One thing that you guys might be overlooking is the size of the mesh of the screen. A mesh size of 1/16 inch will probably not cause any degradation in airflow-OTOH a mesh size of 1/32 or smaller would. I have seen some tea strainers tha use a very small mesh size (between 1/64 and 1/32 inch). Only sure way is to test it with and without. Scott