Direction of Louvre vent

[Jupiter01]

I have a air vent in a solid wall. It's approximately 1.6m up the wall.
With this type of vent, should the vents be facing upwards or downwards please? Also, what's the rationale behind the direction of the airflow.

Thanks in advance.

 

[noseall]

With this type of vent, should the vents be facing upwards or downwards please?

Either, it doesn't matter. Most people who fit them outdoors put them with the louvres down-bank, so that the rain runs off rather than in.

 

[Jupiter01]

I am fitting this internally in the bedroom

 

[JohnD]

If they face downward, it will be easier to dust.

 

[^woody^]

At high level, vents facing upwards avoids down draughts, and you don't see the vent gaps so looks better. It's the opposite at low level