PFAS ban affects most refrigerant blends | Hacker News Reader

PFAS ban affects most refrigerant blends

coolingpost.com

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Do the remaining alternatives work, and are they excessively expensive?

> Laboratory test equipment and centrifuges would receive a 12-year exemption as no alternatives are currently available.

Oh, so there are no remaining alternatives that work in these applications.

There are a lot of alternatives that are cheap and perform well... but many of those have other safety concerns.

Some common examples are hydrocarbons or ammonia: https://en.wikipedia.org/wiki/Natural_refrigerant

Ethane (R-170) is a fine low-temperature refrigerant for lab equipment. The performance characteristics are at least as good as halocarbon refrigerants. The main drawback is flammability but propane has a similar concern and is already widely used in residential refrigerators and similar size systems.

From personal experience things using propane refrigerant seem to make a high pitched noise, I'm not sure if that's a property of the refrigerant or how devices using it are built.

There's no "reason" propane has to be louder but most propane refrigeration systems are used in industrial or cost-conscious applications where making the equipment quiet is less of a priority. When designing pumps it takes a non-trivial amount of engineering effort to ensure that the bulk of the noises emitted are above/below human hearing range.

>widely used in residential refrigerators and similar size systems.

Not in the US (because of the flammability), unless something's changed very recently.

In the last few years, the US has finally started allowing small appliances containing limited quantities of flammable refrigerants.

USA is kind of the exception. In much of the rest of the world, propane or butane are the norm in domestic refrigerators.

Most of the world doesn't build their residential buildings out of light wood frame :/

A fuel-air explosion will not be contained by a reasonable amount of concrete or masonry. The real safety lesson is to control sources of ignition and prevent the buildup of released gases.

If your house is on fire, you best GTFO no matter what kind of refrigerator you have.

American homes have plenty of propane/natgas appliances anyway, so what difference does one more make?

People usually store their propane tanks outdoors.

And they have natural gas piped into the house.

the volume in a pipe is a lot less than what you'd find in a tank, especially considering the pressure in said pipes is usually one tenth of a psi (.6 kPa)

In the US it's typically more like 0.25psi, I don't know about elsewhere.

But it's connected to what you might consider a tank of nearly infinite volume. It's flow rate limited, but it's fast enough to get an entire house to explosion concentration in much less than a day. Perhaps only an hour.

Point is that we humans manage to figure out how to harness things that might be dangerous when they're useful. And hydrocarbon refrigerants can be very useful so we might figure out how to deal with the relatively small danger they pose.

I don't disagree to be clear, I'm just saying treating it differently than a gas pipe isn't totally crazy. A punctured refrigerant line will empty in a few minutes, and it's next to a compressor that'll likely generate a spark when it kicks on. Even if it just means we need to use thicker line, lets do it.

Notably, Propane has almost identical refrigeration characteristics to R-22, so it was an easy drop-in replacement for systems designed for R-22 when that was banned.

I don't see why, they're hardly less flammable

In commercial applications you'll see R-290. It's often used in low temperature applications, like ice cream display freezers. I've seen them in gas stations and pizza shops quite a bit.

> Not in the US (because of the flammability), unless something's changed very recently.

I don't know when it changed but R-290 (propane) is allowed up to 13oz. My ice maker uses it. I believe it must also be sealed without service ports both to prevent leaks and prevent anyone from connecting normal A/C service equipment to the system. Service requires emptying the system then brazing service ports onto the fill pipes (which are left much longer than normal for this purpose).

I've seen pentane used in small refrigerators in the US.

Magnetic refrigeration seems (to a complete layman) to show promise.

https://en.wikipedia.org/wiki/Magnetic_refrigeration

I for one, hope that someone figures out a way to make this cost effective.

I think thermoacoustic coolers are another promising solution.

I remember reading about this in Popular Science in high school. Residential refrigerators powered by this technology by 2006! Twenty years after that magazine article I haven't seen any substantial progress towards a commercial product.

