AC refrigerant advice

[Chris Cornett]

Hey guys its time for a charge on my Limited. I have heard a lot of bad things about R134a in these cars. I know it is not very effecient. I was thinking of using Freeze 12 or some other substitute that has R12 in it. I am planning on evacuating the system before recharging. Any opinions

 

[T-top87GN]

Nothing has R12 in it, except R12. You can't run a mix of refrigerants. It won't work and may possibly ruin your compressor. You especially can't run the older refrigerants with the newer ones. The newer refrigerants use Polyalkylene glycol (usually called PAG oil) or a Polyolester oil (called ester oil). Older refrigerants usually used some variation of Mineral Oil.

As far as what's better....a properly evacuated and retrofitted system with 134a will work great. Alot of guys are using the Freeze12 with great results as well. If you are really worried about it, you can get your system recharged with R12. It's running about $25.00 a pound right now. At least around here it is. Good luck!

 

[Nick Micale]

Originally posted by Bandit
..........As far as what's better....a properly evacuated and retrofitted system with 134a will work great. Alot of guys are using the Freeze12 with great results as well....
....with R12. It's running about $25.00 a pound right now. .... Good luck!

Really should clarify about 134a "works great" as a general statement. The conversion of older cars, like our GN's, are usually not comfortable in temps like here today - 112 degrees on my patio or yesterdays 119!

The 134a refrigerant is less efficient than R-12 and does NOT cool as well. However, in MI and Ohio and similar areas, it may do the job ok. Make sure you compressor is in good shape as the increased head pressures of 134a will need it to be.

If R-12 is only $25 a pound, use it for sure. Retail locally is $65 a pound.

 

[Ormand]

yeah, what Nick said...

If you can want to spend a lot of money, to replace the condenser with a more efficient condenser, you can get close to the same cooling with R134a that you got with R12. The stock condenser was not optimized for R134a, and, as Nick said, R134a is just not as efficient, but with a matched condenser, it should be Ok, even in the heat of Arizona. If you go for a ride in new car, you will feel pretty cool. Well, maybe not as "kewl" as in a T or a GN, but you know what I mean...

 

[Sal Lubrano]

Where can I find a Piccalo or parallel flow condenser for my Buick?
Sal

 

[turbodave231]

A TR or GN properly retrofitted to R-134A will work well for most climates. Nick, be honest, how well does R-12 work on those 119 degree days? Nothing short of a block of dry ice is going to cool a black car in stop and go traffic in the desert. I know, I've spent alot of time testing AC systems down there at the DPG.

For most of the country R-134A works pretty good. You will end up recharging the system more often because the smaller molecules of R-134A will leak out the plain rubber hoses our Buicks were built with. Cars designed for R-134A have barrier hoses (lined with a plastic sleeve) and double o-rings on all the fittings.

I wouldn't hesitate to use R-134A with PAG oil. You can buy small cans for as cheap as $6.00 a can. Compare that to well over $30 a can for R-12 and R-134a is a deal.

Stay away from the blended refrigerants (R-12 substitutes) they will cause you problems like high head pressures, poor lubricant movement and poor cooling performance. Oh yeah, you can't recycle blends either so no reputable AC tech will want to work on a car that contains a blend.

Just my opinion.

Dave

 

[49-blues]

Nick-what do you mean about the head pressures of 134 "as compared to r-12? all the charts i look at show 12 with a slightly higher pressure as compared to 134.

 

[Nick Micale]

Don't know about the charts, have not seen the ones you refer to. If it is for later model cars that were designed and built with 134a systems, that may be true.

Was mainly speaking about retrofit older cars with smaller condensors and evaporators that used R-12. At idle, most 134a cars cool very poorly. At RPM, the gage pressures exceed most
R-12 cars.

What is not mentioned in any comparison is the cool down time. In our summer temps, and other areas with LOTS of hot sunshine, a vehicle may be 140 degrees or more when parked for a while. It takes a significant amount of time for any car to cool enough to drive, but converted 134a systems hardly can do it before the end of the trip.

Another factor to consider is the engine coolant temps. At 110+, this adds LOTS of heat into the condensor which further reduces the effiency of a 134a converted system and taxes even the R-12 systems.

 

[49-blues]

nick- have you heard of adjusting the low pressure switch cut out to help compensate for the difference in effeciency of the 134? there is supposed to be a slotted screw in between the two prongs of the low pressure switch that will help the temps.

 

[Wicked]

No more talk about 134A not being as efficient as R12. 134A is
more efficient than R12. 134A absorbs heat greater than R12
by a mile. The problem is it does'nt like to release heat ,say through the condensor. Newer cars are built with more efficient
front ends to aid in heat dissipation. I've done many conversions
and most older GMs do not do well. Turbo Regals have too much heat in the front end to be efficient. Its the cars not the 134A.
I run R12 in mine and its a fridge.


Something Evil This Way Comes

 

[Chris Cornett]

Thanks guys R12 here is about $60 a pound. I know it works best. Thanks for the help. BTW, I thought I read somewhere that freeze 12 was like 35% R12?

 

[49-blues]

Wicked-call any manurfacturer of 134a and they will tell you 134a is 10% less effecient than r-12. At work we converted a 1000 ton ac chiller originally r-12 to 134a, after the change in refrigerant the machine now only will do 900 tons of refrigeration.FYI

 

[49-blues]

Its actually our cars and the refrigerant that gives us cooling problems.

 

[gn4u2c]

Hmm.... I have gone to 134a and it as just as cold as ever on 90+ day's I do leave the windows down for the first 30 sec or so when I start out

 

[GNandTTA]

Is there another condensor that can be bought to make a GN retro'd with 134 cool better?

 

[lrover2]

AUTOCOOL 12A . $70 a case! Very cold. No conversions. Mixes with R12 and 134. Ozone safe. NO LICENCE REQUIRED. You can read more here
www.autocool-refrigerants.com

I use it and it works great!

 

[cougarcat]

Just had mine done a few months ago. R-12a or Duracool(whatever you prefer to call it)---took almost 3.5 cans. Complete vacuum down for 15-20 minutes, service with the r-12a, etc. Out the door $78.00. Cools great (even with the front mount IC)---although it only hits 90-98 here in Atl. Nothing gets changed---totally compatible with R-12 systems. This is my first experience with it, and so far I'm completely sold.

Gerry

 

[dwithers]

I just installed replaced the compressor, accumulator and orfice. Flushed (which was very clean), vacuum and charged with R134A. Won't get any cooler than 58 with the windows up, at idle, 95 outside. Gauge readings were right on the money.

Very disappointed.

 

[John84GN]

Freeze 12 !

I did the R-134a conversion in my n/a regal about a year ago, and I did the one in the GN about 6 months ago...Heres the what I did to answer some questions. All the quotes about which one absorbs heat better, and this one's molecular structure is greater...or WHATEVER...this is what I KNOW.

Yesterday it was 92 degrees w/ a 100 degree heat index:
both cars at idle for about 10 minutes:

The Regal got to 64 degrees...

The GN got to 37 degrees...
When I opened the door to the GN...smoke (like when you open a freezer door) came out...

You do the math...I would NEVER use R-134a again...I saved about $300 going w/ Freeze 12, and I would recommend this to anybody...!

my $0.02

 

[John84GN]

forgot to mention that the thermometer that I used was one of those small "meat looking thermometers" about 8" long and the dial is about the size of a quarter...I placed it "in" the actual vent in the middle...