Faraday Room Design Overview

A Faraday room (also called an RF-shielded enclosure) is a controlled space designed to prevent electromagnetic fields (especially radio frequency / RF) from entering or exiting. The effectiveness depends on the shielding envelope and all systems (lights, power, HVAC, etc.) being integrated without leaks.

The primary design elements include copper-lined walls, fiber optic lighting, filtered power line penetrations, shielded HVAC waveguide vents, and layout rules for proximity to EMI sources (transformers, generators, etc.). Each component must be carefully detailed to maintain continuous shielding. 

Lined Walls and Envelope

Walls, floor, and ceiling of the room must be continuously lined with copper sheet or mesh to form a conductive barrier. All seams, joints, and overlaps must be electrically bonded (via solder, conductive tape, or welding). Any gap will degrade shielding performance. Penetrations (cables, pipes, etc.) must use RF gaskets to preserve the envelope.

Recommended products:

• Copper Foil Tape with Conductive Adhesive: 3M 1181 EMI Shielding Tape

• Copper Mesh Shielding Rolls: TMI Copper Shielding Mesh

• RF Shielding Panels: ETS-Lindgren RF Shielded Enclosures

RF Shielded Door Construction

The door must be specifically designed as an RF-shielded door, not a conventional fire- or acoustic-rated door. It includes metallic surfaces (steel or copper-clad) and internal RF gasketing systems to maintain contact with the door frame. Shielded doors should be tested and rated for shielding effectiveness per IEEE-299. Most systems use a knife-edge + gasket design, or compression-contact finger stock for uniform sealing. 

Example products:

• ETS-Lindgren RF Shielded Doors

• Holland Shielding Systems – RF Shielded Doors

  
  

EMI Gaskets & Fingerstock

The seal between door and frame is usually provided by EMI gaskets or beryllium copper fingerstock that ensures metal-to-metal contact under compression. These gaskets must be electrically conductive and maintain consistent pressure to prevent leakage.

Types of seals include:

• Beryllium copper fingerstock (very high durability and contact reliability)

• Conductive fabric-over-foam

• Monel mesh or copper spring fingers

Seals must be tested periodically and replaced if worn or corroded.

Examples:

• Spira EMI Gaskets

• Leader Tech Fingerstock & Conductive Gaskets

  
  

Automatic Latching and Pressure Systems

For security and consistency, shielded doors often feature automatic compressions mechanisms, such as:

• Cam-lift hinges

• Compression levers or motorized latching systems

These ensure that uniform pressure is applied across the full perimeter of the door frame every time the door is closed.

Lighting – Fiber Optic Systems

Conventional light fixtures have ballasts and drivers which emit electromagnetic fields. Instead, use fiber optic lighting, where the light source (the “light engine”) is positioned outside the shield, and light is brought in via nonconductive fiber bundles. The fiber passes through sealed feedthroughs (waveguides or gaskets). This prevents EMI intrusion through lighting circuits.

Recommended systems:

• Remote Source Fiber Optic Lighting by Lumencor

• Fiberstars Fiber Optic Systems

  
  

Power and Data Lines Filtering & Penetrations

Power and data lines entering the chamber must go through EMI / RFI filter panels to suppress high-frequency signals. Each cable must be shielded and bonded at the entrance. A shielded power entry panel (outside the room) is often used, with all filters connected to the shielding envelope. Where needed, use isolation transformers or additional filtering stages.

Recommended filters:

• Corcom Power Line Filters – TE Connectivity

• TS-Lindgren Filter Panels

  
  

HVAC & Waveguide ventilation

The room will need ventilation and cooling, but HVAC ducts are potential RF leakage paths. Use honeycomb waveguide vents or waveguide air passages. These allow airflow, but attenuate electromagnetic waves. Ducts should be short, straight, and isolated; transitions to the shield wall should use EMI gaskets. Fire dampers must also be shielded or equipped with RF-sealed shutters.

Recommended waveguides:

• Leader Tech Honeycomb Vents

• ETS-Lindgren Waveguide Vents

Proximity to Transformers / Generators / Large EMI Sources

Large electrical equipment (transformers, generators, etc.) emit stray magnetic and electric fields that can penetrate shielding if too close. To reduce risk, keep these devices at a distance. Not a requirement; however, as a guideline, one might propose 25 feet of separation. If closer placement is unavoidable, additional magnetic shielding (high permeability materials) or active cancellation may be required. Further determination of additional shielding can be performed on site.