Air Conditioner Performance Test (as stated in service manual)

[superdesi]

I'm trying to understand this performance test and can't seem to get it.

First of all I don't have access to a psychrometer & that chart is extremely confusing. I'm assuming that intake pressure means low side & and delivery pressure means high side.

Can someone tell me what the low side & high side pressures should be at 85*F and 90*F (ambient temp) on a properly charged system. Does a static pressure reading even matter?.....or should the a/c be on and the idle speed at 1500 RPMs.

BTW, do our cars take 24 ounces of freon?

[Blkblurr]

I'm trying to understand this performance test and can't seem to get it.

First of all I don't have access to a psychrometer & that chart is extremely confusing. I'm assuming that intake pressure means low side & and delivery pressure means high side.

Can someone tell me what the low side & high side pressures should be at 85*F and 90*F (ambient temp) on a properly charged system. Does a static pressure reading even matter?.....or should the a/c be on and the idle speed at 1500 RPMs.

BTW, do our cars take 24 ounces of freon?

They take 24 ounces of R134A if the system has been evacuated. they take about 28 ounces of R12. I never bother with the performance test because it really doesn't matter to me. If you have a sealed system and fully charged after pulling a vacuum on it and assuming your compressor is working, you will get the best performance you can get. Whether it's R12 or R134A you will not get any better performance knowing what the low side and high side pressure is. Just pay attention to the 60 psi limit on the low side. Now if your trying to determine if your compressor is working to it's design parameters you might care about the tables. R134A will not cool as good as R12 because our systems were not designed for it. They will however work good enough.

[Oldblueaccord]

I'm trying to understand this performance test and can't seem to get it.

First of all I don't have access to a psychrometer & that chart is extremely confusing. I'm assuming that intake pressure means low side & and delivery pressure means high side.

Can someone tell me what the low side & high side pressures should be at 85*F and 90*F (ambient temp) on a properly charged system. Does a static pressure reading even matter?.....or should the a/c be on and the idle speed at 1500 RPMs.

BTW, do our cars take 24 ounces of freon?

134a I'm thinking 40 psi low 225 high these are ballpark numbers after the AC been run compressor cycling etc. a good 15 minutes. Do a google search. I think its www.aircondioning.com or something close to that they have charts,general info, and a helpful forum over there.

Since you asked a few good questions about AC maybe you should pickup a set of real guages and study up on it. Its a good career to get into esp in hot climates. there quite a bit of schooling to get licesense now days so I never really was to interested any more then to fix my own system.

wp

[Oldblueaccord]

i should be out changing the collecter gaskets on my headers but since its 90 degrees out i di a search for you :sad2:


http://www.acsource.net/acforum/ forums

http://www.aircondition.com/dsmobileac/blend.html Freon blends

http://aircondition.com/knowledge_base/Home.html says it al in the link :deal:

http://www.epa.gov/ozone/title6/609/index.html there the bosses :dunno:


lets us know what you learn i could always know a little more.


wp

[superdesi]

Thanks for the info. I already have a set of Yellowjacket gauges, a new vacuum pump, and a flushing agent. I needed an opinion on the amount of factory refrigerant because I have heard everything from 24 to 26 to 28 to 32 ounces.

[Oldblueaccord]

Thanks for the info. I already have a set of Yellowjacket gauges, a new vacuum pump, and a flushing agent. I needed an opinion on the amount of factory refrigerant because I have heard everything from 24 to 26 to 28 to 32 ounces.


its listed as 25 ozs on one of those sites.


readin thru the forums they reccomend going by vent temps mostly creeping up to the maxium anmount of freon needed. Any more and you loose eff.= temps go up.

Himm im sure im over then cuz im one of those people that think more is better :uh:

81 degress and 71% humidty yeah me.


wp

[Vinny]

http://3geez.com/showthread.php?t=35679

[Blkblurr]

Maximum capacity for our system using R12 is 28 to 32 ounces according to the manual. Use 80% fill for R134A due to higher pressures. At 24 ounces of charge of R134A I had no bubbles in the sight glass on the receiver jar and an operating pressure of 55 psi low side. I charged it on a day that was around 80 degrees in my garage with a dew point of 65. My vent temp was 41 degrees at full charge and engine at Idle. My system was evacuated before filling. Hopefully this will help benchmark what it takes.

[Oldblueaccord]

Maximum capacity for our system using R12 is 28 to 32 ounces according to the manual. Use 80% fill for R134A due to higher pressures. At 24 ounces of charge of R134A I had no bubbles in the sight glass on the receiver jar and an operating pressure of 55 psi low side. I charged it on a day that was around 80 degrees in my garage with a dew point of 65. My vent temp was 41 degrees at full charge and engine at Idle. My system was evacuated before filling. Hopefully this will help benchmark what it takes.

thats sounds about right pretty good vent temp. Id imagine thats with an original condensor? Is guess your high side may be 260psi but thats a guess.



wp

[Blkblurr]

during this repair I didn't pay enough attention the the high side pressure but I know it was around 245 to 260 range. Yes I do have the original condensor.