Freeze on refrigerants heats up search for replacements

The world has agreed to begin phasing out hydrofluorocarbons (HFCs), whose greenhouse effect is 10,000 as strong as carbon dioxide. Nearly a year after the 197 signatories to the Montreal Protocol started work on an agreement covering HFCs, 170 countries have cut a binding accord to farewell the gases. HFCs turn up in …

[Pangasinan]

Liquid CO2?

I learnt at school that CO2 went from frozen solid to gas with no liquid stage.

So will future Coolers/Freezers manage a solid refrigerant instead of liquid?

But a lot may have changed since the 1960's

[John Geek]

Re: Liquid CO2?

CO2 will liquify under sufficient pressure (a bit over 5 atmospheres)

[John Geek]

one of the best refrigerants is.... Propane. you can drop it right into an existing R12 system and it works just fine, better than R12 to R134a conversions, even.

[Anonymous Coward]

However it's not quite as effective a replacement for HFC's fire suppression role.

[Anonymous Coward]

Why not, then the fire can burn itself out more rapidly :)

[Voland's right hand]

Newer refrigerators use pentane

Plain hydrocarbons are perfectly fine as refrigerants. My new small fridge runs on Pentane. They are, however, quite strong greenhouse gases (as noted by the article).

IMHO the worry about "greenhouse emissions from refrigerating equipment" are a bit of a red herring. The amounts of hydrocarbons left into the atmosphere as a side effect of gas and oil mining and refining are orders of magnitude more than the effects of hydrocarbons used as a refrigerant on the environment.

What the article misses to say is some of the side effects. While domestic equipment rarely needs top-up and refill nowdays, cars' aircon does. They are also not rated for non HFC replacements. This is effectively a form of planned obsolescence on all pre 2016-ish vehicles in ~ 5 years in the warmer part of Europe and USA. So I am definitely topping mine up next year in all vehicles regardless of do they need it or not.

[Oengus]

Re: Newer refrigerators use pentane

I was looking at my car the other day and it was pointed out that it still has R12 and the aircon still works. Guess I won't be changing it any time soon...

[Ole Juul]

Re: Newer refrigerators use pentane

Propane is a direct drop-in for R12 and you can use it safely in your car. See here. Lots of people are doing it. A licensed person probably can't do it, but you can do it yourself or use an intermediate refrigerant to circumvent the law - this will depend on country.

There is a lot of FUD on this topic. I suspect that it is both political and emotional. I note that the ones crying fire/danger are not generally experts and in fact refrigerative engineers think propane (sold as R290) is just fine. Here is an article from actual experts: Propane as R22-Replacement in Commercial Appliances

What the FUDsters (fudtards?) don't seem to know is the basics. Propane has a very narrow flammability limit. In fact 2.15 and 9.6% of the total propane/air mixture must be propane in order for it to be combustible. If you are outside of this range, it won't burn. It is an exceptionally safe gas. Appliance engineers calculate the amount of propane in a refrigerator and look at what mixture you would get in a small kitchen if all the propane got out at once. This would be an extremely rare event but even then you could not have a fire or explosion because there is not enough propane to make a flammable mixture.

I'm thinking that there might be some economic and control issues somewhere in the supply chain regarding traditional refrigerants. Bringing up the fear of fire and explosion is an effective way to stop people considering this gas - even though the scientific facts show them to be lying.

[PNGuinn]

Re: Newer refrigerators use pentane

The slight problem with propane is its density. It's much denser than air and will hug the ground, enter drains etc. That's why there are strict regulations regarding the location of LPG (propane or butane) storage and LPG burning appliances. That is likely to be a problem in many cooling applications.

[beerfuelled]

Re: Newer refrigerators use pentane

Having a quick look at the (UK) guidance, it looks like it only applies to new cars. Reading between the lines I guess that means it will still be okay to top up existing cars. I've only skim-read it though so may be wrong!

[joed]

Re: Newer refrigerators use pentane

It may be OK to top of existing cars but once the production ceased in 2018 the refill will become hard to get (and expensive).

