Kokotti H., Halonen R., Kujanpää L., Keskikuru T., Lehtimäki M., Taipale A., Reiman M.
Bibliographic info:
23rd AIVC and EPIC 2002 Conference (in conjunction with 3rd European Conference on Energy Performance and Indoor Climate in Buildings) "Energy efficient and healthy buildings in sustainable cities", Lyon, France, 23-26 October 2002

The fine filter (EU7) was included in the ventilation system which operated at full capacity only during working days. The first three months the filter was located in the ventilation system of the office building and it was later moved for one month period into the laboratory chamber. The aim of the study was to investigate whether particles or microbes are released from the filter during the turn off and start up of the fan. The released particle (size range of 0.3 m) concentration was below 10 #/dm 3 in normal field conditions. In some cases the particle concentrations increased also when the fan was turned on. The concentration exceeded simultaneously 100 #/dm_. The final material sampling after field and laboratory tests revealed the more abundant microbial growth in lower parts than in the upper parts of the filter bag. During start up of the fan, release of airborne microbes e.g. Aureobasidium could be observed, however, only during field tests. The possible explanation for that could be the change in the conditions.