HBI Haerter - Consulting Engineers Your partner for ventilation, aerodynamics and safety of tunnels HBI Haerter AG (CH) and HBI Haerter GmbH (DE) are firms of consulting engineers. Our services: Design, planning and execution of projects in the field of tunnel ventilation Pollution dispersion analysis Risk analysis and safety Aerodynamics and thermodynamics Our objects: Road tunnels Railway tunnels and underground stations Underground systems Supply tunnels, underground sites Provided project phases: Feasibility and concept studies Preliminary and in-depth studies Implementation planning Construction supervision and acceptance Refurbishment and optimisation during the operating phase Measurements