Fan speed issue on Mitsubishi

[frank]

If the installer is due back to have another look, ask him to take the following readings both before it ramps up and then after the fan speed increase so that these can be compared against the data in the service manual:

Indoor coil temperature
Indoor air temperature
Indoor humidity
Outdoor temperature
Compressor frequency
Suction gas pressure

What position have you set for the swing flap?
Does the same problem occur when you select 'Econo' mode?
How long is the pipeline between indoor/outdoor units?

Sound pressure level	Indoor	Cooling (Hi/Me/Lo)	44/ 39 / 24
Heating (Hi/Me/Lo)	48 / 41 / 30
Outdoor	Cooling/Heating	51/ 51

The fan sound levels do not look high (compared to some)