This week I met with Michelle & Alex see below and we tested both air con systems.
I have a thermometer that measure internal and external temperatures (about 14 euros in DIY places) the external is measured by a sensor on about 1.5 metres of cable.
My air con on the cool setting blows air out down to about 15 degress (measured by putting the sensor in the grill in the lounge area) on the cool auto setting and my apartment starter to cool down from about 23 degrees. I know my apartment cools down as my son used it last week and it worked fine. It takes about 5 mins for air at 15 degrees to come through the vent. Note that ceiling vents take in the warm air and wall vents blow out cool air. In the heat mode this is reversed, the warm air comes out of the wall vents. Air circulation is always the same route.
In my Apartment I have two ceiling vents, one in the hall and one in the master bedroom. This is where the air is drawn into the system.
However I believe I still have a problem because in July, August my tenant could not get the temperature below 22. Basically I think the problem is that the unit is too small for a 90sq m sized apartment in peak Summer temperatures. I intend to contact the manufacturers and chech on the unit size, The Cool & Sein engineer did report in July this year that my unit was working but too small for the apartment.
The other apartment we tested did not cool the air, the fan and cool green LED lights just flashed on the wall controller.
I think Alex will issue an update when fixed.