Section, ground floor, plan, view and details of fireman lift lobby is given in this autocad DWG drawing file. A volume control damper is an essential part of any HVAC system that is to run smoothly and efficiently. A volume control damper works in tandem with the VAV or variable air volume system in a HVAC system, which regulates heating and cooling for the occupants. Thank you for downloading the Autocad DWG drawing file and other CAD program files from our cadbull website.