Put ducting in the passive intake holes.Either use 45° bends as a light trap,or paint the inside of the ducting black.
Passive intakes need two be twice the area of your exhaust.
Example...
A 4" exhaust has an area of 12.6" square inches so you'd want either two passive intakes that each have an area if 12.6" square inches or one passive intake that has an area of 25.1 square inches.
You did not read Ventilation 101...otherwise you wouldn't be asking.
GO READ VENTILATION 101!
Passive intakes need two be twice the area of your exhaust.
Example...
A 4" exhaust has an area of 12.6" square inches so you'd want either two passive intakes that each have an area if 12.6" square inches or one passive intake that has an area of 25.1 square inches.
You did not read Ventilation 101...otherwise you wouldn't be asking.
GO READ VENTILATION 101!