Abstract
If conditions, such as a source of nutrition and temperature and relative humidity, are gathered, microbes will propagate. Now, almost all buildings are equipped with air-conditioning. Since particulate matters will collect within an air-conditioning system and the temperature-and-relative-humidity conditions in an air-conditioning system will become good environment for growing of microbes if time passes, contamination caused by microbes becomes remarkable. This paper describes the present condition of microbial contamination and the countermeasures against the microbial contamination in an air-conditioning system. In order to reduce the microbial contamination caused by an air-conditioning system, it is important to remove the pollution source, for example by cleaning air-conditioning system and/or introduce sterilization (UVGI, ozone) system, etc.
