R-134a going the way of R-12

I've got an R12 car that I've been nursing along, but I think it's time to bite the bullet. The car has a very, very slow leak somewhere so I need to recharge it with about 8 oz of R12 once a year. I actually have a NIB 134a compressor that I can swap in.

What's the best thing to do?

In reply to Keith Tanner:

Its like anything else. There's bad, good, better and the correct way of doing it. Which do you prefer?

bravenrace wrote: In reply to Javelin: I'm on the SAE subcommittee that oversees this issue, but I guess you know better than me...

Is there anything you don't do?

I buy from every supplier to the North American market, none of which offer r1234yf yet, or have announced plans to, or have announced a reduction in r134a. We have had multiple releases about propane as a possibility. But hey, they only manufacture and sell the stuff, what do they know?

bravenrace wrote: In reply to Keith Tanner: Its like anything else. There's bad, good, better and the correct way of doing it. Which do you prefer?

I'm fine with correct. Particularly when it coincides with most effective.

Javelin wrote:

bravenrace wrote: In reply to Javelin: I'm on the SAE subcommittee that oversees this issue, but I guess you know better than me...

Is there anything you don't do? I buy from every supplier to the North American market, none of which offer r1234yf yet, or have announced plans to, or have announced a reduction in r134a. We have had multiple releases about propane as a possibility. But hey, they only manufacture and sell the stuff, what do they know?

See, I knew you would know better than me! Although I don't know where you got the idea that I said 1234 was available now. Its in development, and has been for quite a long time.

So was the peterbuilt co2 unit too big for a car? Why was it built into a truck? Can an r12 unit be home converted?

Keith Tanner wrote: I've got an R12 car that I've been nursing along, but I think it's time to bite the bullet. The car has a very, very slow leak somewhere so I need to recharge it with about 8 oz of R12 once a year. I actually have a NIB 134a compressor that I can swap in. What's the best thing to do?

And hence the reason for my post a couple of weeks ago about retro fitting my truck. My leak is real real real slow.

Keith Tanner wrote:

bravenrace wrote: In reply to Keith Tanner: Its like anything else. There's bad, good, better and the correct way of doing it. Which do you prefer?

I'm fine with correct. Particularly when it coincides with most effective.

If you look at it in terms of performance, there is no way to actually do a conversion that will have equal performance. That would require changing every component, which at that point really isn't a conversion at all. But I'm sure you already knew that.
The most important factors in doing a good conversion is to get rid of all the oil mineral oil and any parts that will either absorb the oil or allow the refrigerant to escape.
The first thing to do is completely flush the system. One of the most important things is to get rid of all the oil, because it's not compatible with the oil used with 134A systems. To do that, you need to not only flush the system, but replace the drier and the hoses, as they both absorb oil and the hoses need to be changed to 134A compatible hoses. Also change the o-rings to Buna-N or similar. Then manually clean the condenser, evaporator and compressor. If you have a 134A compressor, that's even better. Add the appropriate amount of the correct oil for whatever compressor you are using. Can you do a conversion without changing all these parts? Sure, but you risk the chance of a pre-mature compressor failure if there is too much of the old oil in the system.
Then re-assemble the system and do a VERY complete evacuation. I error towards overkill on this, because removing as much of the oil, water, air, and contamination has such an effect on performance.
Evacuate to 1000 microns, then continue to evacuate for 30 minutes after that. let the system sit static for 10 minutes. The reading should not rise above 1500 microns in this time. If it does, then there is still moisture in the system or a leak. Evacuate for another 15 minutes and again let it sit. If it rises again, then there's a leak. Once you know the system is sealed, you can charge it. Use adapter fittings on the charge ports. It will likely not take as much refrigerant as it did with R-12 without creating excessively high pressures, which is one of the reasons why it also won't cool as well. But it should cool sufficiently. If the system has a sight glass, use it to gauge the charge. When it becomes clear you are usually in the range you need to be.

itsarebuild wrote: So was the peterbuilt co2 unit too big for a car? Why was it built into a truck? Can an r12 unit be home converted?