The problem with most alternative refrigerant technologies (magnetocaloric, electrocaloric, thermoelectric) is the same: the temperature deltas tend to be rather small, at best 25 C. That is roughly the thermal performance of the recently published "ionocaloric" cooling system; 20 C is very good for a magnetic system. For air conditioning, a delta of 25 C will just do (assuming outdoor temperature below 50 C!), but heat pumps may need to cross temperature gaps of 40 C or more.

Hydrocarbons work quite well and are (comparatively) minimal impact on climate change. There's been some paranoia about fires, particularly in automotive applications but it's actually a quite small amount needed to do the job.

The problem are large building air conditioning systems, grocery store chillers and industrial machines - they contain an awful lot of coolant and are very expensive to replace which means they tend to last for decades.

Ammonia (another dead simple molecule/process) is used in these services quite often, as far as I know.

From what I understand, at least here in Europe CO2 has been common in recent supermarket and similar installations.

One can buy large building air conditioners that use water to move heat around. There will still be refrigerant somewhere in the system, but there won’t be long refrigerant pipes anywhere.

I don’t know how popular these are. I have seen multiple condo buildings with a water source heat pump in each unit. The usual suspects (Mitsubishi, Daikin, etc) have hydronic systems with outdoor heat pumps on their websites. Chiltrix markets a small-building solution.

Why do centrifuges need refrigerant?

You probably have to sometimes spin biological materials that have to be kept cool.

Because they are temperature-controlled and contain a refrigeration unit.

In biological and medical applications, you might want to have the samples kept cool for stability. You'll transfer them from a fridge or on ice into the cooled centrifuge and back again after you've spun it down. Since in these big units the rotor is often a big hunk of anodised aluminium, it also helps maintain temperature stability.

Whats wrong with R600a (isobutane)?

It can provide heating/cooling suitable for nearly all usecases in homes, offices and retail (ie. -100C up to +150C).

It isn't awful for the environment if vented (no ozone depletion, greenhouse effect less bad than driving your car a few miles if you vent a fridge/freezer).

Yes, it is flammable... But in typical quantities in a fridge (perhaps 60 grams), it's hard to do too much damage.

It is also cheap, easy to lubricate, unpatented, made by many suppliers and efficient.

I really don't understand why anyone would want to use anything else....

Every flammable refrigerant I've seen is usually in a completely sealed system. There is no way to maintain them unless you completely vent the system and add ports yourself, manufacturers don't seem to want the liability and many governments force the issue by code anyways.

You typically need to completely vent the system for any maintenance on a refrigeration system anyway, if only for the fact it is important to weigh the amount of refrigerant (too much and you could get slugging, which is very expensive to fix).

I think lack of ports is simply to save money - in the factory it's just as easy to fill once and crimp the system closed.

> You typically need to completely vent the system for any maintenance on a refrigeration system anyway

On residential/small systems where it's commonly used today, sure. For larger systems this is not true. You're typically going to have a receiver and a valve you can use to store the charge entirely in the receiver. Then you can work on the system without having to dump or capture that charge.

It also allows you to have additional cooling circuits, so you're starting to see this incorporated into smaller commercial designs for the additional cooling efficiency.

> I think lack of ports is simply to save money

They're required to be hermetically sealed in the US by IEC and in most Pacific Island countries by law where they're more commonly used in residential applications.

Save money, and force consumers to buy a new one when it breaks

I'm not an expert in refrigerant selection but you've missed many critical aspects of a refrigerant: we care about viscosity, density, thermal conductivity, etc. because these all impact the energy efficiency of the system.

Several light hydrocarbons seem like perfectly good alternatives. Propane is another one. And there's also quite a lot of use of ammonia for refrigeration as well. It's not clear to me why these simpler, non-chlorinated, non-fluorinated compounds are so grossly undesirable that we keep chasing more-complex alternatives.

