CO2 101 (with Don Gillis)
Don Gillis is a senior training specialist at Emerson, and he gives his CO2 101 class in which he explains the basics of CO2 in refrigeration. He also talks about the evolution of refrigerant regulations and does a demonstration of CO2's chemical properties with Trevor Matthews.
Don starts the class with a Kahoot game to introduce the basics of carbon dioxide's chemical properties. CO2 has a global warming potential (GWP) of 1, and it serves as the standard to which all other refrigerants are compared. Under atmospheric pressure conditions, solid CO2 sublimates and expands 845 times as it becomes a vapor. CO2 is approximately 1.52 times heavier than air. The critical temperature of CO2 is quite low, only 87.8 degrees Fahrenheit, meaning that the temperature-pressure relationship works up until that point. On the other hand, the triple point of CO2 occurs at 61 PSI; it may exist as a solid, liquid, or vapor at that pressure.
We used natural refrigerants, including CO2, before the invention of Freon. After that, natural refrigerants became less popular. However, the Montreal Protocol (and Kigali Amendment) have changed the regulatory landscape since then. As refrigerant regulations have targeted refrigerants with high ozone depletion potential (ODP) and GWP, natural refrigerants like CO2 have become commonplace in commercial refrigeration again.
At the moment, the United States' CO2 adoption is behind quite a few European countries and Japan, which have already incentivized the shift to natural refrigerants. However, the EPA is updating its older policies to move in the same direction as Europe and Japan (SNAP 2021 falls into that category). The California Air Resources Board (CARB) and the U.S. Climate Alliance are also committed to moving in that direction by phasing down high-GWP HFCs, starting with air conditioning and then moving to commercial refrigeration.
As popular high-GWP HFCs are slated for a phasedown, manufacturers like Emerson have been expanding their testing facilities to test flammable refrigerant (A2L and A3) alternatives to those HFCs. A2Ls (like the new low-GWP blends) are non-toxic and mildly flammable, A3s (like propane) are non-toxic and highly flammable, B2Ls (like ammonia) are toxic and mildly flammable, and A1s are non-toxic and non-flammable. Apart from the current high-GWP HFCs, the only A1 refrigerant that is suitable for refrigeration is CO2.
Natural refrigerants like CO2 are gaining traction in the US. When we think about refrigeration system architecture, we need to consider square footage, application (restaurants, supermarkets, etc.), and the type of refrigeration (medium-temp, low-temp, etc.). You may end up using a full-CO2 transcritical booster system, a partial-CO2 cascade, or a secondary system, which treats CO2 as a secondary fluid like glycol.
CO2 isn't toxic or flammable, but it displaces oxygen and may asphyxiate people if it fills a room due to its higher specific gravity; symptoms of excessive CO2 exposure range from drowsiness to shortness of breath to confusion to unconsciousness. Another danger comes from its high pressures. However, it can be exceptionally inexpensive and efficient, especially in low-ambient conditions. CO2 requires some special components (like pressure-relief valves), but it's future-proof and can be vented, so it has its benefits over HFCs.
When CO2 exceeds the critical point, it becomes a transcritical fluid that no longer obeys the temperature-pressure relationship; the condenser becomes a gas cooler instead. On the other hand, when CO2 drops below the triple point, it could become solid dry ice in the system. Transcritical systems under high pressure result in warmer CO2, and some facilities use that additional heat for heat reclaim. Cascade systems use subcritical CO2, which always stays below the critical point and is used exclusively in the low stage.
High pressure is a quintessential element (and hazard) of CO2 systems. Pressure relief valves are distributed throughout the system, and those are modulated by electronic controls. Standstill pressures depend on ambient conditions but are still high. Pressure is also in play during sublimation. Ice plugs may even form while charging, and they could be hazardous due to the high pressure that accumulates during sublimation. Even in the liquid phase, we need to control pressures to avoid expansion (hydrostatic conditions).
Don also covers:
Other natural refrigerant systems
Cylinder safety
Regulators and adapters
Refrigerant grade/quality
CO2 vs. glycol efficiency
CO2 rules and regulations
Industrial refrigeration trends
Ammonia system architecture
Liquid line insulation
Hybrid cascade systems in warmer climates
CO2 system challenges
VFDs, flash tanks, and system sensors
Adiabatic cooling
Read all the tech tips, take the quizzes, and find our handy calculators at www.hvacrschool.com/
Пікірлер: 61
great class . thanks for this video lecture
i fell asleep watching a baldurs gate video and woke up to this
@aaronroberts6782
2 ай бұрын
i fell asleep watching a build a shed video and woke up to this. Maybe the KZread algorithm and our AI overlords think we have the brain capacity to watch this because we watch Breaking Bad and geek out elsewhere like electrical engineering or something. Kind of flattered actually.
*** Save time. No big picture / executive summary at the beginning. Start at 1:22:00 (one hour 22). You get to miss the ozone gwp lecture and start with the benefits of CO2. The main course still is an additional hour away. The slides are nearly useless because they re difficult to read. The key portion of transcritical, all co2 system technology is rushed to a fault at the end.
