PFT

The PerFluorocarbon Tracer (PFT) method is a low-cost approach commonly used for measuring air exchange in buildings using tracer gases. It is a specific application of the more general Continuous-Injection, Long-Term Sampling (CILTS) method. The technique is widely used but there has been little work on understanding the uncertainties (both precision and bias) associated with its use, particularly given that it is typically deployed by untrained or lightly trained people to minimize experimental costs.

High local concentrations of a pollutant can be the result of high local emission rates of the pollutant orinsufficient ventilation. Using tracer gases to map the ventilation in multi-zone buildings combined withmeasurements of the local pollutant concentration provide the means to discriminate between thesecauses.

This study reports ventilation measurement and occupant questionnaire results from newly built 102 Finnish detached houses. The results show that ventilation units were used constantly and the fan speed setting was changed very seldom. There was as light tendency to use higher speed in the summer than in winter. Ventilation units provide...

Portugal has technical recommendations and standards regarding ventilation rates in naturalventilation systems.