeed not, then I wonder how it would work with the environment temperatures above 30°C (75°F).
You're right. I don't expect it to work well at all in high ambient temperatures. Larger rack type transcritical systems have many parts not normally present on small systems, such as throttling valves in the high side, and flash gas separator, and multi-stage compressor to deal with intermediate pressure flash gas recycle. All of these parts require regulation of some sort, which is economical on large systems with PLC controls and lots of space for the instrumentation necessary to operate them.
The small system in this video is very inefficient because all of the flash gas goes through the evaporator and provides no cooling but does provide load on the compressor. The low critical temperature of CO2 it's a huge thorn in the engineer's side because it either causes a very inefficient system, or requires a very complex system. These seem to be more or less a sales gimmick, aka "greenwashing" to sell more soft drinks.
Очень интересная штука на углекислом газе.
This is fascinating! Are there any advantages to CO2? I know it requires higher pressure, and by definition has a green house gas factor of only 1, but is it more efficient? Can it get colder maybe?
Not sure i see the advantage over an r290 unit.
Especially if it has to run trancritical, maybe inside an already conditioned space.