Which plan shows visible parts of a HVAC system, such as ducting and essential equipment?

• A. Plumbing plan
• B. Mechanical plan
• C. Floor plans
• D. Fire protection plan

Answer: (B)

Drawing a building’s plans by subsystem helps crews know exactly where to install and connect different systems. The part of the drawings that shows the physical, viewable elements of the HVAC system—ductwork, air-handling units, fans, dampers, diffusers, and associated equipment—is the mechanical plan. It focuses on the layout and placement of ducts and key components, so installers can see how air travels through the building and where equipment sits, how it’s fed, and how it connects to controls and electrical systems.

Other plans serve different purposes. A plumbing plan concentrates on water supply and drainage piping and fixtures. Floor plans show walls, rooms, doors, and general spatial layout without detailing HVAC ductwork. A fire protection plan depicts sprinkler and detection systems, not the duct routes or HVAC equipment. So the plan that shows the visible parts of an HVAC system is the mechanical plan.