Memes

ChrisJ · September 2015

Hatterasguy said:

ChrisJ said:

I remember when R134A first came out for cars everyone said how bad it was, and it was warmer than R12. I converted an R12 system that used a fixed orifice and cycled the compressor to R134A and swapped the low side switch to a lower pressure one which resulted in 36F vent temperatures.

I never had any complaints about R134A when it was used properly.
Another situation with many variables.

On vehicles with marginal condensers, the change to 134 would most certainly result in degraded performance. On those with decently sized condensers, it certainly wasn't an issue.

I've had both good and bad results with it............strictly vehicle dependent.

But again, this is only on converting systems designed for another gas.

The gas it self, isn't bad.

Matt_67 · September 2015

The gas may not be bad but the POE oil that all of the new refrigerants use is a pain. We have replaced a ton of cap tubes on small coolers that have had their condensers neglected. Mineral oil R12 systems were much more forgiving.

njtommy · September 2015

I hate doing Cap tubes!

ChrisJ · September 2015

Ah,
Luckily methyl formate systems use mineral oil and have a skimmer setup in the evaporator to return oil back to the compressor. Methyl formate isn't miscible with mineral oil so it won't flow with it naturally.

Dave0176 · September 2015

Hatterasguy said:

ChrisJ said:

I remember when R134A first came out for cars everyone said how bad it was, and it was warmer than R12. I converted an R12 system that used a fixed orifice and cycled the compressor to R134A and swapped the low side switch to a lower pressure one which resulted in 36F vent temperatures.

I never had any complaints about R134A when it was used properly.
Another situation with many variables.

On vehicles with marginal condensers, the change to 134 would most certainly result in degraded performance. On those with decently sized condensers, it certainly wasn't an issue.

I've had both good and bad results with it............strictly vehicle dependent.

Once the parallel flow condenser came out 134a performance got much better. I tell people all the time when they convert to 134a from 12, the body styles were mostly carry overs during the switch, don't just change the refrigerant and expect it to be the same. I tell them to change the accumulater the orfice tube and the condenser to a later model. Just my opinion but 134 seems to like the parallel flow condensers more then the serpentine ones.

ChrisJ · September 2015

Dave0176 said:

Hatterasguy said:

ChrisJ said:

I remember when R134A first came out for cars everyone said how bad it was, and it was warmer than R12. I converted an R12 system that used a fixed orifice and cycled the compressor to R134A and swapped the low side switch to a lower pressure one which resulted in 36F vent temperatures.

I never had any complaints about R134A when it was used properly.
Another situation with many variables.

On vehicles with marginal condensers, the change to 134 would most certainly result in degraded performance. On those with decently sized condensers, it certainly wasn't an issue.

I've had both good and bad results with it............strictly vehicle dependent.
Once the parallel flow condenser came out 134a performance got much better. I tell people all the time when they convert to 134a from 12, the body styles were mostly carry overs during the switch, don't just change the refrigerant and expect it to be the same. I tell them to change the accumulater the orfice tube and the condenser to a later model. Just my opinion but 134 seems to like the parallel flow condensers more then the serpentine ones.

I also switch to barrier type hoses, otherwise you're going to find it keeps losing refrigerant. On the conversion I did I also did a new compressor and new condenser as well.

New condenser was needed as I stripped the threads off of it trying to remove it after a minor accident.

ChrisJ · September 2015

How is R134a "less capable"?

ChrisJ · September 2015

Hatterasguy said:
The capability of R-134 to transfer BTU's is reduced as compared to R-12.

You may not notice the difference if the condenser is of sufficient size. But, get the vehicle in 95F ambients and the R-134 cannot keep up.

Never switch from R-12.

This is the R-12 system I converted to R-134A the proper way.
Temperature shown was sitting in a parking lot with ambient in the 90s. Fan on high and recirculate on.

Personally, I think 36F when it's in the 90s out and the vehicle is parked is perfectly acceptable.

I cannot accept a comment that says a refrigerant is "less capable" just based on it's performance in certain systems that were not designed for it. Try running R-12 in a system designed for R-134A and let us know how it works.

