Airconditioning problem Advise Please

[Saltydog]

I have an 1982. I am replacing the AC compressor. When I went to buy one a my local parts store the clerk ask me if i wanted a switched model type or the non-switched one. The sales clerk told me that wheather it was switched or nonswitched made no difference that the switched was a safety feature of some kind??? I did not know. Today I called my local Chevy dealership parts department and they only listed one type and did not mention switched or non-switched.
Does anyone know about this switched verses non-switched type compressor??
Which do I use for my 82.
I plan to put the Enviro Safe name brand of gas in it.
Thanks for any help.
Saltydog

 

[zackm58941]

I'm not sure what they mean about swichted or non-switched. Are they talking about a pressure switch or something, the system already has one so not sure.

Make sure you use a recovery machince to pull all the R-12 out of the system and hold a vacuum on the a/c system for 10-15 mins. Also, find the right amount and type of oil the system requires along with the correct amount of refrigerent to put in and don't mix R-12 with any other type of refrigerent, like R-134a. They are two different anamals and don't mix. I believe it will sludge up the lines if those two are mixed. Good luck.

 

[photovette]

Enviro Safe is a mixture of liquid propane and butane. Do you really want 3lbs of liquified petroleum gas in your condenser coil? It's illegal for automobile use; if you get in a wreck and it ignites, your insurance company will just laugh at you--they know all about it too. They'll also drop your policy if you tell them you have it in your car--kinda makes you wonder about the stuff.

If you can, get someone to charge R-409a, that's the very best replacement refrigerant--it works much better than R-12 even. I have it in my 1977 'vette and the cabin temperature behind the seats reaches 55F on a 94F sunny day. The best way is to find a refrigeration service truck and ask the tech if he does side jobs--the answer will be 'yes.'

R-134a has a much higher head pressure than R-12, so your condenser will put a much higher load on your cooling system. But it's cheap and easy to obtain.

 

[1978L48jafo]

Saltydog,
I am using the enviro safe refrigerant in my daily driver and it works great and IMO at a reasonable cost. I hope to switch my vet over this weekend the R134a never has worked worth a darn even with even after a complete rebuild and larger blower & cage. The stuff is also denser so one can seems to cover what originally took three cans. If you have not already check out their website I placed a link on a post last week. There are several comparison tables and testing results.
John

 

[photovette]

Enviro safe works just fine; no argument there. But before people use it, they should be aware of exactly what it is.

I will make one point, I've seen many rear end collisions that didn't damage the fuel tank. However, very few front end collisions manage to spare the condenser coil. I don't care how well it works, I don't want liquid petroleum gas released into my engine compartment. Front end collisions are common. Refrigerant hose ruptures are an eventual certainty in cars the age of ours. You will note that the rubber refrigerant lines are right next to the exhaust manifold and spark plugs.

Here is what Enviro Safe is:

"R12a (Enviro Safe) is what is called a 'natural refrigerant' because it is a mixture of stable organic compounds, which have been around forever (?). It is a mixture of stable hydrocarbons to which the name 'paraffin's' was given in the early days of the study of Organic Chemistry. The mixture consists of approx. 40% butane, 59% propane and 1% ethane.

It is well known that ethane, propane and butane are flammable in air and, when mixed in certain proportions with air, will burn with explosive speed. Nevertheless, propane and butane were used as refrigerants, along with ammonia, carbon dioxide, and sulphur dioxide, before the development and commercial use of freons in the early 1930's. It was an explosion involving propane in a school air conditioning system, which resulted in the death of a number of students, which lead to the banning of the 'natural' (flammable) refrigerants, in favour of the 'freons' in North America."

 

[Saltydog]

Thanks guys for all the advise. To be frank the Enviro Safe gas (HC12a) scares me. Mainly because the folks in my neck of the woods mostly don't know what it is and the ones that do say that 134a with the correct installation is just as cold.

I thought that I was on to something good but I guess I'm getting "cold feet".
Thanks for the help.
Saltydog

 

[BLACKDOG]

photovette - am I understanding your post right ... that R-409a can be used as a replacement refrigerant for R-12 ?? I'd really prefer not having to convert over to R-134 if there is another option out there. Thanks.

 

[photovette]

There are many R-12 replacements. I've tried R-134a, R-414b, R-416a, R-408b, R-404a, HP-81, HP-61, and R-409a in my 'vette. I design ultra cold refrigeration systems, so I have many types of refrigerants in my shop.

R-409a works far and away better than the others. Much, much better than R-12 even. My '77 'vette's a/c puts the one in my wife's Camry to shame!

Now, R-414b & R-416a seems to work just fine in 1977L-1982 systems (ccot) and are easier and cheaper to obtain. If you have a post '77 'vette--go with the R-416a first.

 

[GerryLP]

I had the A/C in my car converted to FR-12. It's like R-12 but without the controlled additives and it is approved. No special orifice nor seals are needed. I even paid for them to add the dye which makes it easy to detect leaks. The A/C seems to work fine and it cools fine too.

 

[photovette]

FR-12 is another name for R-416a.

