Going back to R12...

[cbjukraine]

I'm going to convert my A/C system back to original, and I've got a few questions.

1) What kind of oil should I use and how much? My father, an HVAC tech of 40 years (not automobile), recommended I pick up some Suniso 3G refrigerant oil at a supply shop. Will this work and adequately lube the R4 compressor?

2) Do I need to use Nylog Red?

3) I plan on flushing the condenser and evaporator with acetone (cheap at Home Depot) and the rubber parts with solvent-based flush from one of the box stores. Followed with nitrogen to blow it out. Good idea?

4) I'm hoping to leak test with nitrogen by pressurizing to 100 PSI, but i don't have a sniffer or any refrigerant that is legal to vent for leak testing. I was thinking I would leave it overnight and see what the pressure was in the morning. I have one of those Robinair digital manifolds. Suggestions?

Thanks!

[Graplr]

All that sounds pretty good to me. If you flush it you can use Mineral Oil (as is what the norm is for R12) or you can use Ester oil (which is compatible with both R12 and R134a). If I new I was sticking with R12 I would probably use Mineral oil.

Yes, Nylog Red is for R12.

[Air&Road]

It sounds like you have a good handle on the project. I'm not familiar with that specific oil, but if it works well with R12, I'm sure it will serve you well in the correct amount.

Your wise for sweeping and pressure testing with nitrogen. If you have a sniffer, put an ounce or two of R22 in with it and you can REALLY do some thorough system leak testing.

Good luck with it and keep us informed.

[anghrist]

Suniso 3G is recommended for the Sanden compressors when using R12. I don't know of any reason to not use it in an R4.

[vstech]

I'd pump it up to 200psi for leak testing with pressure alone.

if you can source a sniffer, 4oz of R22 is legal for detecting a leak and venting.

what do you think of the digital gauges? I'm leaning towards the fieldtest set... more gadgets... $350 not bad when considering the goodies included.

[DeliveryValve]

Originally Posted by vstech

I'd pump it up to 200psi for leak testing with pressure alone.

if you can source a sniffer, 4oz of R22 is legal for detecting a leak and venting...

What do you pump it up with. Air?


R22 is expensive... I guess 4 ounces won't break the bank. Is there any other possible alternatives for sniffing?



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[DeliveryValve]

Originally Posted by vstech

I'd pump it up to 200psi for leak testing with pressure alone.

if you can source a sniffer, 4oz of R22 is legal for detecting a leak and venting.

what do you think of the digital gauges? I'm leaning towards the fieldtest set... more gadgets... $350 not bad when considering the goodies included.

Hey John,

I happen to run across this on the EPA website.

The Clean Air Act does not allow any refrigerant to be vented into the atmosphere during installation, service, or retirement of equipment. Therefore, R-22 must be recovered and recycled (for reuse in the same system), reclaimed (reprocessed to the same purity standard as new R-22), or destroyed.

What You Should Know about Refrigerants When Purchasing or Repairing a Residential A/C System or Heat Pump | Ozone Layer Protection - Regulatory Programs | US EPA


"any" appears to be an absolute here. Just so that we all don't get in trouble for venting, do you have a copy of the reg about using it for testing?


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[vstech]

pumping it up should ONLY be done with a "DRY" gas. N2, CO2, Argon, etc. ***NOT OXYGEN!!!!!!!***

if you do not put a halide/CFC/HCFC in for the sniffer to sense, it will not find a leak.

IF you have a reclaimer, you can use any refrigerant... if you do not, 22, is the least expensive, and damaging to the ozone, according to EPA.

if you don't wanna use 22, you could use pure N2, and an ultrasonic leak detector... but they are pricey!

[Ether]

Where do I find fittings to get from the CO2 can to the Schraeder fitting on my gauges?

[vstech]

anyplace you get the cylinders should have regulators. from simple dual valve to full on flow meter regulators. you attach a 1/4" male flare fitting onto the output of the regulator, and hook the gauges to that.

[Air&Road]

VS,

Can I use the CO2/Argon gas that I use for my MIG welder in place of nitrogen for leak testing and system sweeping?

[vstech]

yup.
you can even use the regulator you have, and just undo the hose connector, and thread in a 1/4" male flare adapter for your manifold hose set.

[Air&Road]

Yes, I understand the plumbing part, but this gas will work as well as nitrogen for combining with R22 for leak checking?

[cbjukraine]

I bought both of these today, not sure which is best to use...

[vstech]

best would be the mineral oil. R12 CAN use ester, but it's not the best. and why put all that dye in your system if you have already leak tested it! (you have leak tested it before you fill with R12 right???)