How can industrial servo ventilation ports also provide shielding and heat dissipation?

Server rack ventilation openings must balance EMC shielding and heat dissipation requirements. Etymotics Solutions utilizes honeycomb air vents. These vents consist of an array of hexagonal metal conduits, offering low airflow resistance. However, for electromagnetic waves, when the conduit aperture diameter d < λ/2 (λ being the wavelength of the highest shielding frequency), electromagnetic wave attenuation is significant. For example, for 1GHz (λ=30cm), the aperture diameter d should be <1.5cm. The waveguide frame should be connected to the rack wall with low impedance via conductive pads or soldering. For less demanding applications, perforated metal plates (perforated arrays) can be used, but with lower shielding effectiveness. The required ventilation area must be calculated during the design phase to select an appropriately sized waveguide. Real-world testing shows that a well-designed honeycomb air vent provides sufficient airflow while offering 40-70dB of shielding effectiveness between 30MHz and 1GHz, ensuring timely heat dissipation within the rack without sacrificing EMC performance.