Thought Leadership

FloEFD HVAC Module – Taking Built Environment CFD Simulation to the Next Level

By Robin Bornoff

The recently released FloEFD HVAC Module brings a raft of features specifically tailored to enable FloEFD to be used for built environment simulations. FloEFD  has an unrivalled pedigree in the automating of advance CFD (computational fluid dynamics) techniques and capabilities, allowing the user to focus on application and not numerics. This democratisation of CFD brings the ability to simulate the true 3D physics of air flow, contaminant dispersion, thermal comfort and thermal efficiency of the built environment to a much broader range of designers.

Occupant thermal comfort and the management of indoor air quality are key green building design challenges. Standards such as  ASHRAE Standard 55-2004 (covering thermal comfort in a space) and ASHRAE Standard 62.1-2007 (covering ventilation for acceptable indoor air quality (IAQ)) can be addressed using CFD simulation. FloEFD’s HVAC Module provides the ability to simulate the following metrics, allowing spaces to be designed so as to assure acceptable thermal comfort behaviour and maximised IAQ levels:


  • Predicted Mean Vote (PMV)
  • Predicted Percent Dissatisfied (PPD)
  • Operative (comfort) Temperature
  • Draft Temperature
  • Air Diffusion Performance Index (ADPI)
  • Contaminant Removal Effectiveness (CRE)
  • Local Air Quality Index (LAQI)
  • Flow Angle

Radiative heat transfer is central to the thermal efficiency of any given built environment. Whether it is short wave solar loading or the effects of infrared radiative exchange, FloEFD’s advanced radiation capabilities allow for the modeling of:


  • Semi-transparent solids (Radiation absorption in solids)
  • Wavelength dependency
  • Spectrum definition
  • Specularity of surfaces
  • Refractive index


From atria with curved glass facades to car parks with jet fans and from hospital isolation rooms to pharmaceutical clean rooms; FloEFD’s HVAC Module and FloVENT provide the full spectrum of CFD solutions for the needs of built environment design.


31st January 2011, Ross-on-Wye

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This article first appeared on the Siemens Digital Industries Software blog at