Because my company does systems for heavy duty trucks, ambulances, fire trucks, busses, and off road construction and farming equipment. We just don't do cars.

Thanks Bravenrace. I don't know much about AC, so that's the sort of info I needed.

Basil Exposition wrote: Can't wait. Mucho excitement in store with more explosive gas solutions being imported from Mexico again.

Yeah man. I remember those days... also FWIW, R1234a is 'mildly flammable'. Sorta like being a 'little pregnant', I guess.

So what is the EPA proposing we replace R-134a with for automobile use? Isn't HFO-1234yf that stuff that's highly flammable?

Keith Tanner wrote: Thanks Bravenrace. I don't know much about AC, so that's the sort of info I needed.

Any time you have a question don't hesitate to ask.

Sky_Render wrote: So what is the EPA proposing we replace R-134a with for automobile use? Isn't HFO-1234yf that stuff that's highly flammable?

Its flammable, but not as flammable as most other alternatives. The flammability issue has been blown way out of proportion due to politics, greed, and corruption. Right now it's still the refrigerant that everyone in my industry is working with.

But CO2 is a green house gas remember.

This is pretty funny because if you capture c02 from the atmosphere and stick it in a refrigerant system you're actually doing 'carbon sequestration'.

Of course, you'd have to charge a lot of AC systems to make up for the carbon de-sequestration i do every year when i burn all the tree branches that fell down.

bravenrace wrote:

Sky_Render wrote: So what is the EPA proposing we replace R-134a with for automobile use? Isn't HFO-1234yf that stuff that's highly flammable?

Its flammable, but not as flammable as most other alternatives. The flammability issue has been blown way out of proportion due to politics, greed, and corruption. Right now it's still the refrigerant that everyone in my industry is working with.

I don't really care its flammable, I care that when it burns you get a lot of fun fluoride compounds. http://www.en.uni-muenchen.de/news/newsarchiv/2014/kornath_refrigerant.html

bravenrace wrote:

Sky_Render wrote: So what is the EPA proposing we replace R-134a with for automobile use? Isn't HFO-1234yf that stuff that's highly flammable?

Its flammable, but not as flammable as most other alternatives. The flammability issue has been blown way out of proportion due to politics, greed, and corruption. Right now it's still the refrigerant that everyone in my industry is working with.

Blown out of proportion? How so?

http://www.r744.com/articles/span_style_color_rgb_255_0_0_updated_span_daimler_video_claims_1234yf_is_dangerous-vw_says_co_sub_2_sub_is_best_refrigerant

I'm not trying to be an ass; I'm genuinely curious, since that video seems to show that R-1234yf + hot engine parts = fiery death.

Not exactly an unbiased source, there, Sky.

Sky_Render wrote:

bravenrace wrote:

Sky_Render wrote: So what is the EPA proposing we replace R-134a with for automobile use? Isn't HFO-1234yf that stuff that's highly flammable?

Its flammable, but not as flammable as most other alternatives. The flammability issue has been blown way out of proportion due to politics, greed, and corruption. Right now it's still the refrigerant that everyone in my industry is working with.

Blown out of proportion? How so? http://www.r744.com/articles/span_style_color_rgb_255_0_0_updated_span_daimler_video_claims_1234yf_is_dangerous-vw_says_co_sub_2_sub_is_best_refrigerant I'm not trying to be an ass; I'm genuinely curious, since that video seems to show that R-1234yf + hot engine parts = fiery death.

and what is the result of the 15+ gallons of gasoline that are hauled around in a car when it meets an ignition source?

If you read the EPA documents, one of the alternatives they discuss for refrigeration units and home cooling units (NOT auto use) is propane. Another is isobutane. Talk about flammable. I was discussing this with my boss when he pointed out the fact that most people have a 30lb propane cylinder mounted directly under a live firebox on their wooden deck.

So, yeah, in comparison I'm not sure the flammability risk is that big a deal....

RossD wrote: R-410a is a popular refrigerant in HVAC equipment.