Best technical class I've ever attended!
This video has been put in my You Tube‘s file to be saved as best overall CO2
Awesome Presentation
The audio is distorted because the pre-amp in the audio system is being overdriven. The volume is too high on some device in the audio production chain.
thanks for sharing, im retired, a ton of useful information for those who care to view and listen,,,, all good
Tremendous class
There are times where i go to a service call at an absolute dump of an apartment complex, the management doesnt care, the tenants dont care, and they dont want to pay for the job to be done correctly, i find it very had to do a good job in those situations.
Thank you
How can I get a copy of the presentation to review? (difficult to see in the video)
the biggest problem with selling dry ice is the storage of the product. the temperature of dry ice is close to -100 degrees, so a normal freezer isn't cold enough. this means you're loosing a lot of product if its not sold right away.
@matthewholmes9986
Жыл бұрын
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@matthewholmes9986
Жыл бұрын
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@somethingsinister6789
Жыл бұрын
O😊u😊it’d
hey, just wondering can we get the link to download this amazingly informative PDF presentation? thank you
Great class. I attended Don’s CO2 class in Sacramento California last year.
Thanks!
super great installation...thanks and God bless
Can someone tell me the name of that book?
How can I join this Live training?
Great
Anyone have a link to the slides from the presentation?
I'm about to go insane trying to figure out why that man's voice is so familiar to me.. without a doubt I've heard his voice radio or Tv. Commercial.. tell me I'm not the only one
Does anyone else purge and pressure test with co2 instead of nitrogen? A bottle of co2 lasts like 10 times longer because its liquid, co2 is cheaper, and co2 is still inert at those pressures.
Is there something about CO2 that makes it more of an asphyxiation hazard than any other class A (low toxicity) refrigerant? The CFC, HCFC, HFC, and HC refrigerants we are used to working with will all displace oxygen and are all denser than air, so how is CO2 worse?
@randymoreno9345
Ай бұрын
The leak rate (due to its higher pressure) and the expansion ratio of liquid to vapor, decreases the time it takes to displace the oxygen in the room.
I’m finding it crazy that we as an industry are being shoved around by the new world order of goofy people who are totally disconnected from the economic problems that they are inflicting on us as a result of their poor operation and over-regulation… let’s see how much we can force consumers into….
@blackCladLad
8 ай бұрын
you’re someone that bitched when they made seatbelts a law, huh
@thunderboltpenetrator8498
7 ай бұрын
We'll have fossil fuels forever?? You're as smart and as old as a coal miner... You better keep u working the changes you old dinosaur... Or you will go extinct.
@cheefussmith9380
7 ай бұрын
@@thunderboltpenetrator8498that’s not inconsistent with what he said you smug prat
@connorcruz6249
5 ай бұрын
@@thunderboltpenetrator8498you can't change them dude, If we lived in this guy's world we'd still be riding around on horses
@joeyaayeoj
3 ай бұрын
@@connorcruz6249 if policymakers actually cared about practicality or climate change we would be building high speed rail... and they'd decomission their private jets..
The first five minutes were scintillating
@Matowix
Жыл бұрын
Did we need to see his wife 😲
有没有中文字幕
Use R152a computer duster.
~ Thank God that Troll is No Longer in Office ~
Fast forward to 1 hour 50 mins
I worked on an r-290 system for the first time a couple years ago. Three ounces is difficult to weigh in. CO2 will prove to be the most dangerous to technicians it think. 1600 psi is no joke.
Video starts at 10 min. Music nearly made this unwatchable.
For me Don talks and moves too much and too fast. He’s talking faster than I can process. He’s good for the younger crowd.
Does any one have a phone.? No but I do have a party line. Are we not in the 21 Century
And don't get me wrong here, UV protection from ozone is also very important, and we should do everything possible to make sure this layer does not get damaged any further. I love the idea of CO2 as a refrigerant, I love the idea of CO2 capture to use it as a drilling and extraction aid for gas and oil. And please do not mention dino anything when speaking of petroleum products......the dinosaur story is just that.......a story. We should be preparing for the super flare/cme event that is going to cripple us as our magneric field continues to weaken at faster rates than anticipated. All these electrically powered systems are going to be obliterated unless we start to innovate and produce better protection systems for grids worldwide. S. Obsrvr.
It doesn't seem smart to move towards another as a refrigerant that is so widely demonized by half the country
@banalMinuta
9 ай бұрын
Dude CO2 isn't demonized, people are mad at the politicians and lobbyists who used Fox News to dupe people into thinking stuff like CO2 is irrationally "demonized". Or that letting companies release as much pollution as they want was a completely consequence free policy.
Global warming potential... nice
He spent to much time in the GWP and effects on ozone Needs to teach service and repair Not a good class at all
the circus goes on
The video is awful. Can’t see the screen , to far.
Ridiculous
California ruins everything
Bullshit