A Lev door or convection door is really an interior flooring-to-ceiling (entire height) door, consisting of a regular doorway leaf and an upper leaf in place of the standard header wall. The leaves may or may not be divided by a transom. The doorways empower efficient convection of heat air. https://d06772.wikiusnews.com/1596197/5_simple_techniques_for_destination_delivery_and_unpacking_kuwait