What type of flex connectors from electric dryer vents is prohibited from being concealed?

The prohibition against concealing single-piece flexible connectors in electric dryer vents is rooted in safety and performance considerations. Single-piece connectors are designed for ease of installation and can allow for proper airflow; however, if they are concealed, it can lead to several issues such as increased risk of trapped lint. Trapped lint can create fire hazards since dryers produce heat and lint is highly flammable. Additionally, if any maintenance or inspection is needed, a concealed connection may complicate access, preventing timely intervention to address any potential problems.

Flexible connectors with insulation, multiple piece connectors, and non-metallic connectors may still have different considerations regarding safety and installation guidelines, but the specific rule against concealing single-piece connectors highlights a focus on preventing hazards associated with lint accumulation and ensuring that ductwork is accessible for inspection and maintenance.