Is it really that people are simply horribly afraid of their flammability?

Ammonia is quite toxic. Some bad outcomes from leaky ammonia air conditioning in the past. Ok for industrial chillers with good leak detection systems.

Texas state code requires machine rooms for ammonia systems to get 30 air exchanges per hour, same state building code requires houses to be under 1/3 air exchanges per hour.

I'm a little fuzzy about the later, pretty sure about the former, and most people don't have the privilege of living in Texas (not sure if I'm kidding or not?), but it demonstrates the safety issue that ammonia cooling needs about a hundred times as much ventilation as a normal kitchen. And insert the usual quotes about building codes being written in blood so they aren't demanding a hundred times the ventilation just for fun.

People are scared of the sealed container explosion.

An external butane leak would be about as harmful as a leaking cig lighter.

Internal leak? A perfect mixture of butane and air the size of fridge would certainly take out a wall, maybe an entire house if it knocks out a load bearing wall.

The worst part about the internal explosion is its almost certain to happen when the owner is standing right in front and opens the door and the light kicks on along with maybe anti-frost heaters or whatever else is in there.

I have seen some ideas proposed such as using the "smart" in a smart fridge for good not evil and locking the door if the system pressure drops below "X". Much more likely the "smart" in a smart fridge will never be permitted to be used for anything other than advertising and marketing, which is sad.

Energy content of hydrocarbons is about the same (to one sig fig or less LOL) and just one gram of gasoline can blow a piston rod clean thru an engine block under perfectly bad conditions (already shattered bearings, etc) so a couple hundred grams under worst possible case in a confined sealed fridge could take out a house, most likely.

(Edited to add: I have a better analogy: A perfect stochiometric mix of air and diesel the size of my coffee cup can blow the engine head clean off a diesel engine, IIRC that's how one of the brothers who invented the Diesel engine died in a lab accident a century ago. And that was just a little coffee cup sized engine cylinder. So imagine a sealed container the size of a fridge instead of a coffee cup... that'll take out a house for sure... neighbors will "probably" live but I wouldn't bet on it...)

I had an internal explosion of my gas grill. I apparently forgot to turn the gas off so it filled the chambers under the grill plates and when I went to light it, it sent the top and the grill plates through the lanai and 40ft into the air. I lost my eyebrows for a few months.

locking might not even be necessary, just power off the device if pressure of refrigerant drop.

Having some way to ventilate the gas (so you don't just get "a box full of flammable gas" situation on slow leak) without reducing performance too much might help also

I get your point, but we already have methane pumped to our houses. Are these worse?

Yes, sealed container vs open air. If we stored natgas in scuba tanks that could get exciting... ironically there are people considering powering auto engines with compressed natgas... must be very exciting in a fire LOL.

Yet we plumb methane in houses all the time. Also, at least for HVAC, it's perfectly reasonable to keep all of the refrigerant outdoors and use water as a heat transfer medium to the interior.

And it’s not a great idea, especially given the proliferation of appliances that burn it in room air.

And methane has the convenience property of being less dense than air. I’m not sure, but I expect that the heavier hydrocarbon gasses might be more likely to accumulate indoors.

A3 refrigerants (hydrocarbons) have very low charge quantity limits that basically make them infeasible systems with even modest capacities. Split type air conditioners or heat pumps predominately used in the US have several times the allowable limit of charge in the liquid line alone.

Building codes have only recently (and incompletely) been revised to allow mildly flammable refrigerants (A2L) inside most buildings for space conditioning. Amending these for A3 refrigerants is an uphill battle.

Ammonia is mildly flammable, toxic, and electrically conductive. Good luck finding/building a hermetically sealed compressor that is anywhere near affordable.

CO2 in a refrigeration cycle goes transcritical at even moderately warm temperatures, making the system very inefficient without adding several (typically expensive) changes to the cycle. Manufacturers would struggle to build a CO2 air conditioner that meets minimum efficiency standards at anywhere near current equipment costs.

