Ventilation collection:
https://3dsky.org/collection/shared/5333943 

CORONA + VRAY (2013)
FBX CORONA + VRAY (2009)

Ventilation system for ceilings.
The kit includes an assembled ceiling consisting of several ready-made modules and a set of individual elements for assembling various options.
The model has a system of cable trays, air conditioners and a fire protection system.
The set uses 6 types of materials that can be applied to any element.
Most of the details are edited using Edit Poly and adjusted to the required dimensions.
The diameters of the circular ducts are 200 , 315 , 400 , 500 , 600 mm.

Other sets :
https://3dsky.org/users/solomon5555/models