And it sucks compared to r22. Its a mix of compounds so it can only be charged as a liquid (much harder to get an accurate charge) it also runs at much higher pressure. Higher pressure= more leaks.

ultraclyde wrote: If you read the EPA documents, one of the alternatives they discuss for refrigeration units and home cooling units (NOT auto use) is propane. Another is isobutane. Talk about flammable. I was discussing this with my boss when he pointed out the fact that most people have a 30lb propane cylinder mounted directly under a live firebox on their wooden deck. So, yeah, in comparison I'm not sure the flammability risk is that big a deal....

I "might" know someone, somewhere, with a R-22 heat pump, charged with propane, cooling/heating their shop. It "might" have been running for a couple of years now, without bursting into flames. It "might" even cool/heat much better than it did when it was full of R-22. Since it's not a approved refrigerant, I'm probably confused and don't know what I'm talking about.

The person in question "might" be collecting parts to build a remote heat pump, using propane, to heat/cool a house without actually having propane piped inside. A liquid/liquid exchanger and a brine solution piped to all the rooms with liquid/air exchangers and thermostats...Hmmmm... Pretty sure that project is still in the planning stage though.

As a plus, propane operates at a lower pressure than R-22 so the compressor doesn't work as hard or draw as much amperage.

In reply to Toyman01:

That sounds like it 'might' be pretty interesting.

Toyman01 wrote:

ultraclyde wrote: If you read the EPA documents, one of the alternatives they discuss for refrigeration units and home cooling units (NOT auto use) is propane. Another is isobutane. Talk about flammable. I was discussing this with my boss when he pointed out the fact that most people have a 30lb propane cylinder mounted directly under a live firebox on their wooden deck. So, yeah, in comparison I'm not sure the flammability risk is that big a deal....

I "might" know someone, somewhere, with a R-22 heat pump, charged with propane, cooling/heating their shop. It "might" have been running for a couple of years now, without bursting into flames. It "might" even cool/heat much better than it did when it was full of R-22. Since it's not a approved refrigerant, I'm probably confused and don't know what I'm talking about. The person in question "might" be collecting parts to build a remote heat pump, using propane, to heat/cool a house without actually having propane piped inside. A liquid/liquid exchanger and a brine solution piped to all the rooms with liquid/air exchangers and thermostats...Hmmmm... Pretty sure that project is still in the planning stage though. As a plus, propane operates at a lower pressure than R-22 so the compressor doesn't work as hard or draw as much amperage.

i might know someone that's been thinking about trying propane in the AC system of a mid 80's turbocharged Buick product if he ever bothers to figure out where the system leaks..

novaderrik wrote:

Toyman01 wrote:

ultraclyde wrote: If you read the EPA documents, one of the alternatives they discuss for refrigeration units and home cooling units (NOT auto use) is propane. Another is isobutane. Talk about flammable. I was discussing this with my boss when he pointed out the fact that most people have a 30lb propane cylinder mounted directly under a live firebox on their wooden deck. So, yeah, in comparison I'm not sure the flammability risk is that big a deal....

I "might" know someone, somewhere, with a R-22 heat pump, charged with propane, cooling/heating their shop. It "might" have been running for a couple of years now, without bursting into flames. It "might" even cool/heat much better than it did when it was full of R-22. Since it's not a approved refrigerant, I'm probably confused and don't know what I'm talking about. The person in question "might" be collecting parts to build a remote heat pump, using propane, to heat/cool a house without actually having propane piped inside. A liquid/liquid exchanger and a brine solution piped to all the rooms with liquid/air exchangers and thermostats...Hmmmm... Pretty sure that project is still in the planning stage though. As a plus, propane operates at a lower pressure than R-22 so the compressor doesn't work as hard or draw as much amperage.

i might know someone that's been thinking about trying propane in the AC system of a mid 80's turbocharged Buick product if he ever bothers to figure out where the system leaks..

Another plus to propane is the propane molecules are a good bit larger than R-12 and R-22. Some systems that leak with the real stuff, don't leak with propane in them. Add in that systems are less likely to leak when the pressures are 20% lower.