Buildings – ventilation air: Local mean age (NT VVS 019)

  • Report #: NT VVS 019
  • Approved: September 1988
  • Version: 2
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  The scope of this NORDTEST method is to determine the local mean age of air at an arbitrary point in a ventilated space. The theoretical background of the method is described in reference /2/. By knowing the mean age of the air in a point we can: – Determine if the space surrounding the measuring point is well ventilated or not. That is to say, whether the region is “stagnant” or not. – Determine the concentration, at the measuring point, of a dynamically passive contaminant (= follows the air motions) generated at each point in the room with the same and constant release rate. By measuring the mean age of air at several points we can follow the distribution of the ventilation air within the space.