3 way grille or 4 way grill in front of the window

[alex123]

Can someone explain to me when to use 4 way grille and when 3 way? In this particular I case I need to replace old rectangular grille in the ceiling tile right above the window to the new 8 by 8 one, not sure what kind
Thanks

[dash]

Norally;

4 way is centered in the room,3 way is on/near a wall ,with one throw into the room,and the other two along the wall in opposite directions.

[alex123]

Norally;

4 way is centered in the room,3 way is on/near a wall ,with one throw into the room,and the other two along the wall in opposite directions.

Thanks,

Is one way better then other or just depends on location of the outlet? In other words if 3 way moved away from the window and changed into 4 way would result be the same ?

[dash]

IMHO,it depends on your climate.

4way centered works well in Florida,with most of the summer heat gain is at the ceiling,in a colder climate the 3 way puts two thirds of the air along the outside walls in the winter,where most of the hest loss is.

[classicrock4you]

The true purpose of ductwork is to "WASH" the window with a thermal barrier and keep the outdoor temperature outdoors. Any other air is wasted.

[mbarson]

The true purpose of ductwork is to "WASH" the window with a thermal barrier and keep the outdoor temperature outdoors. Any other air is wasted.

Could you please explain this in greater detail.