Air Conditioning R12 & Cooling Unit Removal

[ARCHINSTL]

Dumb question, I know, but...
How does one tell if there is any R12 left in a system?
The compressor was non-operative when I got Goldie back in '05; it was locked up virtually solid and the pulleys were pretty rusty from disuse.
I'm pretty certain that there is probably no refrigerant left, but I want to make certain, as I want to remove the cooling unit from the duct system to both clean the heater core and also improve the air flow through the whole system.
What with the costs involved, I rather doubt I'll ever have operating AC in the car again.
So - while I don't see any bubbles (or ANYthing, for that matter) in the little sight glass - is there any other way I can be positive there is no refrigerant left? I know it is not a good idea to just open a valve and vent it to the atmosphere (I also don't want to get a snoot full of some chemical - well, not this chemical anyway...).
Thanks.
Tom M.

[keith]

Use a tire pressure gauge over the fill valve just like checking a tire. If there is pressure, there is freon.

[Neu]

Remember to drain it properly, which usually requires going to a mechanic and getting it drained.

[ARCHINSTL]

Thanks, keith and Neu -
Hopefully, there will be none left, so I won't have to pay someone.
Hmmm - if R12 is so valuable nowadays - what do HVAC people do when they change out a system? Dispose of it - how? Sell it / reclaim it for folks who still need it?
I live in an old house with a 40 year-old AC system that still "blows really cold," - and has an EER of probably 0.2 - but the house will be torn down next year and the lot turned into yet another McMansion (not mine - I'm moving to some place with a GARAGE!). Is the R12 in the system worth anything?
Tom M.

[Neu]

This is how it worked when I worked in a mechanics shop.

When you "recover" the refrigerant, it goes into a storage bottle, when it gets full it lets you know.

You then give that bottle to the guy who sells you the new refrigerant(about 100 bucks) and you get a discount because you're recycling the old refrigerant. I dont know what they do with it after that.

[terkill]

test

[takza]

Is the R12 in the system worth anything?Tom M.

My guess is a fair amount...gets recycled?...but they are also required by law not to release it into the air.

[splatterdog]

R12 is coming down and is way below it's peak. Deals abound on craigslist, as usual. With the scrap happiness these days, the number of cars using it has dropped dramatically reducing demand. There is still alot around. I doubt R12 cars will outlast R12 supplies.

Of course I "follow the rules" by not venting. But for me that's like letting money blow away. I'm still kinda wondering how something heavier than air makes it up so high in the sky.

Try craigslist services. You might find someone like me who helps people like you. Maybe a shop might take it off your hands,hopefully without charging you for it! Keep in mind there is probably little to no freon left in the system which would make it a big waste of everyone's time to recover a trace amount.

[Typrus]

Sometimes you can find shops who will recharge your system with R12. Which blows colder than R134a by the way. I know of one in the area who does here, but beyond that... (shrug)

[ARCHINSTL]

Well, I tested the "Schrader-type" valve; my various Schrader gauges types did not fit - and I have many different types left from the bike shop. The AC fitting was too large for the gauges.
So - I just depressed the actual valve - and nothing escaped or was heard to escape - so it's empty.
And now - at some none-too-relished point - I will remove the evaporator from the cooling unit; this should dramatically improve the airflow and bring it to where I remember the then-new, non-AC, '83's flow was. And perhaps with the addition of the new thermostat (still undecided on a brand), the quality of the heat will increase along with the quantity.

Thanks to all for advice.
Incidentally, before I sell the house, I'll see if anyone wants to buy the R12 - who knows ? ? ?
Tom M.

[Typrus]

I thought houses used R22....

When I pulled the evaporator from my 84 I didn't notice much difference.
However, our 81 Corolla Tercel's heat is AWESOME.... No A/C

[ARCHINSTL]

Could be - someone (not a HVAC person) told me R12 many years ago, so I went with that.
I dunno.
Tom M.