JHC offers a comprehensive range of military and commercial grade vents & filters for any application requiring shielding airflow across an enclosure aperture.
SHIELD-CELL™ & OMNI-CELL™
Shielded Vent Panels
SHIELD-CELL and OMNI-CELL EMI Shielded Ventilating Panels. Ready to-install SHIELD CELL and OMNI CELL panels provide maximum EMI shielding with minimum pressure drop (air flow resistance) for ventilating air. All styles are composed of metal honeycomb shielding panels in EMI gasketed frames of like material. Panels are ready-to mount, in such a manner that the frame gasketing is compressed firmly against the shielded housing to maximize shielding performance. Standard framing for all panel designs includes both an EMI shielding gasket and a seal, from a combination of monel knitted wire mesh and sponge neoprene. Panels larger than 12 x 24 in. (305 x 610mm) are equipped with cross braces.
CHO-CELL panels are Parker Chomerics very high performance shielded honeycomb air vents, especially designed for high frequency environments and to meet TEMPEST specifications. They provide greater than 90 dB attenuation between 200 MHz and 10 GHz. Shielding is typically 30 dB better than conventional panels, achieved by unique design features, which include a CHOSEAL mounting gasket. CHO-CELL vents are free of polarization effects, provide low air resistance, and are lightweight. They are offered in custom configurations, with thru-hole mounting.
With their exclusive designs (patent pending and manufacturing process, Parker Chomerics STREAMSHIELD vent panels have been developed as a high performance, economical solution to the EMI and airflow issues in information technology and telecommunications applications. Increased electromagnetic radiation and heat generation, together with intensified regulatory requirements for emissions suppression, necessitate a more sophisticated solution than simple perforations or louvers in electronic enclosures.
Parker Chomerics steel honeycomb ventilation panels are designed for maximum H-field shielding effectiveness. They are especially suited for use in military enclosures, communications shelters and shielded rooms, and should be of interest to designers of EMPhardened and TEMPEST equipment. In applications where environmental concerns are critical, brass honeycomb shielded vents are recommended. They provide optimum EMI shielding performance plus corrosion resistance.
Ready-to-install SHIELDSCREEN filters incorporate highly effective, integral EMI frame gasketing of monel with an optional neoprene sponge weather seal. Filtering is provided by several layers of woven wire mesh behind a retaining grille. The mesh layers are nested in “hills and valleys” of decreasing height to separate layers and increase dust holding capacity (see Figures 1 and 2). The mesh filter may be used dry, or wet with viscous oil coating, which improves adhesion of dust particles to the filtering material. SHIELDSCREEN frames are of the same EMI gasketed, extruded aluminum construction as SHIELD CELL aluminum honeycomb panels. Because they are complete assemblies, removal for periodic cleaning is simple. Dry filters are cleaned by vacuuming from the intake side (which can be accomplished in place), or in detergent solution. Oil impregnated filters require removal and cleaning in detergent solution. Re-oiling is required after cleaning with detergent. The standard, inexpensive SHIELDSCREEN design 61- 118 (Figure 1) requires the least space and includes installed fasteners. Typical alternative styles are shown in Figure 2, but more than a dozen others are available
Ready to install 360° panels provide maximum EMI shielding with minimum pressure drop (air flow resistance) for ventilating air. In certain applications, round vents offer fit and/or cosmetic advantages. The following styles: Cho-Cell™, ShieldScreen®, Shield Cell®, Omni Cell®, and Stainless Steel are available in round design. Round panels will also be available in brass and steel but only using the “C” channel extrusions (61-118-M, 61- 125-M, 1-123-M, 61-195-M, 61-311-M & 61-140-M). Typical framing for all panel designs, except Cho-Cell™ and ShieldScreen®, includes both an EMI shielding gasket and an environmental gasket, Parker Chomerics COMBO® Gasket (see figure 1). Shielding gaskets can be designed to have the environmental gasket on either the inside diameter (ID) or outside diameter (OD) of the panels. Round panels are made of spun metal or circular tubing (6061-T6 or 6061-T1 per QQ-A- 200/8 or QQ-A-250/11). All styles are also available with holes or rivnuts per customer’s request. Panels will be available from an OD as small as 2.0” up to a maximum OD of 15.0”.