A complete portable ventilation system for confined spaces and manholes. The M.E.D.TM allows workers to enter and exit small man-size openings while maintaining continuous ventilation. Without such a device, duct fills the manhole opening, preventing rapid entry and exit. Tightly integrated into the UB-line of confined space ventilation equipment, RAMFAN’s M.E.D.TM is quick to assemble and the new swiveling elbow makes duct alignment easy. Changing its cross-section from circular to elliptical and back to circular minimizes loss and optimizes airflow into a confined space, while providing adequate room for the worker to enter and exit unimpeded. The rugged polyethylene construction endures heavy, negligent use and will last for years. Comprised of three components, the M.E.D.TM, swiveling elbow, and universal mount, the RAMFAN M.E.D.TM system increases safety by maintaining continuous airflow. {C}{C}{C}{C}{C}Ventilate without blocking entry Maintain airflow while working UB-line compatible High impact polyethylene