A/C Recharge Clarification Needed

[Strum]

I searched the forum and couldn't really find a clear answer to what I am looking for.

I recharged my A/C with Enviro-Safe 12A and I am not getting the air as cold as it should be.

The can says fill to 60 lbs, but people here and elsewhere advise 40 lbs. Any thoughts on where it should be?

I thought (apparently incorrectly) that you filled until it stopped accepting any more 12A, but obviously that is not the case. I also see mention of can size as if that is important to filling. Other than more or less in the canister, is there any other significance?

One last thing, I was searching google and one site I came across noted that the low side should be 60 and the high side should be 200. Since the advice wasn't make and model specific, I wouldn't follow the advice. However, what are they referring to when they note high and low side?

I may be beating a dead horse with these questions, but I can't seem to locate answers I am comfortable with.

[Stillrunning]

Despite what I told you, you don't have a clue what you're doing. I would buy a Haynes Heating/Cooling manual (non-vehicle specific) and learn some basic A/C fundamentals, find out how much R12 the system holds and get yourself a set of gauges. Then READ the 12a can specs as to how much 12a equals R12. I have converted to Enviro-Safe 12a Industrial and am getting betting cooling than I ever got from R12.

[flyeri]

Unless you know what you are doing you can really mess up your a/c unit. Unless you are adding a bit for the little leak that many systems have over a year you need the correct tools and knowledge. Stillrunning is giving good advice.

[Strum]

Originally Posted by Stillrunning

Despite what I told you, you don't have a clue what you're doing. I would buy a Haynes Heating/Cooling manual (non-vehicle specific) and learn some basic A/C fundamentals, find out how much R12 the system holds and get yourself a set of gauges. Then READ the 12a can specs as to how much 12a equals R12. I have converted to Enviro-Safe 12a Industrial and am getting betting cooling than I ever got from R12.

I got what you told me, but I am not getting the additional information in my search.

I'll get the Haynes book you are referring to. As for my system, I don't think I have to worry about damage, as it is down at 30-35 range.

[Stillrunning]

Originally Posted by Strum

I don't think I have to worry about damage, as it is down at 30-35 range.

Static or with A/C on and at what ambient temp? This was your first mistake when you originally filled the system, you went by static pressure, which has little to do with proper fill level.

[Strum]

Originally Posted by Stillrunning

Static or with A/C on and at what ambient temp? This was your first mistake when you originally filled the system, you went by static pressure, which has little to do with proper fill level.

Did a lot of reading last night from various reliable sites to get a little more understanding of the process. Certainly don't have it all, but the idea of importance of the various steps and the "need to know" things are becoming clearer.

One gets the idea it's just fill and go based on walking into a store seeing cans of 134A with a gage and hose on the top of the can.

[Strum]

Originally Posted by Stillrunning

Static or with A/C on and at what ambient temp? This was your first mistake when you originally filled the system, you went by static pressure, which has little to do with proper fill level.

Strictly low side readings.

ambient temp: around 78 w/humidity at 65%

Static pressure: around 85

Pressure w/air on, high speed, recycle, windows open = 28 to 30 before climbing. RPM at 1200

Compressor kicked in around 45

Temp of air from vent at 1200 RPM 45-50 (car in Park)

Temp during driving: 40 - 42

I'm going to see if I can find some gauges to borrow to test high and low.

As for performance, marked improvement, but I want to see how it operates over the next few days. We've been having relatively mild weather (no 90 degree days), but we have an 85 w/high humidity expected Tuesday.

I was curious about the temp of the tubes going in and out of the receiver/drier, should they be hot or cold?

[Stillrunning]

Originally Posted by Strum

Temp of air from vent at 1200 RPM 45-50 (car in Park)
Temp during driving: 40 - 42

Nothing wrong with that. You'll have to wait til you get ambient temps up in the high 80s and 90s to see if the system maintains those outlet temps. The best place to measure outlet vent temp is just after the evaporator, but that's not possible. Seems air temp rises about 5* from just after evap to upper vent. You don't want the evaporator to freeze up which would be 32F. You'd know when you got little to no air flow. Don't forget you're dealing with an old system.

I was curious about the temp of the tubes going in and out of the receiver/drier, should they be hot or cold?

Don't worry about the evap tubes temp.

[Strum]

Originally Posted by Stillrunning

Nothing wrong with that. You'll have to wait til you get ambient temps up in the high 80s and 90s to see if the system maintains those outlet temps.