Flammable refrigerants are no joke:

https://www.youtube.com/watch?v=A169-s4KHFQ

For better or for worse, people like to pump refrigerant through pipes in buildings, and flammability can be a problem. Also this requires a lot of refrigerant.

One can separate the refrigeration part and the moving-heat-around part, though, by using good old H2O in pipes. Water is non-flammable, non-ozone-depleting, cheap, and has zero GWP. It can be a bit messy if a large amount spills indoors, though.

Is it time to admit that maybe the problem with r22 and some of the other CFC's were that people were using them as propellants for hairspray/etc, as canned air, and any number of industrial processes (packing peanut manufacture) that was basically blowing it into the atmosphere and the lack of regulations requiring refrigeration units to be repaired/leakchecked before pumping more refrigerant into them?

It seems pretty clear that the fairly short lived damage they cause to a renewable resource (ozone) would largly be a non issue given modern refrigerant regulations. While the advantages make them pretty much the best in any number of areas.

You are following the explanation for the bans as they are told.

R134a was introduced in the 90's, and in 2010's it conveniently is named bad at the same time the patent runs out.

So the savior was the 4x as expensive R1234yf, introduced 2012. Don't worry that it's flammable.

Here we are 10 years after R1234yf, it's time to explain why it can't be used anymore!

While we were waiting for a contractor to replace our failing AC and furnace, he had to come back like four times to recharge the system (supply chain issues getting the new unit). Now I wonder how much refrigerant we were unintentionally breathing, and how much PFAS we were bio-accumulating during that time.

If you read that article carefully you probably don't have PFAS in your system. It would have to have been replaced in the last 10 years to possibly have it.

The older stuff had HFCs/CFCs but didn't have PFAS.

I am in the same situation. My system has had to be recharged every 2 years or so but has not failed yet. Overall we're talking very small amounts leaked on mine.

I wouldn't worry about it, these gasses are included in the blanket PFAS classification, but they are fundamentally different and thus non-toxic. r134a, a common refrigerant, and likely what your system uses if it's less than 10 years old, is used in inhalers.

> r132a, a common refrigerant

Are you thinking R134A? IIRC, R132A theoretically exists but nobody makes it. And R134A is an automotive refrigerant. Most residential systems in the last 10 years likely use R410A (which is itself a mixture of R32 and R125). That is getting phased out and generally replaced with plain R32, as far as I know.

R32 is also on its way out, and new units here in Europe tend to come with R290 (propane)

I have heard a lot about R290 but at least in the US, I am not seeing much of a push to go there. R32 is an A2L refrigerant and (according to the article) isn't affected by the PFAS ban. In the US at least it looks like the main choice for the future, at least in the near term.

That's interesting, a had an AC unit installed 2 years ago (in Europe), and then many units were marketed as using the new R32 instead of the traditional R410A.

Now that I look at the website of the company that did the installation, it seems all their AC models now use R32.

Sorry, 134a yes

Then why are they banning R134A as the article says?

Glaxosmithkline loves it when they do this, it allows them to create a new propellant forumlation, and then that allows them to put basic asthma medication back on patent.

And the current R134a patents are just set to expire. Inhalers which should cost $5/ea are set to be $90/ea again.

This is the same thing they did when CFC were banned and they switched from CFC to R134a. This is a medication that should have been off patent decades ago, but due to this "trick", it almost certainly never will be.

> R152a also falls outside the PFAS definition.

Oh, so it might be possible to use the contents of "canned air" gas dusters as refrigerant.

Yep. Turn one of those cans upside down and spray it, and you'll see how that works very quickly.

PFAS are harmful, both to the environment and humans, so the transition to safer alternatives is commendable.

