12. Shielding Air Vent Materials

The various types of materials that are presently used to supply airflow and shielding to enclosures, cabinets, and electronic system are presented. These materials include conductive screening, perforated metal, and honeycomb panels. The relative level of airflow and shielding by each of these materials is thoroughly presented. Honeycomb materials provide excellent airflow properties where the shielding can vary between 30 dB and 140 dB. The level of shielding is principally a function of the method used in tying the individual foils together. The highest level of shielding is provided by brass and iron soldered together where the shielding can exceed 140 dB. Stainless steel panels are formed using stainless steel foils spot welded together. A single spot weld will provide approximately 60 dB of shielding. The shielding associated with aluminum can vary between 30 dB and 120 dB where the variables are thoroughly documented.