Air Conditioning Questions

[Moby]

My 1992 Accord with 46k original miles and the original A/C system has always had cool A/C on a 100 degree day and cold on a 60 degree day but not ice cold like in GM cars of the 80's that would freeze you out on hot summer days and get cold very fast. Two summers ago, I had the A/C system checked. The technician found no leaks and added two pounds of refrigerant and the A/C was registering at 46 degrees. He added a dye in case a leak developed. The A/C was a little cooler summer and the one after, but not dramatically. I didn't drive the car last summer and today when I turned on the A/C to test it out, it was cool on a 70 degree day but not cold.

Are the A/C units in 1990-1993 Accord's inferior compared to other cars or is it just my unit?Do small cars have weaker air conditioning systems than larger cars? The a/c seems to be the only weak spot on an otherwise beautiful looking and great handling car.

Is it true that all cars leak air conditioning refrigerant? Is age or miles (use) a bigger factor in determining the longevity of an a/c system or is it just luck how long any system will last? I've always liked old (10+ years) cars with very low mileage because of their good value purchase wise and longer potential usability due to little use.

[iamcoons]

To answer your questions...

1) Are the A/C units in 1990-1993 Accord's inferior compared to other cars or is it just my unit?

They're not inferior, they're just old. Mine is good in the summer sitting at a light, it's better when I'm moving cuz the condenser gets more airflow than when the A/C fan kicks on.

2) Do small cars have weaker air conditioning systems than larger cars?

They just have smaller systems. Thus less refrig in the system, thus less cooling capacity.

3) Is it true that all cars leak air conditioning refrigerant?

It's normal for some leak-down from the A/C system, so they need to be charged every 2-3 years.

4) Is age or miles (use) a bigger factor in determining the longevity of an a/c system or is it just luck how long any system will last?

Age usually is. Rubber has a shelf life of 5 years. After that it kinda craps out. Since your A/C has rubber seals in it and it's gettin close to 20 years old, there's a good chance one (or more) of the seals is leaking.

Hope this helps.
The next post is the big explanation of some simple checks you can do.

I apologize in advance for being wordy.

Dave

[iamcoons]

Got a few observations and questions...

I've had a few issues with my A/C that were resolved pretty easily:
Bad O-Ring on my compressor - Leaked Refrig & Dye
Bad Expansion Valve (in the evaporator case) - not opening & closing

So the A/C worked a-ok after that.

Just so ya know: Never undo the fittings for the A/C if you think there's refrigerant in the system. It's under a lot of pressure, it's toxic, and refrig handling needs EPA 609 certification.

1) The A/C in your car should run on R-12 refrig. R-12 (very expensive) gets colder than the new R-134a just because of the thermodynamic properties of the refrigerant and your A/C system.

So have you had it converted to R-134a? There should be a proof of refrig conversion sticker that the mechanic put in the engine compartment.

2) 2lbs of refrig means the system leaked out completely. Spec is 2 - 2.1lbs of R-12 (75-85% of that if it's R-134a b/c R-134a is a larger molecule than R-12, thus different cooling properties). Even when dye is added, it can be tough to trace some leaks. Especially if they're in the evaporator case and they're very slow leaks.

Have you had the evap case apart? it's behind the glove box near the blower motor case. If you get in there you may find dye.

3) You have to have excellent air flow through the condenser (in front of the radiator) and the evaporator (in the dash) or else the cooling won't be any good. Think about how hot your engine would be if your radiator didn't get good air flow. It's the same for the A/C system.

Taking that into consideration... check the condenser for clogs. If so: just rinse it off with a garden hose & sprayer.

4) If you feel like checking the evap case, pull the blower case out (should take about 45-60 min to get it in and out if you don't have to wrestle with it too much) and check for leaves, dirt & debris in the evap core.

Mine had some just cuz I always keep the fresh air (not recirc) comin in the car.

If you don't see clogs in the evap case, it's prolly time to get the system dyed & charged, and that means takin it to somebody who knows how to handle A/C systems & refrig.

Ok? If you've got more questions, put em up, I'll try to answer em.

Dave

[wherm]

your car uses R13 refrigerant, which I feel is better than today's R134, but harmful to the environment which is why it isn't used in new cars. I've always been told that it is better refrigerant. Seems like everything that's bad for the environment is better than what's environmentally friendly now days.

Anyway, you can take your car to a shop and have them use the UV light to look for a leak, which there very could be one, and get it recharged. Not all shops will have R13 though, so make sure you take it somewhere that does.

Your other option would be to convert to R134 which involves a new reciever/dryer and new oil and seals for the a/c system. It also comes with new fittings. It's a retrofit kit, and works pretty well. If you can stay with R13 I recommend doing that. In the long run though, R134 is cheaper/lb than R13

[wherm]

also remember...

If it's 95 degrees outside and you turn on the ac, you'll notice how cold it is because of how hot your body felt outside. If it's 70 degrees out, your a/c wont feel as cold. Just like jumping in a pool on a cool day, the water would feel warmer than it would if you jumped in on a 90 degree day.

[visualpoet]

My .02 as an universally certified HVAC tech.

Next time you take it to the shop to have it fixed, have them do a complete evacuation, vacuum check (it should sit hooked up for at least 15-20 minutes while they wait for it to lose pressure)and then a complete recharge. Systems that have lost any refrigerant have a leak, something that might not show up within a few minutes of charged and looking for the UV dye after a few minutes). If it took two lbs, the system was probably contaminated with air and moisture, and unless it was evacuated (most mechanics will just pump refrigerant into the system without pulling it into a vacuum first), it will cut down on the effectiveness of the system. Other than that, I think most of the other things I would have told you have been covered

[Best_siten]

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[visualpoet]

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