[Anonymous Coward]

It is CO₂, not CO²

Title says it all.

Quick, somebody call a taxi - I am late for my meeting of Chemists Anonymous.

[Buzzword]

Re: It is CO₂, not CO²

Superscript digits 1, 2, and 3 were included in character sets Windows-1252 and ISO-8859-1, whereas subscript digits are only available in Unicode. Historically, a lot of email and content-management systems stuck with the old character sets. Even today some fonts don't include the subscript digits. When in doubt, stick with what works. Readers understand that CO² = CO₂, even if it's semantically incorrect.

[J.G.Harston]

Not related to most HFCs going out of patent?

[Dieter Haussmann]

Someone's (DuPont?) patent just ran out.

[9Rune5]

DuPont wouldn't happen to have a patent on a possible replacement gas now, would they..?

[Charles 9]

I wonder if part of the problem is that the very properties that make a substance a good refrigerant also make it a greenhouse gas?

As for propane, what about at the point of a leak, which would not only be more concentrated but also likely to trigger static sparks. IINM, this caused a massive fire involving lots of cylinders one day.

[Chemist]

"the very properties that make a substance a good refrigerant also make it a greenhouse gas?"

Any substance that has a bond capable of absorbing infra-red is going to be a greenhouse gas of some level of potency. A further important factor is the substance's half-life in the atmosphere & indeed the potency & half-life of the break-down products.......

[Richard Simpson]

Ongoing maintenance

Has anyone found a clear explanation of what this means for the maintenance of existing equipment (e.g. the air con in my cars). Should I stock up on bottles of HFC?

[Phil O'Sophical]

Re: Ongoing maintenance

e.g. the air con in my cars

Just make sure you use it regularly, even in winter. It's not only useful (stops the car misting up) but will prevent leaks. A big cause of loss of refrigerant in a car is that people don't use the air con in winter, and the seals dry out & leak.

[CrazyOldCatMan]

Re: Ongoing maintenance

people don't use the air con in winter, and the seals dry out & leak.

I had this in my car. The garage just suggested that I get it refilled, come back in a week or so and they would check for where it was leaking.. (so costing me double).

I still have *some* gas pressure (aircon works but not well - I have it on most of the time now). Do the seals restore themselves once you start using it again? Is it worth getting it refilled and carrying on using it?

[CrazyOldCatMan]

Re: Ongoing maintenance

On cars over ~8 years old, you need to strip all of the air-con components

It's a 2007 FR-V..

Oh well. It's not like we have enough hot days in a year to justify the cost of fixing it. The whole car is probably only worth £4k (2007 1.8 VTEC auto-box FR-V, 60K miles, some slight distress to one body panel..) so spending £600 (which was what I was quoted for replacing the seals) probably isn't worth it.

[Sgt_Oddball]

Re: Ongoing maintenance

That'd be why I've not bothered at all on my 2003 corolla. Air con stopped working 2 years ago but it's never been replaced so the seals will be shot and getting it fixed would be worth more than the car (I've also got 118k miles on the clock on a petrol engine so it's a case of running it to the ground until I can justify a new car)

[Sleep deprived]

Re: Ongoing maintenance

My mechanic once told me that in the old days, when the air con had its own engageable belt, seals and pumps lasted longer. Now that engines have a single belt to run everything, the air con pump is always running, although idle, thus wearing seals and pumps faster and causing more greenhouse gas leaks.

[druck]

Re: Ongoing maintenance

Even with an single belt, an electronic clutch can be used to ensure pump doesn't run all the time.

[Down not across]

Re: Ongoing maintenance

Now that engines have a single belt to run everything, the air con pump is always running, although idle, thus wearing seals and pumps faster and causing more greenhouse gas leaks.

I don't see what single vs multiple belts has to do with it. All cars I've had (both with multiple and single belts) have had clutch on the AC compressor. The compressor only runs when the clutch engages. The pully will always spin whether single or multiple belts.

