Air Filters Also Trap EMI

A line of cleanable, dual EMI Honeycomb air filters are designed for rack-mounted cooling units for large cabinet openings that develop potentially disruptive EMI/RFI noise. Previously, honeycomb or expensive perforated metal panels were specified separately and permanently mounted to shield moderate levels of EMI. The new removable air filters provide low-cost air filtration and EMI shielding in a single, compact assembly. The filters have a stainless-steel mesh that is bonded to the aluminum frame with a conductive silver/copper adhesive caulk. In addition, an EMI shielding gasket is installed around the frame perimeter to assure full conductivity of the frame to the equipment. Along with minimal airflow impedance, the structure cells reflect and absorb EMI noise. Attenuation is more than 60 dB over a frequency range of 10 kHz to 1 GHz.