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General Information => General => Topic started by: Vincent Waldon on October 12, 2008, 09:23:01 pm

Title: Discharging an R134a A/C system ??
Post by: Vincent Waldon on October 12, 2008, 09:23:01 pm
I'm parting out an MK3 Golf and would like to hang on to a couple of the more expensive A/C pieces in case they are useful to someone... the compressor, for example.  

It's a R134a system.  The Bentley is pretty vague about discharging the system... they tell you to do it lots of times, but also warn you that it is dangerous, can cause fires, gout, the plague, and force Sarah Palin to lose sight of Russia.

I've eschewed A/C until now (not that hot in Edmonton) and don't know much about the practicalities... reading some of the operating pressures gives me pause, but with the system not running perhaps not much to worry about ?

What I'm interested in learning is suggestions from anyone with R134a A/C experience on the safe way to vent the system so I can disassemble and then dispose of the shell safely.  The car is engine-less and wheel-less so no way to get it to a shop.

thanks in advance,


Vince
Title: Discharging an R134a A/C system ??
Post by: Powered by Spearco on October 13, 2008, 12:31:05 am
Well you could get an A/C machine or just open up the covers and let it out  :roll:. I know its not right, but what can you do at this point  :cry:. The car is immobile  :( .
Title: Discharging an R134a A/C system ??
Post by: blkboostedtruck on October 13, 2008, 09:21:44 am
use a baby's diaper when you unscrew that tire like valve hold the diaper around it and that should catch most particles in the diaper! then just put diaper in a plastic zip lock bag and dispose of!
diaper is pretty absorbent! what do you think of that idea?
Duane
Title: Discharging an R134a A/C system ??
Post by: zukgod1 on October 13, 2008, 09:43:04 am
The "proper" way is to have is evacuated with a machine.

Just cracking the system open and venting to the air is bad.

I'm not saying it's not happened to me but it shouldn't.

If you cant get it to a shop to get it evacuated your choices are limited.
Title: Discharging an R134a A/C system ??
Post by: saurkraut on October 13, 2008, 10:51:56 am
I thought R12 (Non-flamible, cooled Really Good)was trashed because it ate the Ozone layer, and R134a (flamable, cools kinda good...) was supposed to be Ozone safe?

Whats up with that? :?
Title: Discharging an R134a A/C system ??
Post by: lord_verminaard on October 13, 2008, 11:04:34 am
That was my thought too.  Neither one is good to breathe, but R12 is supposedly much more dangerous.  I've always vented 134 to atmosphere, just make sure you are in a well-ventilated area.  This almost always happens when I re-charge AC systems with a kit that I have.  Most of the time the car won't take the full can of refrigerant so you have to vent the remainder of the can somehow.

Brendan
Title: Discharging an R134a A/C system ??
Post by: zukgod1 on October 13, 2008, 11:29:29 am
You can vent either one but it's not a good way to do it.

134 isn't safe for the ozone just not as bad as 12.

It SHOULD be evacuated VIA machine.
Title: Discharging an R134a A/C system ??
Post by: clbanman on October 13, 2008, 12:11:59 pm
We use R134A on our trucks at work, and we have to record all charge weights and account for every evacuation.  As stated previously, R134A is not ozone safe, just not as bad as R12.   I don't know about your area, but around here you can get mobile outfits to come out to evactuate or recharge an A/C system.    Read the msds in this link for safety information related to handling/breathing the gas: http://ww2.ramapo.edu/libfiles/HR/Environmental_Health_and_Safety/MSDS/Facilities/HVAC/134a.pdf
Title: Discharging an R134a A/C system ??
Post by: saurkraut on October 13, 2008, 02:03:51 pm
Makes me wonder about the 'badness' of r12 vrs r134.  I kind of recall r134 being called the big solution to ozone depletion.  While r12 was darned right straight to heck.

Wouldn't it be interesting, in a crappy sort of a way, if it turns out that r134 is just as bad as r12 ozone wise, but doesn't cool as good, and is flamable.
Title: Discharging an R134a A/C system ??
Post by: Kudagra on October 14, 2008, 12:51:34 am
R12 was only suddenly deemed bad when DuPonts patent ran out..but guess who holds the patent for R134a.

Imagine being able to sell a product for 50 years and as soon as you dont have a monopoly on it you make your "friends" make it illegal and you sell them the only replacement  for the next 50 years.

