How project teams applying combined a ventilation strategy(Mechanical + Natural) should proceed in order to meet the minimum requirements established in ASHRAE 62.1-2007, Table 6-4, for parking garages. ASHRAE 62.1 eliminates exhaustion necessity in cases where at least two sides of the parking garage are at least 50% open to the outside. However, for cases where openings do not meet these requirements ( 30% openings for example), is it possible to reduce the required mechanical ventilation flow rate based on designed opening areas?