Which type of cable would you use for connections within a building's heating and air conditioning system?

Plenum-rated cables are specifically designed for use in spaces that facilitate air circulation, such as the areas above ceiling tiles or below raised floors where heating, ventilation, and air conditioning systems operate. These cables have a fire-resistant jacket that emits lower amounts of toxic smoke when burned, making them suitable for environments where air circulation is critical to a building's heating and air conditioning systems. In many codes and regulations, the use of plenum-rated cables is required for any cabling that runs through such spaces to minimize fire hazards and improve safety.

Other types of cables do not meet the stringent requirements for safety and fire resistance in these applications. For example, direct bury cables are intended for underground use and are not suitable for indoor air-handling spaces. Cat 7 cables, while high-performance network cables, are not specifically rated for plenum spaces and can pose safety risks if used improperly in such environments. Non-plenum rated cables lack the necessary fire-resistant properties, further underscoring why plenum-rated cables are the appropriate choice for HVAC systems in buildings.