Oh yea...Im quite bitter.
Title: Discharging an R134a A/C system ??
Post by: jtanguay on October 14, 2008, 01:26:57 am
well the R12 actually destroys the ozone layer...  a small amount of of the cfc's can destroy a substantial amount of ozone before its lifespan (which is about 100 years or so?) it breaks apart the 3 oxygen atoms that the ozone is made of.  so that 50 years of R12 is having a lasting impact, of which i believe is one of the sole reasons for this global warming.  CO2 isn't doing jack ***!  get rid of the ozone, and the full might of the sun is now unleashed!  unfiltered.  and guess what? there's a huge hole right over the arctic! probably a good reason why its melting...

now back to r134a - just don't let anyone see you discharge it.  it is illegal here in Canada.  i highly doubt it's bad for the environment.  its comprised of 3 different gases, but i forget which they are.  if you were to have a big enough leak while under pressure, i'd imagine that it might auto ignite like diesel.  but the systems normal pressure when not on should be around 30-40 psi... maybe even a bit more or less...  oh yea.. don't breathe it in!!!  :lol:
Title: Discharging an R134a A/C system ??
Post by: clbanman on October 14, 2008, 05:46:56 am
Danger of 134A is primarily frostbite due to exposure to skin or eyes. Breathing it in is not an issue in most cases as the msds says it has low toxicity, so unless you are in a closed space, there shouldn't be a problem.  It won't autoignite unless compressed above atmospheric pressure in the presence of oxygen.
Title: Discharging an R134a A/C system ??
Post by: jtanguay on October 14, 2008, 01:00:47 pm
http://yarchive.net/ac/r134a_lethal.html

i'm using the HC-12a hydrocarbon refrigerant from now on...
Title: Discharging an R134a A/C system ??
Post by: Mark(The Miser)UK on October 14, 2008, 03:33:29 pm
If the car had wheels on you could take it outside and have an accident. Then it would be legal wouldn't it?
Title: Discharging an R134a A/C system ??
Post by: Dakotakid on October 15, 2008, 01:54:53 am
So did you catch anything in that diaper, Vince?????
Title: Discharging an R134a A/C system ??
Post by: Vincent Waldon on October 18, 2008, 07:21:00 pm
Thanks for the input everyone.

I'm one of those who is too dumb to know if climate change is man-made or not, but thinks I'd feel even dumber if it turns out that we could have made a difference and we chose not to..  so am trying to do this right.

I found a Red-Tec tester for 3 bucks that you use on the low-side port to check for proper oil in the coolant... figured it was a safe way to sample the system.. got a very tiny psssst and then nothing.

So, if the low pressure side is empty is it safe to assume the hi-pressure side is empty as well ??  OK to disassemble ??  I'm thinking the hi-pressure side is only high when the compressor is running ??
Title: Discharging an R134a A/C system ??
Post by: jtanguay on November 06, 2008, 09:55:13 pm
Quote from: "Vincent Waldon"
Thanks for the input everyone.

I'm one of those who is too dumb to know if climate change is man-made or not, but thinks I'd feel even dumber if it turns out that we could have made a difference and we chose not to..  so am trying to do this right.

I found a Red-Tec tester for 3 bucks that you use on the low-side port to check for proper oil in the coolant... figured it was a safe way to sample the system.. got a very tiny psssst and then nothing.

So, if the low pressure side is empty is it safe to assume the hi-pressure side is empty as well ??  OK to disassemble ??  I'm thinking the hi-pressure side is only high when the compressor is running ??


yep if the low pressure side is empty then the high side is as well.  although when the system is running the low side can be 20 psi and the high side can be about 150-300-ish.  that high pressure can take a little while to equalize... i would estimate at about 10-20 minutes.

the ozone layer protects the earth in that it blocks a lot of the harmful radiation from the sun.  now with the old refrigerant, it actually destroys the ozone, letting more radiation from the sun in.  this is probably the main reason for a lot of the skin cancers and the earth heating up. r134a doesn't contain any ozone depleting gas (or so they say) and besides the hydrocarbon stuff, theres some new refrigerants available mostly for industrial use.

so if its like non ozone depleting like they say, then there should be no problem with releasing it to the atmosphere... just don't let anyone see you do it.  R12 is a different story though...

you can just get two cans of duracool... they already come with oil mixed in.  you just need to shake the cans like crazy to make sure the oil gets in the system.  that way you don't need to worry about low oil situations.