Hi
R69L is a drop-in for R502 with a few advantages/disadvantages added in.
1/Increase of system capacity by up to 30%
2/A slight increase in effeciency
3/an increase in condensing pressures (about 1 bar for 32 degC)
I would say on a system with a generously sized condenser and an adequate drive motor capacity this is a very quick way of increasing duty without adding plant.
On the down side, you may well be exceeding the system allowable pressure in some cases on the high side due to the increased pressure of the refrigerant at the designed condensing pressure and also by virtue of the increased kW's the compressor is sending the way of the condenser.
I personally like R69L, to me it is superior to say 404a, but the problem is it can not be fitted in any new plant installed in the EEC, so we are stuck with Mr leaky instead
Regards. Andy.