HFOs are third generation refrigerants, replacing HFCs, which in turn replaced CFCs.
In 1985, CFCs were recognized as destroying the ozone layer, so they were banned in 1989 and replaced them with HFCs that didn't do that.
The problem with HFCs was that they have 5,000-10,000x greenhouse warming potential relative to CO2. So in 2006 the EU mandated that cars replace HFCs with less potent substances. After 10 years of development and testing, HFOs were finally phased into usage, with most cars using HFOs in their air conditioning.
Heat pumps and HVAC units seem like they're a decade behind autos, but their HFCs should likely be replaced with HFOs, too.
The TFA comes from atmospheric degradation of these HFOs. Scaremongering about TFA without the counterbalancing story of why TFA is showing up and the decades of social, political, and technical work behind HFOs, pisses me off to no end.
Just use propane. This bullshit with inventing ever more elaborate synthetic compounds which turn out to be toxic has got to stop. We should be denigrating "the decades of social, political, and technical work behind HFOs".
Yeah, natural refrigerants are the way - CO2, hydrocarbon gases, ammonia (in industrial settings), water/steam, and air - these can pretty much cover the entire temperature range that you will ever need in heat pumps.
The natural refrigerants are indeed becoming increasingly popular. Essentially all new supermarket refrigeration systems in Europe are CO2-based nowadays, as an example. And almost all domestic fridges are using isobutane, freezers are using isopentane.
Unfortunately there is a large push behind synthetic refrigerants, because there is a large industry who makes money off selling these compounds and would like to keep it that way.
In general you need to build the whole heat pump (incl. compressor) for the specific refrigerant and application you have in mind.
So if you have an existing line of products using synthetic refrigerants, and a dozen factories around the world making those, you might very well choose to listen to a manufacturer of synthetic refrigerants pushing a new fancy one, rather than decide you need to re-engineer all your products for natural working fluids.
Or, in other words, for using CO2 efficiently on an environment-temperature heat pump, you need it to sustain higher pressures at both the hot and cool sides, and both the pump and nozzle to survive dealing with a higher density fluid that acts in many ways like a liquid.
That explains why people keep searching for a different gas. What is interesting is that it's probably the best gas for that kind of cycle on environment-temperature, as it's too cold for water and amonia, but a low condensing pressure is a benefit here.
Yeah, I don't really know that much about refrigeration, but that's my take as well. If I had a choice, I'd just run all my stuff with propane, but I don't really know how feasible that is - could I just jury-rig up some hoses and go around charging things? Or are there parts of the system that won't abide by that?
I believe the stated rationale against propane is flammability, but is that really that much of a concern? Presumably you aren't mixing oxygen and propane in the system, so basically you've just got propane lines circulating in your house/car. Big whoop, I've got methane lines in my house already, and the car has plenty of other flammable things too.
Only if they run similar pressures. R-22 is basically the same pressure as R-290 (propane) but all the newer stuff is much higher. I think that means it ends up icing over really quick.
A propane/isobutane blend is a good replacement for R-12 which was the refrigerant used for air-conditioning before CFCs were banned. Straight propane as you note is better for freezers than air conditioners.
A problem with blended refrigerants is that if there is a slow leak the blend will change as the refrigerant leaks out, due to the different partial pressures. That makes recharging more difficult, you basically have to vacuum out the system and recharge with the correct mixture.
Also, propane and isobutane are both flammable, but other than CO2, most refrigerants are to some degree.
Many things can ignite during accidents, such as the 10-20 gallons of gasoline in an average automobile tank. The tanks tend to be pretty well protected, and an air-conditioner condensor is normally at the very front end of the car, but that design could be changed.
There's around 3lb of it, around half a gallon equivalent of gasoline.
That's not nothing, but it's not that much that we should be extremely worried - there's around the same amount of fuel in the various lines running from the gas pump to the engine.
It also helps that as a vapor it will dissipate very quickly.
Yes, most hvac and refrigeration units are a generation behind, so perhaps the issue will only grow with time. More info: https://appliance.report/gwp/
This summarizes the dangers of trifluoroacetic acid (TFA). It’s a small polar compound that has low potential for toxicity. I mean not great that it is in drinking water but in the grand scheme of things it could be much worse.
>As an acid or as a salt TFA is low to moderately toxic to a range of organisms. Based on current projections of future use of HCFCs and HFCs, the amount of TFA formed in the troposphere from substances regulated under the MP is too small to be a risk to the health of humans and environment.
The article quotes low to moderate risk, an acceptable threshold is no to very low risk. Also the existence of TFA in drinking water is a much larger concern than TFA in the troposphere
> The study acknowledged that there is currently little to no data about long-term exposure of ultra-short chain PFAS like TFA.
