OPERATION TIME OF THE VENTILATION SYSTEM AS A CAUSE OF MICROBIAL CONTAMINATION OF THE INFILTRATION FILTER
Original hosted in "MACE", contributed by Social Updater
Two identical ventilation systems having glass fiber bag filters as fine filters (EU7) without pre-filters located in the same building, were monitored for three and four months during winter and spring. One ventilation system (A) operated continuously at full capacity during days and nights and the other (B) operated periodically during days from 6 a.m. to 9 p.m. The relative humidity and temperature were measured continuously in outdoor air and in finefilter bags. Air, surface and filter material samples were taken to evaluate the extent of microbial contamination with viable fungi and bacteria. The conditions of filter units were dryer and warmer in the system B than in the system A. Filter and air of the system A with higher relative humidity were less contaminated by microbes and the contamination was more evenly spread in the filter than in the system B.