What type of cables should be avoided in a plenum?

In a plenum space, which is typically used for air circulation in heating and cooling systems, it is essential to ensure that all cables used are rated for such environments due to fire safety concerns. Non-plenum rated cables do not meet the necessary flame spread and smoke developed standards required for use in plenum spaces. If these cables were to catch fire, they could produce harmful smoke and potentially contribute to rapid flame spread, posing significant risks to life and property.

Low-voltage cables, coaxial cables, and fiber optic cables can all be designed to be plenum-rated, thus being suitable for use in such environments. Plenum-rated cables are constructed with materials that have lower flammability to minimize risks in case of fire. Therefore, it is critical to avoid using non-plenum rated cables in a plenum to maintain safety standards and comply with building codes.