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Brians256 · 08-27-2002, 04:35 PM

You can do it fairly well, from what I've heard, but it requires massive effort.

The tubing itself is not difficult. Simply flush the system repeatedly with a solvent and an oil filter. Since the oil is soluble (on purpose!) within the refrigerant, you can run R12 through the system until the mineral oil is gone.

The compressor is more difficult. Some people recommend cracking open the compressor and doing a detailed cleaning before sealing it back up. Others recommend "blowing" the oil out in a manner similar to (above) cleaning the tubing out.

I'd have to do more research before I trusted myself to do it, though. For instance, evacuating a system takes minutes with a good vacuum pump. But, getting the water out requires a 29.75" or better vacuum for up to 8 hours before the ALL of the water can be safely said to be gone. Do you believe that most HVAC mechanics spend that much quality time on their retrofits? Oh, and the recommendation is to change vacuum pump oil for every 10 hours (I think that was the number, double check it of course) of vacuum pump usage.

Doing it right is a massive pain, which is why it is practical for the home hobbyist like us, but not for most of the industry out there. Time is money.

08-27-2002, 04:35 PM	#175
Brians256 Pro/Staff Join Date: Oct 2001 Location: Klamath Falls, OR Posts: 1,439	You can do it fairly well, from what I've heard, but it requires massive effort. The tubing itself is not difficult. Simply flush the system repeatedly with a solvent and an oil filter. Since the oil is soluble (on purpose!) within the refrigerant, you can run R12 through the system until the mineral oil is gone. The compressor is more difficult. Some people recommend cracking open the compressor and doing a detailed cleaning before sealing it back up. Others recommend "blowing" the oil out in a manner similar to (above) cleaning the tubing out. I'd have to do more research before I trusted myself to do it, though. For instance, evacuating a system takes minutes with a good vacuum pump. But, getting the water out requires a 29.75" or better vacuum for up to 8 hours before the ALL of the water can be safely said to be gone. Do you believe that most HVAC mechanics spend that much quality time on their retrofits? Oh, and the recommendation is to change vacuum pump oil for every 10 hours (I think that was the number, double check it of course) of vacuum pump usage. Doing it right is a massive pain, which is why it is practical for the home hobbyist like us, but not for most of the industry out there. Time is money.