Spatiotemporal distribution and the passive dispersal of fungal spores through HVAC systems

This study presents results from ex situ experiments conducted to a better understanding of the spatiotemporal distribution, passive dispersal and removal of fungal spores through HVAC systems. The study was conducted in a 50 square meters by 3  m high instrument room in a research building with HVAC systems. Plates withAspergillus flavus colony were attached upside down on the edge of the ceiling vent to imitate the mildew growing. Fungal spores were released for 10  min, collected and counted by the settle plate method in 2 h. Results show thatA. flavus spores dispersed to 3.6  m in 2 min and were evenly distributed in the room within 8 min. The concentration of spores decreased from 48 to 3–6 CFU/plate after 60 min and was lower than 1% after 120 min. Our results suggest that airborne fungal spores disperse and remove by HVAC systems efficiently. Without the exte rnal and internal source, the HVAC system could greatly reduce the fungal amount in the indoor air to the background level within one hour. This study provided the observed data of the transmission and retention of internal or external biological contaminants through HVAC system.
Source: Aerobiologia - Category: Environmental Health Source Type: research