ASHRAE HVAC Apps Handbook Equation, Table 2, and Walls

I have a laundry room in a building which has no interior doors to other inhabited interior spaces, only an exterior door and exterior windows. A reviewer referred me to an equation in Section 53.5 of the 2011 ASHRAE HVAC Applications Handbook. I have the 2015 Handbook here, and an equation there in Section 53.7, adjusted for units, has the differential pressure in Pascals at the square of CFM of airflow divided by 27552 times the square of the leakage area in SF. To achieve 5 Pa, this means 371.16 CFM per square foot of leakage area. Table 2 lists exterior, stairwell and elevator shaft walls, but not interior walls to other types of spaces. Should I use the exterior wall numbers for interior walls not adjacent to stairwells or elevator shafts? And should I use the loose, average or tight numbers in Table 2?