The fact that this ban seems to fit the specific blend of a particular company, however, casts some doubts on how this process was conducted. Specially in a time when demand is projected to increase considerably.

at some point this kind of luddism will become self-defeating; we can only hope that it doesn't engulf the whole human race

this is banning the safest refrigerants, forcing either a switch to dangerously inflammable refrigerants or to systems without refrigeration

Banning harmful substances isn't luddism. What do you think luddism is? What is the harm of this ban?

You know why these substances exist right? Because the prior substances were cutting a hole in the ozone layer. And at the time the new-then substances weren't proven bad yet.

And those ozone eating substances themselves came about because the prior refrigerants were more flammable or poisonous and the then-new substances were not yet proven bad.

It's an endless game of whack-a-mole.

I don't think any of this is alarming. Nor a reason we should stop trying to solve new problems as we learn of them.

I'd rather be exposed to the known-known of propane refrigeration in my consumer devices (car, window unit, refrigerator, mini-split, etc) than risk exposure poorly understood chemicals to reduce the chances of a refrigerant fire from one tiny decimal per capita per lifetime to a slightly smaller tiny decimal per capita per lifetime.

It sounds like an endless march of gradual forward progress, since each generation of refrigerants has been less destructive that the one before.

the refrigerants that will still be allowed are literally the ones used in the very first vapor-compression refrigerators in the 19th century: blends of light alkanes, called 'chimogene' at the time; see us patent 87,084 from the year 01869 for example

these (and sulfur dioxide) are what cfcs were invented to replace because they were dangerously inflammable

if your 'endless march of gradual forward progress' ends up where it started after a century and a half of 'progress' i really question your definition of 'forward'

> You know why these substances exist right? Because the prior substances were cutting a hole in the ozone layer.

Refrigeration may end up back where it originally started (before freon even), using ammonia. Ammonia is somewhat dangerous on a local level (you don't want an ammonia leak in your house..) but AFAIK it doesn't eat up ozone and the local hazard is something that can be mitigated with the right sort of product design.

> Ammonia is somewhat dangerous on a local level

Like saying that the Ohio train disaster may cause lung irritation, that quite undersells the problem.

Ammonia refrigeration is inherently dangerous and has been banned from domestic refrigerators for a long time for good reason. Some regulations are written in blood.

I think it could be possible to use ammonia in domestic refrigerators safely if appropriate measures were taken. Particularly, require that refrigerators be installed with vent pipes leading from a tamper-resistant enclosure straight to the outside. Such vents would be similar to those used in waste plumbing to protect people from toxic sewer gasses like hydrogen sulfide: https://en.wikipedia.org/wiki/Drain-waste-vent_system

But jabl is probably right and something like propane would make more sense.

I don't think we'll see ammonia used in domestic refrigeration. Industrial use, sure.

I think what we'll see for domestic refrigerants (refrigerators, AC, heat pumps) is hydrocarbons like propane or butane (already a reality for refrigerators in most of the world), and in some cases CO2.

i went to a hotel with an ammonia refrigerator in the kitchen a couple of weeks ago

Yeah, ammonia is very common in industrial refrigeration, especially big specialized systems that need tons and tons of refrigerant, as illustrated by this famous accident in which 30,000 lb. of the stuff was released:

https://www.csb.gov/millard-refrigerated-services-ammonia-re...

this was a 60-liter fridge with 117 grams of ammonia in it in the kitchen of the hotel suite

How do you feel about leaded gas?

> How do you feel about leaded gas?

I think it should be banned.

Sadly, aviation has enough political muscle that they're still allowed to use it. Which is amazing to me, given lead's extremely harmful effects.

Do you really think the people flying their small cessna with 100LL have so much political muscle? I strongly doubt so.

It's not the pilots alone, it is also the piece-of-shit-airplane industry which employs a handful of people here and there, enough to have a little suction in Congress.

Also GA is, in the end, a relatively small-scale activity, so leaded avgas isn't much of a public health hazard like leaded automotive gas was back in the day. More of an occupational hazard for people working on and flying those planes, and higher maintenance requirement on the engines.

