The other night as I was working on some things in my 1971 cutlass, while working I turned on my car and the ac and the vent temp at idle was around 60 degrees after a while. A day later at the height of the sun and heat, like 94 degrees, I turned on the car and AC as I let the car idle(about 9+ minutes)the vent temp seemed to get no lower than 80 degrees. My question is if I had a parallel flow condenser and it had an electric fan, would my AC go to 60 degrees on the hot day? Does the condenser have that much effect? Would I see lower vent temps than 60 degrees?
thanks for your help
FYI, 1971 Cutlass 350, flex fan and clutch, r134, A6 compressor, new cycling POA valve, new expansion valve, no, I didn't get any pressure gauge readings(which means it's hard to help, I know, but my question is more general in intent)

 

With the AC running touch the low pressure line. Does it feel cold?

 

If the low pressure side is the side with the POA valve and the side that's normally cold then, Yes it feels cold, but there are times when it's really cold and other times it's cold.

 

You do realize that the car cooled just fine from the factory without any of that stuff, right? I've done several R134 conversions and didn't change condenser or evaporator. Check the pressure. Sounds like you're low on freon.

 

Mr. Joe, do you know what temp from the vents, generally, you get on your conversions? I ask because if I can get 60 degrees or less at my vents regardless of the ambient temp, extreme heat excluded, I'd be ok I think. If you're getting those terms or better without changing the condenser and adding a fan, I'm cool with that.

 

I have not used a thermometer in the vents, but the cars get plenty cold here in the 95 degree, 90% humidity DC area summers.

 

I don't know what you can get out of your R134 conversion, but I recently rebuilt my R12 system to include rebuilding the A6 compressor, replaced all hoses and the dryer. I now have 36* temp out of my vents and it sure feels good in the Arizona sun shine.
The compressor really isn't difficult to reseal. With what ever freon system you go with it should cool lower than 60* vent temp.
Are you sure that your compressor is engaging?

 

Wow 36*!!!! I wish. I converted to r134, all same hoses except the house connected to the expansion valve. Finding And paying for r12 was not going to work for me. Id like to get the most out of the system I have right now. If I could get vent temps around 40 degrees no matter the ambient temp I'd like to know how with my set up or do I need the parallel flow condenser and fan?

 

From all I have read, the R134A conversions do not cool as well at idle as R12. What's your vent temp once the vehicle is moving and the engine is around 2000 RPM or so?

 

I will have to wait a day or so to see the temps while moving, my dashboard is off (I got another project on the Cutlass). Once I put it all back together I'll check the vent temp then, plus I need to get the high and low side pressure readings. I'd like to see if my AC can work good like Joe's without changing my condenser

 

Your not going to cool anything at 60*F air temp. Seems you have a low charge. My 77 had 35*F air coming out. ALL original including fresh R-12 I just put in.

 

Mike, I understand using r12 getting those temps especially using an ac designed for r12. But I have some r12 parts, except for what I mentioned before, but am using r134 refrigerant trying to get those same results. Also I had to much freon because it wouldn't cool any, maybe I took too much out. I'm hoping to let an expert put the gauges on it and hopefully find the sweet spot. If not I need to try changing my condenser to a parallel flow for r134

 

Without changing any thing and putting in 134a the condensing pressure is going to be high. That equates to high temp. The system seems like it short on Refrigerant. Put in a little at a time untill the suction line starts to feel cold.Should be around 40*F

 

ok so today i took my car to a mechanic and he put the car on this ac machine. According to the machine i had too much refrigerant we evacuated some to get the low side down a little bit. it seemed to work, but here's the strange thing, i think the temp gauge I was using didn't work, or it adjusts too slow because the mechanic had a laser temp gun and it was reading in the 30's and 40's. My needle-mechanical gauge was reading around 80 degrees. ill do more checking in the morning

 

Okay so I had 2 temp gauges on my AC vents today I had the long needle like turkey tester temperature gauge and I had the the laser gun temperature thing. The gun was reading 40s and 30s in my vents and the turkey tester gauge was no lower than 60 degrees both at idle which gauge is more accurate?

 

Why don't you use each one to measure the temperature of an ice cube and boiling water to check the calibration of each?

 

The man with one watch always knows what time it is. The man with two watches is never quite sure.

One gauge is reading in the 30s and the other near 60? That's far enough apart that you should easily be able to determine which is closer to the truth by just sticking your hand in front of the vent. Mid-30s is typical refrigerator temperature.

 

And the broken watch is right twice a day...

 

lol, philosophy is a bonus!!
Last night I calibrated my mechanical thermometer and compared it with the readings from the laser thermometer i borrowed from oriellys, and the both were consistently around 52-56*. I suppose that's the best I can get, and I guess the mechanics gun was wrong. I wonder if I put a fan on the condenser would it help me get consistent vent readings in the 30's using my r134 setup. I've read the r134 don't cool as well using the r12 condenser because it doesn't cool down as well. For now I'm keeping the factory fan, shroud, and condenser, but I'm thinking of adding an electric fan for the condenser. What do you think?

 

This may be a another case of my ignorance showing, but I can't remember ever seeing such a combination. Please educate me on why and how such a combination came to be. Thanks.

 

I believe that's my mistake I don't have a flex fan I have the factory fan blades with the clutch that came with it. Of course I've replaced the clutch but my fan blades do not Flex

 

I doubt if you'll ever see vent temps better than what you're seeing with R134. Be happy, or go back to R12.
just my .02

 

This goes this goes back to my original post. with an updated condenser and fan I was hoping to get colder temperatures than that. Then I was told that I can get that with my current setup it just needs to be adjusted out right. I cannot go back to R12, from what I read it's too expensive for me so either I make what I have work better or I switch over to a new condenser, the parallel flow kind that works better for R134. It's possible I'll get down the road and my current vent temps might work just fine. But I'm getting 40 degrees in my daily driver and I'm not sure that 15 degrees higher is going to feel as good, the same, or better. I'm just looking for solutions as to how to get the best cooling that I can. I like to be cold when I drive. If I wanted to just be happy I would have never made the original post. If my system is working as efficient as it can, then so be it, but until I know that for sure I'm going to keep asking questions because all of this I'm learning as I go.

 

You can't afford R12, but you will spend the same amount of money or possibly more for an electric fan and a new condenser?

 

Yes sir it will cost more overall. When I started rebuilding I didn't know what I was doing so I listened to others and so converting over to 134 has already been done so in order to go back to R12 that's an extra expense plus the refrigerant is more expensive than the R134. The fan and the condenser would probably run no more than $70, it's a universal condenser $52 ebay. I think I'd have to change my compressor in order to return to R12. However R12 is not as expensive as I thought. I just googled it, it's still more expensive than r134 though. If all I have to do it's evacuate my system and put R12 in them I can consider that but I think it's more to that like changing the POA valve and other stuff. For now I've decided to just get the fan it's under$20 and see how this current setup feels on the road. It may be exactly what I want. I haven't tried it out on a long trek yet

 

Ok, so this past weekend we drove the car and it was hot inside and outside the car. It was like 99* outside and The duct Temps didn't get no less than about 58 degrees inside, so I added an electronic fan to push more air through the condenser, and it was getting duct temps around 48* . To be fair, it was like 90* outside so I wasn't as hot as was the other day. Seems like the electronic fan helped. Now my daily driver is getting sub 40*temps at the vents, I'd sure like to get there one day. I wonder again, would changing to a newer aluminium parallel flow condenser along with the fan i added drop me 8* at the vent? And which direction do I turn the screw on my poa bypass(clockwise or counterclockwise). I feel the compressor cycling on and off too frequently.