I have great success with R-416a in my '91 Ford van and other CCOT system cars, but not in VIR systems. VIR systems measure the evaporator pressure instead of evaporator temperature. So, the pressure of R-12 at 34F is not the same as R-416a at 34F. I'll bet you have a 1977L or newer 'vette. For 1977E or earlier, R-409a is the ticket.

Check what kind of system you have and let me know.

If can use FR-12 (R-416a) you're better off because it has a lower head pressure than even R-12. This relates to better gas mileage and lower condenser temperatures.

 

[BLACKDOG]

This is quite a learning experience !! After spending a couple of hours online last nite, I found quite a few possible options to R-12.

Freeze-12
requires different fittings/labels
no system flushes
use 90% of Freeze-12 in R-12 system

Freezone (RB-276)
needs no system flush or addl lubricant
Barrier hoses (?) not needed

AutoFrost(R-406a)
no oil change
cannot be vented - needs recovery
must be charged as a liquid

HotShot(414b) - no specifics given

McCool Chill-it
no retrofitting
only requires 80% of R-12 capacity

All I can say is ... Yeow !!!

My Vette is a 1980 ... and I can't honestly say whether it's a CCOT or VIR system ... and it's 100 miles away getting an engine transplant right now.

 

[Tom73]

Here is what Enviro Safe is:

"R12a (Enviro Safe) is what is called a 'natural refrigerant' because it is a mixture of stable organic compounds, which have been around forever (?). It is a mixture of stable hydrocarbons to which the name 'paraffin's' was given in the early days of the study of Organic Chemistry. The mixture consists of approx. 40% butane, 59% propane and 1% ethane.

It is well known that ethane, propane and butane are flammable in air and, when mixed in certain proportions with air, will burn with explosive speed. Nevertheless, propane and butane were used as refrigerants, along with ammonia, carbon dioxide, and sulphur dioxide, before the development and commercial use of freons in the early 1930's. It was an explosion involving propane in a school air conditioning system, which resulted in the death of a number of students, which lead to the banning of the 'natural' (flammable) refrigerants, in favour of the 'freons' in North America."

Can you provide a source for this quote?

This is quite a learning experience !! After spending a couple of hours online last nite, I found quite a few possible options to R-12.

Freeze-12
requires different fittings/labels
no system flushes
use 90% of Freeze-12 in R-12 system
The use of any refregrent other than what came in the car requires the use of different fittings and labels.

Per EPA Web site (http://www.epa.gov/spdpublc/snap/refrigerants/macssubs.html) Freeze-12 is a blend of 80% HFC 134a and 20% HCFC 142b. Hummm, 80% 134, may as well go with regular 134.


Freezone (RB-276)
needs no system flush or addl lubricant
Barrier hoses (?) not needed
Freezone is almost identical to Freeze 12 but is off by 1%, 79% 134a and 21% 142b.

AutoFrost(R-406a)
no oil change
cannot be vented - needs recovery
must be charged as a liquid
AutoFrost is a wild blend of 51% HCFC 122, 28.5% HCFC 124, 16.5% HCFC 142b, and 4% Isobutane (Note that HCFC 122 is the refregrent that REQUIRES the use of barrier hoses)

HotShot(414b) - no specifics given
HotShot is another wild blend and is very close to AutoFrost. It is 50% 122, 39% 124, 9.5% 142b, and 1.5% Isobutane.

McCool Chill-it
no retrofitting
only requires 80% of R-12 capacity
Chill-It is AutoFrost

All I can say is ... Yeow !!!

Here is an interesting quote from the EPA site:
Many refrigerants, including R-401A (made by DuPont), R-401B (DuPont), R-409A (Elf Atochem), Care 30 (Calor Gas), Adak-29/Adak-12 (TACIP Int'l), MT-31 (Millenia Tech), and ES-12R (Intervest), have not been submitted for review in motor vehicle air conditioning, and it is therefore illegal to use these refrigerants in such systems as an alternative to CFC-12.

Like most, I would like to find a good cheap and legal refregrent to replace R12, but as you can see there does not appear to be much out there.

 

[BLACKDOG]

thanks Tom73 and photovette for filling in a lot of the blanks, especially since this is all unexplored territory for me.

Is the "retrofit" process going to be rather extensive ? ... or by going with either FR-12, FreeZone(RB-276), or Freeze-12 (no R-22 in these) will I be minimizing it at all ?

Guess I'm fishing for the least expensive process ... if there is one.

Or should I just surrender to the situation and move to Lake Tahoe instead. It rarely ever reaches the mid 80's up there !!

 

[photovette]

Okay, as far as a certain refrigerant being legal--how many of your post 1974 'vettes have no cats and true dual exhaust systems? Anybody remove their emissions stuff? Anybody exceed the speed limit on the highway? Well, you're all in violation of federal law and subject to heavy fines! Bad!

Now, if I said that a certain refrigerant will make your 'vette faster and/or increase gas milage, there'd be no such quibbling! R-416a will increase milage and speed due to a much lower head pressure.

However, R-416a won't work well in POA and VIR systems. R-409a (which is what a Ferrari has in it's a/c system by-the-way) works better than all of them in pre-CCOT systems.

This is how my trial and error testing turned out. My 'vette is so cold now my wife turns the vents away from her before I even start the motor.