access door clear opening: verify the hand and tool can actually reach fire/smoke dampers, rated assemblies & access duct access door clear opening reach tool service inspection check the true clear opening, door swing or panel removal, nearby obstructions, insulation, and the actual service task before locating the door. a door can technically exist and still be useless when the technician cannot reach the device or operate a tool. device manufacturer instructions, approved details, project access requirements, commissioning/maintenance needs will this access door give a real clear opening to inspect, reset, clean, or service the device after all finishes are installed?