I have a Toshiba System-3 inherited from the previous owner of our resale 5-room flat. Our main air-con usage is in the MBR about 6-9 hours every night. Recently, the blower unit in the MBR is not cooling as well as the other two rooms with the same settings. When I opened the MBR blower unit, I saw some rusting in the pipes due to condensation under heavy usage, while the other two units looked almost brand new. Since the outdoor unit is still functioning to provide good cooling in the other two rooms, I thought of swapping the blower unit from one of them with the MBR unit. When I spoke to my air-con service guy, he said it was a waste of time as each blower unit had its own compressor and swapping blowers would not work. I'm puzzled - I thought that in a System-3 all the blowers share a single compressor. If one blower is not functioning well due to rust in fan coils, then swapping it with a good one should work since the compressor is in good working order. Any air-con technicians in the forum care to comment?