ETS-Lindgren's EMI/RFI Shielded Waveguide Air Vents allow the free-flow of air into a shielded room for ventilation and prevent electromagnetic interference from entering the room where the waveguides are installed. The electric field, planewave, and microwave shielding effectiveness of the aluminum channels meet all MRI performance requirements. The open cell extruded aluminum channels provide for optimal airflow without clogging as honeycomb style designs are prone to do.

Key Product Information


​​Typical Mounting Methods

Since the vent-to-shield seal is normally the limiting factor in shielding performance, the following waveguide-to-shield seal is required.

Shield Fastening

The aluminum waveguides come with a welded perimeter flange with countersunk mounting holes 3" on center to screw the waveguide to the RF shield wall or ceiling. The flange is bronze arc sprayed to prevent any galvanic reaction between disimilar metals. 

Contact surfaces of the RF shield should be rigid enough to carry even pressure along the flange for maximum shielding performance.
Maximum RF enclosure-to-vent shield performance is achieved by taking the necessary precautions to avoid incompatible metal reactions and by spacing the fasteners at no more than (3 in) on center.

Duct Fastening

Whenever metal ducts are connected to the waveguide air vents on the outside shielded wall or ceiling, a dielectric spacing collar is needed to create a non-conducting break on the duct. The purpose of this break is to keep RF currents on the surface of metal ducts from transferring to the shield wall and lowering shielding effectiveness. The dielectric break may take the form of a rubber or canvas boot, a wooden spacing collar, or other dielectric medium.

Minimum Resistance to Air Flow

The aluminum tube design combines the highest shielding performance with the lowest resistance to air flow. Tube geometry allows the maximum amount of open space while uniformity and depth of the tubes reduces air turbulence.​ 


Key Features


  • Available in a variety of dimensions to match duct sizes 
  • Can be fastened to all RF shielding type designs 
  • Extruded aluminum for Superior RF Performance and Corrosion Resistance 
  • Minimal Air Flow Resistance and Pressure Drop 
  • Continuous welded for seamless RF performance
  • Bronze arc sprayed flange for mounting to all RF shield types

Literature and Videos


Date Last Updated: Thursday, October 24, 2019
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