The aim of this research is focused on dust and bacteria removal evaluation from a ductwork of a central heating and air-conditioning system by means of a commercial electronic air cleaner. Bacteria removal and microrganisms viability are measured under steady flow conditions following two different sampling-analysis strategies. The first is based on a surface air system (SAS) sampler using a general plate count agar (PCA) medium; the second uses fluorescent stains to distinguish and count viable and non viable cells by means of epifluorescence microscopy. Inserting the electrostatic barrier, an informative bacterial removal obtained averaging the overall results is found around 88%. The ratio viableon-viable, calculated on the basis of the epifluorescence measurements, changes significantly in consequence of the passage through the electronic filter. Beside the removal efficiency a viability attenuation of 50% suggests a further positive effect adopting an electrostatic barrier in a ventilation duct.
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