Zoomspeed

is there anyway to get colder a/c?

when its ~95 degrees here, with my a/c on full blast its still like an oven in my car. I just converted my car to 134a. I don't rember how cold it was with the r12.

Maxboostrx7

Just charge new air condition... still oven..
it got hotter after i put koyo radiator..

noon

Mine blows ice cold

Blade7

me kool

Zoomspeed

oh let me clarify something, the a/c does blow cool, just not cold enough to cool down the cabin, unless I'm driving aroudn with the a/c on full for at least 15 minutes

JConn2299

I don't know how you did the conversion, but 134a as a refrigerant isn't quite as efficient as R-12. For the system to be as effective as R-12 it requires a bigger
(and here I forget which part it is) condenser / evaporator. I'd suggest seeing a good A/C specialist to fix the problem.
We had this thread a couple of weeks ago and somebody mentioned which part it is you need to upgrade.

Zoomspeed

I relaize that 134a isn't as good as R12, but is shoudl still be able to keep my cabin cool.

Isn't the condenser/evperator just a heat transfer device. So bigger condenser/evapreator would rasie the efficency of any a/c system regardless of r12 or 134a. Somewhat liek a larger radiator for the cooling system. But then again, I'm no a/c expert.

An a/c shop will rip you off on everything, especailly a 134a conversion. Shops arond here wanted ~$400 to do a conversion which anyone can do themselves for $30.

JConn2299

The 134a and R12 are different systems, it's not just a matter of a different kind of refrigerant. Because the 134a doesn't absorb heat as efficiently as the old R12, a compensation has to be made. Why do you think your car isn't cooling as good as it used to?

Here's some info I picked up on one site on 134a conversions:

"If an R-12 system is performing marginally, retrofitting alone will not make it better. In fact, since R-12 systems were not designed for use with R-134a, owners should be prepared for a slight reduction in a/c performance. In most parts of the country, this reduction will not be significant, and vehicle owners may not notice any difference in performance.

In warmer climates, however, where the a/c system is running at full blast many months during the year, performing a simple, least-cost retrofit may not produce satisfactory performance. In that case, a technician should be able to recommend what additional steps are most appropriate -- possibly installing a larger condenser, or adding a fan or high-pressure cut-off switch. Although these steps make the retrofit more expensive, at least the car owner has a choice of options."

rajeevx7

iTrader: (11)

i am the single owner of a 93, and ten years later i have the same problem with my ac. i live in florida, the cooling is only have as good as any domestic car ive been in. has anybody fitted a larger compressor to thier little bad *** rotary rocket fd? please pm me

Zoomspeed

I understand that it won't be as cool, but it was only 95 degrees and it wasn't enoguh to cool down the cabin. I'm sure the reduction isn't so significant that it cant cool my small cabin in 95 degree weather. IS it?

duboisr

tint your windows to help keep the heat out . there is another gas better than r135 just search .Auto Haus, in Murfreesboro Tn. sells it as well as some other shops in town .Garfinkle has it and it is to cold .

Blackbeast

What exactly is changed to convert from R12 to R134A? reason I asked was my car was recently converted and a/c deplored itself, now I am left with no a/c at all.

Timmy

JM1FD

iTrader: (1)

If the system has barely enough capacity when working properly (which these cars are guilty of), then you'll notice it. The converstion done on my 1990 Dodge POS truck certainly decreased performance with ambients above 85 degrees, as did the conversion on my ex's '88 GXL. Then again, I live in East Texas, so the systems has to fight high heat, as well as high humidity. My 1998 SC 400 uses R-134a, and its the best car A/C I've ever had...but it was designed from the ground up to use R-134a.

Its only 95 degrees outside, but what's the temperature in the cabin? How much heat is still in the dash/chassis/seats? Are you rolling down the highway, or putting around town? These are all factors which change the cooldown time....

JM1FD

iTrader: (1)

Most of the time people just change out the service valves, throw in some double ended oil, and fill it....

In a perfect world, you would change out all of the non-compatible seals & hoses, compressor, condenser, evaporator, expansion valve, purge the system of any remaining mineral oil, then charge with R-134a.

To do it *right*, you should, at the very least, find & fix the leak, purge the oil, replace the dryer, add new oil, pull a deep vacuum, and recharge.

JConn2299

Yes it is. That's what the passage I quoted is saying. Someone more knowledgeable than myself says the problem is with the design of the A/C system in the FD.
It's a sportscar...it's small...and there is limited airflow because of the intercooler, the air needed for the engine, the aerodynamic design on the front of the car and the premium put on reducing weight. All this adds up to an A/C design that already operates on the margin, and when you replace R12 with the less efficient 134a, you can wind up with a problem like you're having.

I own a '95 which came with the 134a system. It seems to work fine for me even on 100 degree days, although I don't think the system has the 'ice box' capacity I've seen on some American cars. My guess is they enlarged the condenser and made some other changes when they went to 134a in '95.

To get good cooling I think you're going to have to get a better condenser or set up a fan to run air over the one you have (although that sounds like an awkward solution and might present other problems.)

You can buy an A/C temp guage for just a couple of bucks at any auto supply store. If the air coming out of the vents isn't in the mid to low 40s temp range, then your system isn't operating as good as it should.
Of course, your other option is to go back to the old R12. It isn't cheap, but it's still around, and it may end up being cheaper than doing what is required to make your 134a conversion as efficient as required.

djantlive

It takes a good 10 min to cool the car if it's sitting in the sun under 95 degrees. Tinting the window is a must if you live in hot weather. Leaving the window open a little while parked helps too.

JM1FD

iTrader: (1)

The only change that I'm aware of (according to the mailing list), is that they increased the fin density on the condenser, no size or number of row changes, and I'll bet they changed the expansion valve to optimize it for the new refrigerant as well....

jf4828

Last time I posed that question to an AC guy he told me it's just the expansion block. I worked in a shop a few years back and to the best of my recollection it is a very simple conversion, usually costing less then a recharge for r12. The expansion block is the only thing that has to change because the properties of the refrigerent are different and have to go through a diffrent size valve to cool. It works just like a C02 cartridge. Pressure X Volume=n X R X Temerature. Therfore if pressure decreases so does temp. There are no reasons to change anything else.....