It was somewhere around 83 - 85 today with humidity around 60%. I got in the car after work and it was 110 with the windows cracked open slightly. I took the thermometer with me and monitored it for the 20 minute ride home.

It hit 50 degrees pretty quick and then about 5 min into the ride it hit 40 and held steady with the fan on lowest setting.

Don't worry about the evap tubes temp.

The reason for the question was in my reading over the weekend I recall one site noting that if both tubes were the same temp, the system was full. It went on to say if one was colder then the other, the system was either over charged or under charged, depending on which one was colder. They used the word "colder" but didn't note what temp they should be. Since you say not to be concerned, then I won't worry about that.

Most sites note the sight glass as the way of telling. Based on that, mine appears to be white when running (foam?). It is not bubbles as I saw on one site, but more of a fast rushing foam. It went on to say that if there was a foam like appearance, the system is under charged.

Is the sight glass the best way to determine if you have the right charge? Is there a better way to do it? My concern would be an over charge.

Hey, thanks for putting up with some of the stupid questions earlier, but I was at a loss and couldn't find info.

[Stillrunning]

Originally Posted by Strum

Is the sight glass the best way to determine if you have the right charge?

Sight glass was for R12. 134a in R12 system produces bubbles in sight glass. I'm not sure about 12a as I haven't taken notice of the sight glass as the gauges and outlet vent temp are the best way to determine if system is correctly filled. I wouldn't pay attention to sight glass. Low side high and high side high can show over charge. I would still find out how much 12a = R12 then refer to Toyota specs and see if what you put in was about right.

[djb2]

I'm pretty sure I know the answer to this but...

Was a vacuum pulled on this system before the refrigerant was added?

If not, that would explain the high pressures and uncertainty about the fill level.

[Strum]

Originally Posted by Stillrunning

Sight glass was for R12. 134a in R12 system produces bubbles in sight glass. I'm not sure about 12a as I haven't taken notice of the sight glass as the gauges and outlet vent temp are the best way to determine if system is correctly filled. I wouldn't pay attention to sight glass.

I keep forgetting that I can't rely on R12 info for information pertaining to pressure, visual, amounts...

Low side high and high side high can show over charge. I would still find out how much 12a = R12 then refer to Toyota specs and see if what you put in was about right.

"6 oz. of Enviro-Safe is equivalent to 18 oz. of R-12 or 16 oz. of R-134a."

[Stillrunning]

Originally Posted by Strum

"6 oz. of Enviro-Safe is equivalent to 18 oz. of R-12 or 16 oz. of R-134a."

My 134a Camry holds about 30oz so that would mean I'd add almost 12oz of 12a (11.25oz) or about 2 cans. If the R12 system was designed for approximately the same volume then you'd add 10oz of 12a. How many cans did you add? You still need to know how much R12 the factory specs. When converting from R12 to 134a you add 80% of R12 volume, but I don't know if my 134a system reflects 80% of what an earlier R12 system held.

Originally Posted by djb2

Was a vacuum pulled on this system before the refrigerant was added?

I believe djb2 thinks there might be water in the system - it's possible. Did you replace the receiver/dryer? There might also be some R12 mixed in the system if you did not pull a vacuum and replace the receiver/dryer.

[Strum]

Originally Posted by Stillrunning

My 134a Camry holds about 30oz so that would mean I'd add almost 12oz of 12a (11.25oz) or about 2 cans. If the R12 system was designed for approximately the same volume then you'd add 10oz of 12a. How many cans did you add? You still need to know how much R12 the factory specs. When converting from R12 to 134a you add 80% of R12 volume, but I don't know if my 134a system reflects 80% of what an earlier R12 system held.

I haven't confirmed, but all Camry's since at least through the 90's seem to have a capacity of 28oz to 32oz. I still would like to get solid confirmation on that. What I have in there right now of the ES would be equal to 30 to 32 oz. I have to check under the hood to see if I can find anything, although most of the info under the hood has slowly faded away.

I believe djb2 thinks there might be water in the system - it's possible. Did you replace the receiver/dryer? There might also be some R12 mixed in the system if you did not pull a vacuum and replace the receiver/dryer.

I would like to answer differently, but no evac, no new receiver/dryer.

Prior to adding ES, the static low side reading was 0 (zero).

My concern now would be that despite the system is performing very well, could I slowly be causing damage?

[cj0609]

i just added a can and a half of freeze 12 and my air is ice cold.