These design considerations collectively employ a systems approach to solving the problem, including the use of statically conductive air ducts and a properly grounded, electrical power source.
Air ducts normally used for ventilating a nonhazardous confined space are fabricated from material such as a vinyl impregnated polyester that does not conduct a static charge buildup. Air ducts used for ventilating a hazardous location type confined space are fabricated from a special manufacturing process. The materials are designed to conduct and dissipate the electrical charges created by the movement of air during the ventilation process. Without this added conductive property, air movement would create static electrical charges on the duct surface that have no method of dissipation. Just touching the duct could allow the charge to dissipate in the form of a random spark. This could be the ignition source of an explosion if the blower is being operated in the appropriate hazardous atmosphere.
However, with the EP8HL blower the statically conductive air duct allows a static electrical charge to be effectively conducted through its length until it is eventually dissipated through the ground wire of the electric power cord. The EP8HL blower is designed so only the statically conductive ducts can be used with it, thereby eliminating the possible use of a standard, non conductive duct in a hazardous atmosphere.