You can use the arrow-shaped ( 
) Rotate grip to rotate HVAC in-line parts, duct fittings, and takeoffs 180 or 90 degrees in the direction indicated by the grip.
Rotating a damper 180 degrees in plan view
In isometric views, if the part, fitting, or takeoff has round connectors on opposite ends, you can also use the diamond-shaped ( 
) Rotate grip to rotate the object around its centerline to any angle you specify.
Rotating a damper in an isometric view
AutoCAD MEP 2024 toolset displays Rotate grips on all HVAC in-line parts, fittings, and takeoffs with connectors on opposite ends. However, when necessary to preserve the connectivity of duct runs, the software limits the available rotation options or hides the grips. For example, in the following illustration, you can rotate the wye fitting on the left in several ways, but you cannot rotate the wye fitting on the right due to the connected branch.
Wye fitting with Rotate grips and another without
When you rotate a part, fitting, or takeoff that is connected to other objects, the software adjusts the connected objects to maintain connectivity. For example, the software might make minor adjustments to the lengths of connected duct segments after you have flipped a fitting. If it cannot adjust the objects, it disconnects them.