Doors that open onto corridors that are used for a means of egress may be required to have a smoke and draft control rating. Smoke and draft control assemblies are tested for both air leakage and fire resistance. The assembly is tested to determine how much air leaks around the door. The assembly is tested for air leakage with air that is at room temperature and air that has been heated to 400°F. The amount of air leakage must be below the standards that are set forth in the building code and/or NFPA 105. An identical assembly is also subjected to a fire test. The unit must at least pass a 20- minute-without-hose-stream fire test to be qualified as a smoke and draft control assembly.