LG MULTI V ARNU07GTUA4 Engineering Product Data Book page 365

Indoor unit
11. Installation
3. Installation of intake air duct
Min. 2m
1/30 Slope
Inlet Hood
Inlet Hood should be installed such that no water enter inside the unit
Intake Air Duct
The Intake Air Duct must have down-slope about 1/30.
The length of Intake Air Duct should be longer than 2m.
Fresh Air Intake Unit
If wired remote controller is not connected, it will display strange value to the room temperature
Exhaust Fan
Fresh Air Intake Unit will make room the positive pressure.
Exhaust fan should be installed to maintain the room pressure.
Door
It would be possible to raise in the room air pressure because of Fresh Air Intake Unit.
In that case, the door could hurt someone in front of door.
So be careful of the positive pressure to design the door.
18 _
Fresh Air Intake Unit
Outlet Air
Exhaust air
Inlet Hood
Intake Air Duct
Fresh Air Intake Unit
Exhaust Fan
Door