[beenthere]

It doesn't matter except for aesthetics.

If you don't want to see inside the grille, point them up.

 

[Doitrite]

Thanks, beenthere! I'm tired of looking at the hole in the wall and wanted to complete this weekend while we're snowed in!

 

[americanwood]

Regarding how the louvers should slant for your Supply or Air return on the Wall or Ceiling. There are several factors to consider. If you have an Air Return is on the upper wall I like to slant the louvers upwards so that floor traffic does not view into the duct opening. That is the same with Supply vents as well IF you have adequate air flow and few cold or hot spots in the room from inadequate air flow or distribution. I look at where the supply vents are located and try to set a circulation pattern in the room in order to minimize the hot or cold spots. Therefore, sometimes I recommend to slant the louvers left and right or Up or Down. Wood Vents give you the flexibility to set the angle of "throw", adjust the free air area or set up a good circulation pattern in the room. You can get a free evaluation from www.americanwoodvents.com .