Which type of metallic conduit is recommended for indoor use only?

Electrical Metallic Tubing (EMT) is recommended for indoor use only due to its construction and protective qualities. EMT is a lightweight and thin-walled conduit typically made from galvanized steel or aluminum, which provides a degree of protection against physical damage in indoor settings. It is designed primarily for dry locations, making it unsuitable for outdoor use where exposure to moisture or environmental factors can lead to corrosion or physical integrity issues.

EMT is not rated for direct burial or exposure to hazardous conditions, which is why it's primarily utilized in indoor installations where it can be protected from such risks. It can be easily bent and installed without special tools, making it a popular choice among electricians for routing and protecting electrical wiring in commercial and residential buildings.

In contrast, other conduit types like Intermediate Metallic Conduit (IMC) and rigid non-metallic conduits (such as PVC) have applications that extend beyond interior use, with IMC being suitable for harsher environments. Understanding the specific applications and limitations of each conduit type is important for ensuring compliance with safety regulations and effective installation practices.