Calculate case airflow, air changes and the temperature rise it permits.
Airflow removes heat in proportion to mass flow, so doubling airflow halves the temperature rise. Intake filters cost far more airflow than exhaust paths, which is why intake and exhaust are derated differently. Positive pressure means all incoming air passes a filter, which keeps the interior clean and is usually worth a small airflow penalty.
Case Fan Airflow
Temperature rise = heat ÷ (mass flow × specific heat of air)
Temperature rise = heat ÷ (mass flow × specific heat of air) Airflow removes heat in proportion to mass flow, so doubling airflow halves the temperature rise. Intake filters cost far more airflow than exhaust paths, which is why intake and exhaust are derated differently.
Positive pressure means all incoming air passes a filter, which keeps the interior clean and is usually worth a small airflow penalty.
This calculator takes 5 inputs: Intake fans, Exhaust fans, Airflow per fan, Loss from filters and restriction, System heat output. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.