BSOH makes available a few web apps 

• CO2sim: a model to simulate carbon dioxide concentrations over time as a function of human occupancy and local and ventilation parameters
• CO2ana: a model to analyze measured carbon dioxide concentrations in time as a function of human occupancy and local parameters (with a view to deriving ventilation parameters)
• BWStat v3: a handy application for processing measurement data according to EN689, the "BOHS/NVvA Sampling Strategy Guidance" and much more...
• BWStat v3.0.2-alpha: an improved version of BWStat v3
  • alpha release for functionality testing
  • treatment of nondetects: corrected mathematical programming mistakes
  • numerical output: removed redundancy; essence retained
  • legend added
• BWStat v3.1.0-beta:
  • beta release for usability testing
  • added new functionality: incorporation of measurement uncertainty
  • improved graphs
  • expanded legend