[JeffyPoooh]

Drop-in replacement, or vast (destructive) implications...

RS asked about 'the air con in my cars'.

If a drop-in replacement refrigerant isn't agreed, then one can imagine that many millions of cars and/or zillions of appliances might be scraped before their time. As if that massive waste (scrapping durable goods before their time) wouldn't itself cause a spike in emissions (good for the economy, very bad for the planet).

I've read elsewhere that the German car makers aren't very impressed with the slightly-flammable replacement (HFO-1234yf).

I don't mind to retrofit a new compressor under the bonnet (hood) of my car, but any requirement to tear the dashboard apart leads to the early death of a car.

I'm not convinced that this approach is optimized. Unless they agree on a drop-in replacement.

Hopefully somebody has a plan.

[JeffyPoooh]

Re: Drop-in replacement, or vast (destructive) implications...

Anyone care to explain their down votes?

My working hypothesis is 'Airhead Environmentalism', where the Ecomentals will happily scorch the planet to achieve their lower-order intermediate environmental milestones.

The point is that it might be a wise approach to abandon the Eco Milestones As A Religion approach to achieve a MORE OPTIMUM overall result.

Perhaps others, those planet killing ecomentals, wish to take a less optimum approach?

I'm open to correction if I've missed something.

[a_mu]

why refrigerants ?

Heat pipes move heat without refrigerants,

and solid state peltier coolers move energy from low state to high state ( a heat pump ),

cost ? make more and cost goes down .

efficiency , may be,

[Gene Cash]

Re: why refrigerants ?

Heat pipes don't move much heat. Peltier efficiency is in the 10% range.

Neither are very expensive, they're just shite at what they do.

[Charles 9]

Re: why refrigerants ?

Actually, most heat pumps still need refrigerants. It's just they're designed to work in either direction: transferring heat outside in the summer (acting like an A/C) and inside in the winter (acting like a heater). You still need a means to transfer the thermal energy form place to place, and that's where the refrigerants come in.

Also consider that a car engine itself gets pretty hot, even in the winter. That's why many car heating systems simply pass air around the engine before sending it into the cabin (and thus why the heat doesn't really work in a car until after the engine warms up, unlike the A/C which can usually get to work within a few seconds of the car cranking up).

This also poses a problem for the Peltier cooler since the hot and cold sources change from season to season.

[JWLong]

Automotive A/C - The Story

The main loss of refrigerant in a cars A/C is loss at the compressor. The reason being is that the compressor is externally driven (not hermetically sealed). This drive consist of a shaft with a seal and an electric clutch.

In the winter time when the A/C is never called for, the compressor is cycled on and off intermittently when you use the windshield defrost control. This function also keeps super hot air (180 Degrees) from blasting the glass when it is cold and cracking it. Remember now, there is only one air handler (fan) and two coils in a vehicles climate control system. Much like your central air system at home, and the cooling coil is always the second one in line of the air flow.

The above cycling of the A/C system in the winter keeps the shaft seal lubricated and pliable so that it retains the gas in the otherwise sealed system. If you listen, in the winter you can hear the control system cycling the electric clutch on the compressor on and off during defrost to temper the air going to the windshield, yet the air going to the rest of the interior of the vehicle will be at maximum temperature selected.

[Anonymous Coward]

Re: Automotive A/C - The Story

Great explanation, but missing one thing, the A/C doesn't run during defrost to prevent cracking the glass (otherwise old cars, or new cars with dead A/C, would be cracking windshields all winter). It runs so that you don't have warm humid air hitting a cold surface,which would kind of do the opposite of clearing a foggy windshield. The cycling keeps from overcooling the air, or freezing the evaporator coils.

Didn't know about the compressor being the leading area of loss, makes sense.

[David Pollard]

Margaret Thatcher

Though I was far from being one of her supporters, she deserves to be remembered for the good work she did in getting the Montreal Protocol internationally agreed and for persuading her chum Ronald Reagan of its relevance.

Perhaps we need more politicians who have some understanding of science.