IMC 2012 403.3.1.1 
BREATHING ZONE OUTDOOR AIRFLOW.
Table 403.3

Auditorium S.F. = 			2103 s.f.
Occupiable Space		*	 75%.
Auditorium				1577 s.f.

Based on Occcupancy
Education Auditoriums

Rp = 5
Pz = 150 * 1577 / 1000 = 236
Ra = 0.06
Az = 1577

Vbz  = (Rp Pz) + (Ra As)

 (5 * 236) + (.06 * 1577)
=1275 cfm fresh air

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Corridor S.F.			289 s.f.

Based on Occupancy

Rp = -
Pz = -
Ra = 0.06
Az = 289

bz  = (Rp Pz) + (Ra As)

 (- * -) + (.06 * 289)
=17 cfm fresh air

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Total Fresh Air = 1275 + 17 = 1292 cfm