HG_Flow is a CFD software designed for persons and products protection in potentially contaminated areas. HG-Flow is integrating the acquired expertise in HVAC controlled environments. Airflows are visualized and diffused aerosols are quantified in compatible calculation times for a routine use. For a better precision of the solutions developed by HG_Flow, environments including equipment and people present in the premises may be scanned with a 3D laser-scanner, providing accurate and true details as small as one millimeter.