Freon alternatives

Ok did a lot of reading, 2-3 hours worth on the topic with lots of mixed results and contridicting information.

Basically I have a R-12 system that's out so I want to recharge it. Well I want to DIY, which requires a converstion ... however I heard that R-12 and R-134a are incompatible, requiring a flush and other steps possibly out of my level (vacuum, evacuation, etc) ... Additionally, I'm reading tons of stuff that says R-134a could damage my system due to higher compression requirements. Is this true? I'm doin this on a 92' Rodeo, 3.1L V6.

So I came across alternatives that claim compatibility with R-12 and similar compression requirements.

1) If my system needs a recharge, will I still have to have it evacuated and vacuumed by a A/C technician, if I stick with a compatible recharge kit?

2) From what I understand, the product Freeze12 is the only alternative that does NOT require use and installation of a barrier hose. Is this correct still?

3) Has anyone used the following with results similar to R-12 (as I also read R-134a doesn't work as good either) Free Zone, Ikon-12, R-406A aka McCool, Autofrost or Chill-It, Hot Shot aka Kar Kool, GHG-HP.

4) Anyone heard of Enviro-safe @ www.btt.org/ES.html and is it safe to use? Its not listed in EPA's SNAP list

there are three big problems to DIY A/C work.
1. skill - it is very easy to destroy the A/C system if you don't know what you are doing.
2. equiptment - recovery machines and gauge sets cost money.
3. its illegal to work with refrigurent without a EPA 609 certification.

however there is no big problem working on a discharged system. have the system recovered by a shop, do the repairs and retrofit, then have the system evaculated (1 hour minumim perferred for retrofits), leak tested, and charged

i wouldn't use anything not SNAP approved. R-134a is about 80% as efficenct as R-12. barrier hoses are required with use of R-22 or any blend with R-22. check http://www.epa.gov/ozone/snap/refrigerants/macssubs.html#otherinfo for makeup to see if R-22 is part of the blend. personially i would just go with straght R-134a, blends can be troublesome, R-134a is more wide spread and easier to work with. also the pressure difference is not that great. also R-134a(or a blend) may require different hoses then R-12, not a barrier hose, just a hose compatible with R-134a. your vehicle may already have these hoses installed. if the hose is R-134a compatible, it should have a white stripe on it. you want to replace the Receiver/dryer, FOT(if applicible), and oil(depending on which refrigurent you use). you may also want to call your dealership/manufactior to see if any other parts need replaced for the retrofit.

I used one of those converter kits from AutoZone 4 or 5 years ago on my 94 Cavi. It consisted of an adaptor for the valves and some new O-rings. The R-12 was gone due to a bad compressor. I installed the new comp. and drier, filled it with R134A and have been cool ever since. As for the hoses (I heard they would not work) they seem fine. If they blow this afternoon I got my money out of them. Total cost was about $150 for coomp/drier and $12 for the conversion kit. throw in som R134A and you are done. Easy. Good Luck.

r-134a and yes you do need to have it vacumed and recharged by a tech