Is it permissible for ENT to be used in all plenum applications?

In plenum applications, particularly in building environments, it is crucial to understand the specific codes and standards governing the materials that can be used due to fire safety and air quality concerns. Using ENT (Electrical Nonmetallic Tubing) in plenum spaces is not permitted because it does not meet the fire-resistance requirements outlined in the National Electrical Code (NEC). Plenums often serve as pathways for airflow in HVAC systems, and materials used in these spaces must have specific flammability ratings to prevent the spread of fire and harmful smoke in case of an incident.

Therefore, the prohibition of ENT from being used in these applications is based on the need to ensure safety and compliance with established building codes, highlighting the critical importance of adhering to regulations in the installation and use of electrical materials in different environments. The standards set by authorities are aimed at minimizing risks associated with electrical installations, especially in areas where they share space with air circulation systems.