I replaced the evaporator coil in a 4 year old Daikin 12K mini split. I have pressure tested with nitrogen and vacuum tested, should be ready to charge. Then I had a thought. If this were one of my vehicles and I replaced a part there are charts on how much oil to add to the system. I have looked all over the net and see no reference to adding oil to a R410a mini split. Am I missing something??
Add oil when replacing mini split evaporator coil.
- Thread starter jjrbus
- Start date
Yeah, when you lose freon you lose a little oil vapor along with it. But there's really no way to be able to measure how low on oil you are, so you don't know how much to add.
With old 22 systems - if the compressor needed to replaced - you could flush out the rest of the system, change filter/driers, make sure all the ports are clear and everything's leak free. Then, the oil charge in the new comp would be enough for the good clean system. But I can't vouch for that procedure with the newer freons and synthetic oils.
With old 22 systems - if the compressor needed to replaced - you could flush out the rest of the system, change filter/driers, make sure all the ports are clear and everything's leak free. Then, the oil charge in the new comp would be enough for the good clean system. But I can't vouch for that procedure with the newer freons and synthetic oils.
Raisedonadeere
Well-known member
I have a 4 year old Mr Cool 12K wall wart unit that developed a leak in the inside head (condenser) which was replaced on warranty. The replacement was hooked up and refrigerant weighed in with no oil added by the service tech. It is a 410A unit. Running fine for about 4 months now.
10-4 If a compressor fails due to a mechanical issue (leaky or blown valve, bad bearing, etc.) without a burn-out, then just R&R the comp should be fine. It's only after a burn-out (high operating temps or pressures, clogged cond coil, shorted comp winding, etc.) that a flush and oil addition is in order. Thanks for making me clarify my response.
Older mineral oils had a maximum operating temperature of around 300 deg F before they started oxidizing and breaking down. The newer synthetic oils raised that upper limit to around 400 deg F. (One thing that I like about the synth oils).
How to know if temps are getting near the upper limit of your system? If I suspected a possible overheating situation I'd hook a temp probe up to the hot gas line about 6-12 inches away from the compressor head. If I read 275 deg or higher then I assumed the oil in the head near the valves was nearing 300 deg (For an older, mineral oil system). I'd take steps to lower the temp, and inform the cust that there's a likelihood of a comp failure in your future because I didn't know how long it had operated like that. Since hermetically-sealed compressors don't have drain valves to remove tainted or damaged oil and refill there's not much you can do to fix that.
Last edited: