Does the heat dissipation hole of the AI computing module in an industrial AI edge gateway affect the EMC shielding effectiveness?

Directly opening the heat dissipation holes of the AI computing module in the shielding housing of an industrial AI edge gateway will significantly degrade the shielding effectiveness. Improper design can reduce the 1GHz shielding effectiveness from 40dB to 15dB. Improvement methods:

Method 1: Use a small round hole array with a hole diameter ≤3mm and a hole spacing ≥5mm, and the shielding effectiveness will recover to 30dB.

Method 2: Use a waveguide ventilation plate with hexagonal honeycomb holes, a side length of 2mm, and a hole depth of 5mm, and the shielding effectiveness will be >60dB.

Method 3: Apply conductive wire mesh to the inside of the heat dissipation holes and reliably ground it to the housing. Audiotech provides customized ventilation waveguide plates.

In a test, after replacing the 8mm perforated mesh with a 3mm round hole array, the 1.2GHz radiated emission of a gateway decreased by 12dB.