Michal Michalkiewicz, Malgorzata Basinska
Bibliographic info:
35th AIVC Conference " Ventilation and airtightness in transforming the building stock to high performance", Poznań, Poland, 24-25 September 2014

An inherent element of the passive house is the system of exhaust ventilation in air supply. According to their class, air filters used in ventilation systems stop the contamination, but may also be the main source of secondary indoor contamination during long-term use.

The aim of the study was to determine the contamination of different air filters after several months of their continuous work. The weight of the filter and its pollution with dust and microbiological contamination were determined. Research was carried out for four sets of filters working in the experimental passive house in the Poznan University of Technology – DoPas. The measurements were focused on the quality of the microbiological contamination of air filters. During microbiological examination of filters, the following microorganisms were determined: the general count of mesophilic bacteria, the general count of psychrophilic bacteria, the count of Staphylococcus (Staphylococcus) mannitol positive (type α) and mannitol negative (type β), the count of Pseudomonas fluorescens bacteria, actinomycetes (Actinobacteria) as well as the general count of microscopic fungi. Performed measurements of studied microorganisms count revealed that psychrophilic bacteria, microscopic fungi and mesophilic bacteria were most numerous. Their count was about ten times higher in the intake duct filter than in the exhaust duct filter. After disinfecting air ducts their cleanliness level dropped from moderate contamination to low.