We're working on a EBOM building, in which the main space is an indoor arena that will hold 4 to 5 national league basketball games a year (with spectators), and all other days of the year, it will serve as a space for training for high performance athletes. 

Because typical operation of the building is with no spectators, the building has installed 2 AHU which supply enough air for the typical users and a small number of spectators.

Is it acceptable that for league games that house a larger number of spectators (which occurs very infrequently, aprroximately 4-5 times a year) the team install temporary fans to supply outdoor air for the spectator area, with enough OA to fulfill ASHRAE´s 62.1-2010 requirements?