Auto A/C question non P-car

[Bob Kontak]

Originally Posted by cabmando

Tip the can upside down and you're charging with liquid. Do so VERY slowly or you can do damage. Right side up you're pulling vapor which is why you have to put the can in warm water to boil off the liquid to increase vapor pressure.

You can liquid "slug" the compressor and hurt the compressor if you charge with liquid into the suction side.

Yep, I just misunderstood what he meant by VS. Versus did not register so I was reading it from a totally different perspective.

I use scales and 30 lb tanks with the other standard equipment. I buy three tanks per year in a bundle buy and they cost about $80 per. You can't even buy the tanks anymore without an EPA 609 certificate.

I will invert tank on low side charge for a few seconds at a time on a colder day. Probably wrong but no problems yet.

[cabmandone]

Originally Posted by Bob Kontak

Yep, I just misunderstood what he meant by VS. Versus did not register so I was reading it from a totally different perspective.

I use scales and 30 lb tanks with the other standard equipment. I buy three tanks per year in a bundle buy and they cost about $80 per. You can't even buy the tanks anymore without an EPA 609 certificate.

I will invert tank on low side charge for a few seconds at a time on a colder day. Probably wrong but no problems yet.

Been doing that for years. Just go slow with the liquid and all is good.

[asphaltgambler]

Most modern mobile A/C systems are very efficient, very well designed and do more with less condenser area / evaporator area and smaller compressors. Speaking of compressors most all are variable displacement with a 'swash plate' where the displacement/ volume can change instantly and almost infinitely on demand.

[Zeke]

Originally Posted by asphaltgambler

Most modern mobile A/C systems are very efficient, very well designed and do more with less condenser area / evaporator area and smaller compressors. Speaking of compressors most all are variable displacement with a 'swash plate' where the displacement/ volume can change instantly and almost infinitely on demand.

Interesting to know. Likely my 2006 Chev 1500 doesn't have anything like that. It doesn't have climate control, just analog looking knobs and slides to blend warm air in with the cold. Terribly INEFFICIENT.

I remember the first car I attempted to charge with r12. It was a '63 Jag XJ6. I as delighted to find a can of r12 at the FLAPS so I went into it head strong and stupid. That was a piston type pump and I hydrolocked right off the bat. Scared the crap out of me.

It was a long time before I ventured into that foray again. I bought some gauges a few years later and still have them. They are not high pressure enough to handle the refrigerants of today. Reworking them cost as much as a mass produced import set sells for today. Plus I have all the adapters now. Just have to purge a bit between types.

[GH85Carrera]

As I only work on my own AC systems and time is not the main concern. I always charge with gas only. I have always been too chicken to try the liquid. So what if it takes me a extra few minutes to charge the system.

With the 911 I get crazy overkill trying to get all the moisture out of all that hose and 4 condensers and the evaporator. The Receiver Dryer is usually replaced if I open the system. So I vacuum and let it sit overnight. Then fill with dry nitrogen, vacuum for two hours, fill with dry nitrogen, vacuum again and let it sit overnight. If the pressures are the same, fill with refrigerant and done. Three days to charge a car is not a viable commercial operation.

There are some cool videos on the internet of ice forming in a vacuum. Instead of the water boiling off, it turn to ice and can stay in that form for a long time. A few cycles of nitrogen and vacuum should eliminate it all. It is a belts and suspenders thorough way to make sure.