Ice cold A/C

words of wisdom


I am so anti 134 in an R12 car that even I can't stand myself for it...

 

G'day Blokes,
I see you two are in America. I take it that R12 is relatively available?. Great. Here in Australia R12 is just not available.
If it was then it would be horrendously expensive. I have just checked ebay America and I see some cans for sale but customs here would go into massive melt down if I was to try to bring some in. They would probably send in the entire police force to incarcerate me for such a massive crime, such is the state of affairs here.
Now, what do you propose I use?.

Phelps.

 

For similar reasons in the UK there's a compromise product : R22

 

My 328's ac works fairly well. When I bought the car in Las Vegas I mentioned on this site that it had just been recharged with R12. But I was wrong and had misunderstood the tech I guess. It had been converted some years previously to 134 and I found the service papers for that. This was verified here in MD when I took the car to be inspected after arriving.

The car has an oem-appearing York compressor though there is also a service record that it was a rebuilt replacement in the late 90's. Perhaps it was replaced in conjunction with improving the function with 134? I don't know. With other than direct sun into the windshield, the controls need to be run at lower settings or it is too cool in the car. WITH direct sun into the windshield and high temps, the ac is fair but not great. The air temp coming out of the vents is very cold but by the time it gets up that windshield/black dash, it is considerably warmer and the compressor continues to cycle on/off even at the max setting.

Based on US ac units of the era that used the same compressor and would freeze you out of the car, it seems to me that with the setting at max cool, the compressor should stay on constantly - or at least a lot longer than it does. I assume there is a temp sensor mounted on the evaporator that triggers the compressor; maybe the sensor is too close to the evap outlet or it is in need of replacement. If the compressor ran constantly on the MAX setting, the car would be as cool as you want it even under the warmest conditions. The fact that it cycles is what makes it not a good as it should/could be.

 

Assuming that the system is charged as it should be, the compressor cycles because the evaporator is too small and/or the fan is too weak for adequate heat exchange. The pressure sensors detect when there is not enough heat being added to the freon and cycle the compressor as necessary to keep it from damaging itself or the system.
Constant cycling can be an indication of the wrong amount of freon in the system - too much or too little.

 

Ship it to OZ and bring it in by boat?

 

I converted my 77 GTB to R134 with a new Sanden compressor recently. Actually, I ran R12 in the new Sanden for a couple years, then switched to 134 a few months ago. Surprisingly, the 134 blows much colder...!

Greg

 

Please define 'constant cycling'. What would the frequency be?

 

If 134 is colder now I would suspect that it is because the previous setup with 12 was low on charge

 

"Constant cycling can be an indication of the wrong amount of freon in the system - too much or too little"

Since the system was just serviced and recharged before leaving Las Vegas and it functioned the same way on the entire 2700 mile trip and continues to do so here, I'd ASSUME (Yes, I know about assumptions) that the quantity of 134 is correct. I may do a little research into this cycling thing since I'm certainly no ac expert! In some internet research so far, it appears that cycling is normal regardless of setting. Some auto a/c units cycle on with "on" times considered OK if they are not less than 15 seconds at a time.

I was basing my thought that it shouldn't cycle at all on some ac units I remember that would ice up the evaporator if you left them on max for a long period. I guess the cycling is to ensure that doesn't happen. As noted, a greater air volume might solve the problem in the direct sun-in-the windshield situation.

 

I use Freeze 12. It is a blend of 134a and other gasses. It is colder than 134a. And yes it has high explosive butane.

 

...which is why 134 blows %^#@ warmer in an R12 car

 

I've used propane based refrigerants for well over 15 years with fine results. I can see no drawback other than it is flammable. But you only use 40% as much in your system. Plus, it mixes with R12 and is fully compatible with R12 lubricant. I used it for over 15 years in an old MB and for 11 years in my track Porsche. I am currently using it in my 328 - well, it is mixed with whatever R12 was left in the system when I charged it.

The change in enthalpy (hfg) as the refrigerant changes phase about twice what it is for R12. It is relatively inexpensive.

 

How do we get it and how do we do it? This is interesting

 

It's been around a while for use in refrigerators. I don't think it's been approved for airconditioner use in the US due to its flammability. THe fact that cars safely carry 15+ gallons of extremely flammable gasoline doesn't seem to have influenced anyone that it might be OK so far...

 

I need one, or at least a seal kit...mine won't hold a charge.

 

I just found out last weekend that my seal in the compressor is shot also,so were looking into a replacement or something,I found in other sites that there is a replacement (york) at Napa autoparts p/n #258108 but been told to just pay the core of $15 to keep the oem and any parts that may be needed,such as the clutch,the part that I've found napa told me $184.39,but that part is painted black,but who's going to see it as long as it keeps you cold,right?

 

Here is where I have always purchased it. Think our systems hold a little over 2 pounds of R12. Given this you only would have less than a pound in it. Being distributed throughout the system as it is, I'll take my chances regarding its flammability. If the accident is so severe that the evaporator in your dash is broken, you're in a world of hurt anyway. Last time I purchased it, a case (12 six oz cans) cost 107 bucks. Shipping, I think, was 25 due to flammability. That was at least 5 years ago.

I have read that the molecule is larger than R12's is. Hence, the gradual leakage is less. The refrigerant has mercaptan in it so it smells like natural gas or propane.
http://www.foxtoolsupply.com/

 

It is understandable why people in the AC business don't like the stuff. It works better and is easy to get. It hurts your business. I believe in what Benjamin Franklin said. A recharge with this product costs about 20 dollars.

Stuff works so well that I have recharged my home AC units with a similar product that is an alternative to R22. My electric bills have dropped in the 3 years I have been using it. Bills are lower by about 10-12% best I can tell.

 

Reading the data on the "SNAP" site, it appears that the issue is that insufficient data has so far been received to certify the hydrocarbon-based regrigerants as a legal replacement due to flammability. Also, as mentioned it is clearly illegal for an ac service provider to install it or vent it. Therefore any ac business would be foolish to ever fool with it until (or if) it is ever approved.

None of this, of course, really affects a private individual from doing it since no one is going to be checking. I personally wouldn't hesitate to give it a try. The product has a odor added that is distinctive to help identify any system leaks, just as natural gas does in your house. At worst, if it doesn't work, you open a fitting and release it all and have the ac serviced as usual. Yes, releasing it is illegal, but so was installing it. Interestingly, releasing a hydrocarbon gas into the air is illegal IF IT IS USED AS A REFRIGERANT. It is NOT illegal to release it otherwise...go figure.

 

Yup, the logic of government regulations always left me in a state of total awe. How can they be so smart and me so stupid as to not comprehend their logic. The odor is mercaptan, same as what is put in natural gas (methane) and propane for gas grills and blowtorches.