A duct is an underground or overhead tube used to route and protect electrical conductors as they travel between locations in a commercial or industrial system.
In electrical and low-voltage infrastructure, a duct provides a dedicated pathway that shields conductors from environmental stress, physical impact, and external interference. These pathways support consistent performance by keeping cables organized within a controlled, enclosed route. Ducts are commonly made from materials such as PVC, HDPE, metal, or composite blends, each selected for durability, environmental resistance, or specific jobsite requirements.
Ducts play a key role in environments where electrical conductors must be isolated from moisture, soil, temperature changes, or mechanical loads. Underground ducts protect conductors beneath roadways, parking lots, and landscaped areas, while overhead ducts support elevated runs in facilities such as factories, data centers, distribution hubs, and large commercial buildings. Their primary purpose is to allow conductors to move from point to point safely and consistently without direct exposure to harsh surroundings.
For applications involving communication cables, power conductors, coaxial lines, fiber optic cables, or temperature control wiring, ducts ensure these systems maintain long-term performance within complex layouts. In many commercial and industrial environments, ducts also support expansion by allowing additional conductors to be placed in the same route without altering existing structures.
Duct usage and material requirements are generally guided by organizations such as the NEC and UL, which outline performance, safety, and installation considerations for electrical pathways.
The use of ducts emerged alongside the growth of early electrical and telecommunication networks, where buried and overhead conductors required structured protection. As commercial facilities expanded in size and complexity, duct systems evolved to include stronger materials, smoother internal surfaces, and better sealing properties to support high-density conductor routing.