There is a simple equation that can be applied to obtain the approximate airflow required for a given application, however it is impossible to account for all variables so actual requirements can only be determined through application testing.
The equation is “Q= 0.05W/Tc m3/min.”
Q: Required airflow
W: Internal heat dissipation in Watts
Tc: Temperature difference at enclosure inlet ºC
For example, Tc is 8ºC and internal heat dissipation is 300W, then required airflow is (0.05×300)/8=1.875 m3/min.