Primary air inlet, location

Using already mentioned (on the rocket mass forum) the size of primary inlet.  For a 7" sized riser, we have the option of where to place on the door.  

Has it been found, that low, med or high placement works best. This a standard batch box, 7" riser,  with bottom P channel

Shown would be a door with ceramic glass behind the oval cut out, with primary below it.

thanks in advance

Hi Scott;
Low is best