TinnerFlow™2nd YearBlueprint ReadingYELLOW · Check First
Duct Drop: Typically noted on the floor plan with a square box containing a diagonal 'X' pattern or a solid shaded black pattern accompanied by the abbreviation DN (Down). * Duct Rise: Typically noted with an open square box containing a central target dot or a single clean slash line accompanied by the abbreviation UP.
Duct Drop: Typically noted on the floor plan with a square box containing a diagonal 'X' pattern or a solid shaded black pattern accompanied by the abbreviation DN (Down). * Duct Rise: Typically noted with an open square box containing a central target dot or a single clean slash line accompanied by the abbreviation UP.
Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.