A Lev doorway or convection doorway is definitely an inner flooring-to-ceiling (whole top) door, consisting of a normal doorway leaf and an upper leaf rather than the same old header wall. The leaves may or may not be divided by a transom. The doors empower powerful convection of heat air. https://d37158.wikilowdown.com/6972451/the_fact_about_freight_and_cargo_services_kuwait_that_no_one_is_suggesting