Hopefully they can manage to roll out G100UL at scale so 100LL can finally die. And then that final TEL plant on the planet can be shut down for good.

Let's not forget those small airports where nearby residents are at higher risk due to leaded avgas. That's why small airports have been forced to close.

Get rid of leaded avgas and we can have less municipal airports closures.

The general aviation industry is protected because it's part of the pilot training pipeline, and that is important because airplanes (both commercial and military) have a great deal of importance to governments. About 5% of the American GDP is attributed to commercial aviation. Compare that figure to the number of deaths caused by leaded avgas, and you don't need conspiracy theories to explain the outcome.

> Sadly, aviation has enough political muscle that they're still allowed to use it.

Does it? GA is a shadow of its former self.

There's already a substitute. But it's precisely how small general aviation has become that's stifling the transition. The volume of avgas made today is already pretty small, compared to other gas users, and there's ony a handful of plants that can make it. Then there's all the small airfields with existing avgas pumps.

Without a big push, it will take time. The fastest way would be with a carrot; the stick can come later.

leaded gas should be limited to extremely low-volume applications, because it's enormously harmful

this regulation is more like banning unleaded gas

There are better octane boosters, the only reason lead was used was because it was marginally cheaper.

But it's not like unleaded gas. Evidence has been mounting that PFAS are the modern 21st century's lead, hence bans like this.

privacy invasion and this kind of discourse are the 21st century's lead

there are pfas that are pretty bad but the refrigerants in question are not among them

Snark doesn’t do anything but virtue signal.

i think it's a reasonable question directed at clarifying their understanding of my position

or anyway a person who wanted to clarify their understanding of my position could very reasonably ask that question

The meta goal of greenwashing means you can't use Peltier coolers as it would take insane amounts of power to replace a condensing fridge, like dedicated circuit 15 amps. They're very inefficient... if you're burning coal. What if you're not burning coal?

Consider this loophole... imagine a crappy anti-green energy wasting Peltier cooler connected to a solar panel. Half the day it chills down to -70C and then all night long it slowly warms up to -50C until sunrise. Probably the bottom quarter of the fridge is a giant ice block with fans blowing on it when the fridge above warms up, whereas the cooling is solar and below and is on full blast whenever the sun is up.

Minor problem is now you're dumping 1500 watts of heat into your kitchen whenever the sun's up. Nice in the winter, not so much in the summer. And some idiot is going to gain access to the cold-sink to "chill their vodka" and end up with frostbite when they touch the -70C sink. And good luck periodically defrosting that beast. But, in general, its not an overly crazy idea.

No, it is utterly terrible solution, as even the worst refrigerant beats peltier coolers.

My point is even the best refrigerant powered by coal or even "rando outlet power on average" is less green than the worst Peltier cooler powered by a solar panel. So as per OPs original claim that if we ban every chemical more hazardous than distilled water we can have no refrigeration is not entirely true, we can in theory redesign the entire system around not using any refrigerants.

It would be an environmental disaster if not powered by solar, or maybe wind, of course, but it would technically work.

Well, no, coz you can use refrigerant like CO2 and that could be taken from atmosphere.

i agree that tecs are a plausible solution for some applications, and i have in fact lived in a house with a small tec-driven refrigerator, but phase-change energy storage or tces are more viable solutions to the daily energy storage problem than the sensible-heat energy storage approach you suggest, among other things because the large ΔT you suggest would entail an absurdly large stack of tecs

you can solve the waste heat problem by putting the tecs outside and running a coolant loop through the wall, filled with brine or propylene glycol; in the case of pces, the chilled coolant from the tecs freezes the ice inside your kitchen, in the ice reservoir which is used to cool the icebox

tces systems (not to be confused with tecs) can be driven directly by solar heat rather than through pv

however, i am not convinced that tecs are a viable alternative to vapor-compression refrigeration in general

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