That's a bit worrying.
Although I don't know how expensive and difficult it would to make sure this would be safe to drink, and what toxicologists need to do to properly test those chemicals.
Sometimes I wonder, how do researchers in toxicology try to explore chemicals that have not been tested yet. Most of the time, the company who makes those chemicals have the money to test them, but when they find a problem, they make sure to not tell anyone, and just "advise" to use chemical A or B this way, but not this way.
And that's how the roundup problem came to happen, because users were not told to use a moderate amount, because the companies failed to properly warn the public.
It guess those small chemicals can't be filtered by carafe/brita filters?
"TFA's reaction with bases and metals, especially light metals, is strongly exothermic."
and:
"TFA is virtually non-degradable (persistent) in the environment."
Can both be true. There are trace amounts of metals in sea water, and in soil. It might take some time, but the TFA will encounter the metal, and if it's that reactive, it should react with it, even at low concentration. It should make a metal fluoride.
Maybe lead is a bad example, because it was known to be bad for a long time... But what is the thing that looking back will turn out to be horrible for us and pervasive in the environment?
I’d say micro plastics and other related chemicals like PTFEs. They’re incredibly common and found throughout the human body and in every ecosystem. I have a feeling a lot of modern diseases, the ones relegated to “developed” countries are created or exacerbated by plastic chemical pollution. We know they can disrupt hormones and who knows what else. Worst of all they’re impossible to avoid
Plain old atmospheric CO2. We've upped the amount in our atmosphere to well over 400ppm. Drowsiness becomes noticeable at over 1000ppm but with the now higher atmospheric CO2 and the fact that many of us now live and work indoors where poor ventilation can increase CO2 levels you have a recipe for subtle cognitive problems similar to what lead caused.
He does sound a bit "out there" but mainstream science says that vegetable/seed oils are safe to eat, so anyone who says they are not is going to be "anti-science."
There are plenty of mainstream science studies on oils, not all of them favourably disposed, and "is ingredient x bad for you" has never been something that's been difficult to get mainstream funding for. If it was the case that the only indication of negative health consequences of cooking oils came from an "out there" self-publicist that would be a [weak] prior in favour of the safety if oils, not a reason to pay particular attention to the "anti-science" arguments of the "out there" guy on this topic.
He cites no sources for any claim of adverse health effect. Also, evolutionary mismatch is the kind of nonsense common in alternative circles that we can do well without.
I’ve read #1 and #5 so far, and they were both fascinating. Thanks for sharing this! I figure the actual answer is a combination of many things, but reading each of these little pieces is really valuable info.
I suspect nothing - Lead is unique in that the cognitive effects of exposure can cause societal collapse if widespread enough.
We have other environmental contaminants that are bad but broadly, they don't have the cognitive effects of Lead - biologically you can survive lead exposure - meaning you wont die - but the cognitive exposure of Lead in my opinion puts it in a category of its own.
Phthalates seem to have similar society-collapsing potential through population decline. Different mechanism but I'm not sure the outcome is different in a meaningful way.
Industry invents A, which is useful but has bad side effects causing A to get banned. Industry invents B, which does the same thing, maybe not quite as well, and with its own bad side effects, and might be chemically very close to A, but it's technically not A so it can be sold. B gets banned. Repeat.
You prove GP's point. If the EU regulatory experts are so smart they can tell everyone else what to do perhaps they should have mandated a safe chemical.
You can't take responsibility for something, enforce changes, and then say you're not responsible for the outcome. They do this all the time, see cookie banners.
Governance like this creates problems instead of solving them.
> If the EU regulatory experts are so smart they can tell everyone else what to do perhaps they should have mandated a safe chemical.
> You can't take responsibility for something, enforce changes, and then say you're not responsible for the outcome.
Demonstrating that a particular chemical has particular bad consequences is a lot easier than inventing a replacement. Are you saying regulatory agencies shouldn't exist unless they can replace the industries they regulate?
In 1985, CFCs were recognized as destroying the ozone layer, so they were banned in 1989 and replaced them with HFCs that didn't do that.
The problem with HFCs was that they have 5,000-10,000x greenhouse warming potential relative to CO2. So in 2006 the EU mandated that cars replace HFCs with less potent substances. After 10 years of development and testing, HFOs were finally phased into usage, with most cars using HFOs in their air conditioning.
Heat pumps and HVAC units seem like they're a decade behind autos, but their HFCs should likely be replaced with HFOs, too.
The TFA comes from atmospheric degradation of these HFOs. Scaremongering about TFA without the counterbalancing story of why TFA is showing up and the decades of social, political, and technical work behind HFOs, pisses me off to no end.