Welcome back to the CAD Teacher VDCI video course content for the BIM 321 course, Introduction to Revit MEP. In our previous session, we successfully positioned our Air Handler Unit on the roof. Now we'll focus on routing these ducts down through the shaft to create seamless system integration—a critical step in establishing efficient MEP coordination that modern BIM workflows demand.

Let's begin by adjusting our section view to clearly visualize both the shaft and our two existing ducts. I'll pull back the section view and reduce the visible elements to focus specifically on the ductwork we're routing downward. This targeted approach helps maintain clarity during complex routing operations and prevents visual clutter that can lead to modeling errors.

For the first duct run, I'll initiate a new duct segment and route it straight down to our target elevation, then offset it slightly for proper alignment. This positioning strategy ensures we maintain adequate clearance while optimizing system performance. The same methodology applies to our second duct—route vertically, then adjust horizontally for optimal positioning within the shaft constraints.

Before proceeding further, it's essential to verify our ductwork placement on the first floor plan. This quality control step ensures our ducts maintain proper clearance from shaft walls and align correctly with existing system components—a practice that prevents costly field conflicts and maintains code compliance.

Switching to our first floor ceiling plan reveals some alignment issues that require attention. I'll adjust both duct segments by sliding them outward to achieve proper clearance, then use Revit's align command (AL) to precisely position the duct edge with the existing ductwork. This level of precision is crucial for maintaining system integrity and ensuring accurate material takeoffs.

With alignment complete, we can now connect these segments using the trim command. If the trim operation encounters resistance, return to the section view and use the align command to synchronize the duct elevations—this troubleshooting approach resolves most connection issues. Execute the trim command (TR) on both connection points to complete the system integration.

Moving to our second-floor ceiling plan, we'll encounter a slightly different alignment scenario. Here, I'm targeting the duct centerline rather than the edge—a technique that's particularly effective when working with symmetrical layouts or when maintaining consistent spacing is critical.

If standard alignment tools don't achieve the precision you need, consider using a detail line (DL) as a reference guide. Draw from the midpoint of your reference element to create a temporary alignment aid. However, in most cases, centerline-based alignment provides sufficient accuracy for professional-grade modeling.

Complete the connections by dragging each duct segment until it reaches the target centerline. Revit's intelligent connection system will automatically generate the joint when segments are properly aligned—one of the software's most valuable time-saving features for MEP professionals.

Let's review our completed work in section view to verify proper system flow and connectivity. The integrated mechanical system now provides a clear pathway from our Air Handler Unit through the building's distribution network—exactly what we need for effective MEP coordination and system commissioning.

Our 3D view reveals the professional-quality mechanical system we've created. This foundational ductwork demonstrates the power of systematic BIM modeling and establishes the framework for more complex MEP integrations. As we move forward in 2026's increasingly collaborative construction environment, this level of model precision becomes essential for successful project delivery.

This concludes the mechanical systems portion of our course. I encourage you to experiment with additional duct routing scenarios and explore different connection strategies. We may revisit this model later to add an exhaust system for the restroom facilities—a straightforward application of the principles we've covered today. Next, we'll transition to plumbing systems, where these same coordination principles will prove equally valuable. See you in the next session.