It is a motor with pipes. It is the exhaust fan unit for our apartment.
There is one of these inlets in the bathroom, one in the toilet and one in my en suite. When we moved to the Highrise, we had no idea about the system, but the bathroom and my en suite have two lights, one halogen and one recessed downlight. The toilet only has a downlight. In the bathroom and ensuite, the halogen lights are separate, but the downlight light switch turns the fan on, as does the toilet downlight.
Some parts of the Highrise ceiling are lower, to allow for the ducting, as you can see in my bedroom with my en-suite just to the left.
Back in the bathroom where the laundry is too, the clothes dryer air outlet joins the flexible tubes to be vented outside.
The range hood joins the large venting tube above the cupboards.
The tube runs around the lounge room through this bulkhead and passes above the aircon unit.
And all the vented air comes out here and if you have everything on, including the clothes dryer and range hood, it is quite a force of air.
I'm afraid my green credentials, idealistic as they are, don't run to the exhaust system. We leave the large unit running much of the time when we are home and not in bed. It is nice to pull the
By closing doors, ventilation can be targeted. Say the bathroom is inclined to fog up, then close my bedroom door and the toilet door and extra ventilation happens in the bathroom.
My bedroom being at the opposite end of the apartment to the air con unit, can get quite warm at times in the summer. I close the bathroom, toilet and the two in between bedroom doors, and the inlet in my en-suite pulls cool air into my bedroom. If R is lucky, I might leave his bedroom door open and a little cool air is deflected into his bedroom as it passes by on its way to my bedroom and ensuite. Kind, aren't I.