Step 5. Select Your Filter Fan

In this final step, we bring together the results of free airflow (step 3) and system impedance (step 4), using the filter fan performance charts. Applying the example, we need to select a motorized impeller that delivers a minimum of 360 CFM (611 M³/Hr.).

Identify alternative filter fan models with free airflow ratings that are greater than the step 3 outcome of 360 CFM (611 M³/Hr.) to compensate for airflow losses created by static pressure in the system. A judgmental system impedance curve is overlaid onto the performance charts of each of the optional filter fans, and then the model with the CFM or M³/Hr. closest to the target airflow is selected.

In the performance curve shown here, 571 CFM is commonly the largest filter fan in the electronics cooling industry. Based on the estimated electronic component impedance overlaid by our imaginary engineer, it should deliver the cooling performance required by the system.