What type of cable must be used to run Ethernet cables in a false ceiling area with air conditioning and heating ducts?

In environments with air conditioning and heating ducts, such as false ceiling areas, it's essential to use plenum-rated cable. These cables are designed for use in spaces that can promote the spread of fire and are specifically constructed to meet stringent fire safety regulations. Plenum-rated cables have a special insulation that reduces the amount of smoke and toxic gases released in case of a fire, making them safer for use in return air pathways where air circulation occurs.

Using plenum-rated cables in these environments ensures that, should a fire occur, the risk to occupants and the potential for further damage to the building is minimized. Regular, standard Ethernet cables or non-plenum rated cables do not have these safety features and could pose serious hazards in a plenum space. Shielded cable, while useful for reducing electromagnetic interference, does not address fire safety requirements specific to plenum areas. Thus, choosing plenum-rated cable is the correct decision for this scenario.