Dr.J

Greetings everyone! Has anyone tried the conversion from r134a to r12a, in your 997 and, if so, what was/is the outcome?

From all I’ve read about r12a, it seems like an improvement over r134a?

Thanks,

john

Brainz

I believe R12a has not been in production for 25 years or so due to CFC/ozone concerns. I'm sure you can buy it (somewhere), but it will be more expensive than readily available 134a which replaced it. Many older r12 systems have been converted to 134a for cost/convenience purposes, but 134a does not run as efficiently in a systems designed for r12, so many regard 134 as inferior.

While R12 systems worked great so do modern 134a systems like the one in the 997s. Switching to r12 sounds like an answer in search of a problem. If you're system isn't cooling enough, you should have it checked by a specialist.

doclouie

Last I remember is that R12 was about $125 per pound. R134a is about $5 a pound. Have a specialist look at your system. My 997.2 is the coldest car I have ever owned. They way overdid the A/C system in my opinion, which I love as an engineer.

CAVU

John,

If the R12A is also HC-12A (https://en.wikipedia.org/wiki/HC-12a), which my guess it is, I would not use it in any of my cars and I do not know anyone who has. Too many down sides and R134 is readily available. I wonder is there are any gauges setup for R12A. My biggest concern is the thought of having a combustible gas (a component in the R12A) that could get loose in the cockpit or the engine compartment. In other non porsche forums, some bring up the gasoline combustibility, but we are now talking about two different designs. modern cars are designed to try and keep the fuel contained during a crash and kill electrical circuits, etc. I do not recall HVAC systems having to be designed for that level of safety.

Curious as to what your goal is.

Dr.J

Yes, CAVU, HC-12a and R-12a are one and the same. Apart from the combustible potential, 12a seems to have it over 134a in every way, operates at a much lower pressure, is much colder (35 - 40% of 12a is as cold as 100% of 134a), reduces stress on the pump and system, overall, the molecules are much larger than 134a and less prone to leaking. The literature is impressive. I guess it boils down to how much “real” risk is involved?

Khloesdad

This is a good post. It's my personal opinion but R12 is great. It is still available but only through a licensed dealer. Note: When if you do convert from 134 to R12, you must get all the PAG oil out of the system. R12 requires mineral oil and "does not' mix well with PAG oil.

4Driver4

Funny thing is, the OP did not mention R12, yet somehow this thread is about R12...?

Dr.J

No, Khloesdad & 4Driver4, NOT R12, we’re talking about R12a, which is what HC-12a is branded as, at least here in Canada.

4Driver4

Yeah. That was my point.

Khloesdad

Sorry guys.

ejabour

I live in south florida and think the AC in my car is phenomenal. This is a system designed to use a particular refrigerant, r134a.

The expansion valve, condenser, compressor, etc are designed based on this refrigerant. I do not see why anyone would attempt a conversion.

Brainz

If I had an r12 system that needed to be refilled, I would have no issues trying HC-12 given it's availability and compatibility with r12.

But converting a correctly engineered 134a system (like the one on the 997) to use HC-12 makes no sense to me.

63mercedes

Sweet there's hope for me. I got a car in november and I thought the ac was always a little weak. I may just need a charging, but that means theres a freon leak because it's a sealed system? I always heard porsches had terrible ac and I kind of thought that was normal. I live in south florida also and was real surprised the ejabour finds it sufficient and doclouie in texas says his is ice cold. I think i need to have mine checked.

Brainz

I'm in Houston. Have owned two 997s. Both have had excellent AC.

s85b50

https://www.ebay.com/itm/12a-Refrige...2/283584703849

Does anyone know if this is the HC-12a?