I don't know how to interpret the following section of ASHRAE 62.1-2010:

"6.4.1.2. Double side openings. For spaces with operable openings on two opposite sides of the space, the maximum distance from the operable openings is 5H, where H is the ceiling height"

Option 1-the distance between the two walls is 5H, (i.e. the air travels a distance of 5H)

Option 2-the ventilated area is 5H from each opposite wall (i.e. the distance between the two walls can be a maximum of 10H)

Thank you,