Anyway, where are the memes?

ChrisJ · September 2015

Hatterasguy said:
Cannot argue with success.

I haven't been so fortunate with R-134. You achieved a DT of 60F with it, which is fantastic. The SD achieves only 30F at the moment.

Like I said, I was running a pressure switch that allowed it to pull the evaporator down lower than originally which allowed lower temperatures. I will admit, I think I had a slight overcharge as I had frost going right to the back of the compressor but it never complained and my high side pressure was acceptable so I left it alone. I also had a fan designed for the towing package as well as a "severe duty" fan clutch which helped a lot and the condenser was fairly large. But either way, it was an R-12 system converted to R-134A.

Apparently methyl formate can move more btu's than almost any other refrigerant, but you won't find good performance running it at 20 PSI as it's boiling point is 89F at atmosphere. No idea what it is at 20 PSIG but I'd guess over 100F.

Another example of a fantastic refrigerant that will perform awful if used in a system not designed for it. To use methyl formate in an air conditioner you'd want around 20 to 22" HG vacuum on the low side. This would give 30-40F liquid temps.

njtommy · September 2015

I wander why they never used R134 for comfort cooling?
We see it in screw chillers, but why not a split system?

ChrisJ · September 2015

Not sure. Why was r12 used in cars but r22 in homes?

ttekushan_3 · September 2015

All I notice are radiators (and vintage appliances/electronics). Can get me in trouble when reposting images.

Dave0176 · September 2015

ChrisJ said:
Not sure. Why was r12 used in cars but r22 in homes?

More then likely had a bit to do with the pressures 22 runs at, you'd need a really large condenser to acheive the same subcool as 12.

Dave0176 · September 2015

ChrisJ said:

Hatterasguy said:
The capability of R-134 to transfer BTU's is reduced as compared to R-12.

You may not notice the difference if the condenser is of sufficient size. But, get the vehicle in 95F ambients and the R-134 cannot keep up.

Never switch from R-12.
This is the R-12 system I converted to R-134A the proper way.
Temperature shown was sitting in a parking lot with ambient in the 90s. Fan on high and recirculate on.

Personally, I think 36F when it's in the 90s out and the vehicle is parked is perfectly acceptable.

I cannot accept a comment that says a refrigerant is "less capable" just based on it's performance in certain systems that were not designed for it. Try running R-12 in a system designed for R-134A and let us know how it works.

Anyway, where are the memes?

Chris how does that import R4 compressor run, I've heard lots of complaints about the import compressors.

I didn't want a brand new or an import this year so I just pulled my compressor appart this summer and resealed it. I got a 99 Tahoe with the HT6 belly leaker. It's working beautiful now. On the highway I'm getting 34-38 degrees, I probably need a new fan clutch but thats for another time. This is a dual air with the rear evaporator.

ChrisJ · September 2015

Dave0176 said:

ChrisJ said:

Hatterasguy said:
The capability of R-134 to transfer BTU's is reduced as compared to R-12.

You may not notice the difference if the condenser is of sufficient size. But, get the vehicle in 95F ambients and the R-134 cannot keep up.

Never switch from R-12.
This is the R-12 system I converted to R-134A the proper way.
Temperature shown was sitting in a parking lot with ambient in the 90s. Fan on high and recirculate on.

Personally, I think 36F when it's in the 90s out and the vehicle is parked is perfectly acceptable.

I cannot accept a comment that says a refrigerant is "less capable" just based on it's performance in certain systems that were not designed for it. Try running R-12 in a system designed for R-134A and let us know how it works.

Anyway, where are the memes?

Chris how does that import R4 compressor run, I've heard lots of complaints about the import compressors.

I didn't want a brand new or an import this year so I just pulled my compressor appart this summer and resealed it. I got a 99 Tahoe with the HT6 belly leaker. It's working beautiful now. On the highway I'm getting 34-38 degrees, I probably need a new fan clutch but thats for another time. This is a dual air with the rear evaporator.

I traded the truck in back in 2009, but the time I was using it the Napa R4 worked great. It was a little louder than a new OEM compressor but not by much. Overall I felt it was a good pump.