Potential for natural ventilation in urban context : an assessment method

The natural ventilation potential (NVP) is the possibility, or probability, to ensure anacceptable indoor air quality by natural ventilation only. A passive cooling potential (PCP)can also be defined, as the possibility to ensure an acceptable indoor thermal comfort usingnatural ventilation. Ensuring an acceptable indoor air quality, or cooling down the buildingstructure by natural ventilation hangs on many conditions depending on the site (outdoor airquality, outdoor air temperature and moisture, outdoor noise, local winds or global wind andurban structure, etc.) or on the building (indoor pollutant sources, indoor heat sources andstored heat, indoor air quality requirements, position and size of ventilation openings, indoortemperature, orientation of building, internal air path distribution, etc.)The NVP cannot therefore be expressed as a single number. It is a multiple attribute variable,i.e. a list of quantitative and qualitative characteristics of the site or the building, based onavailable input data. It is nevertheless possible to decide, on the basis of these characteristicscombined with the requirements, if a given building or a room in a building is likely to bewell enough ventilated or not using natural ventilation. No detailed modeling is required forthis assessment, which is based on existing experience.The contribution presents the method developed to assess the NVP and PCP, and to representit using geographically referenced information.