Costs are one of the main decision factors for the selection of domestic ventilation systems.This often leads to a ventilation system that just meets the requirements of buildingregulations at the lowest initial costs. Decision makers are often not aware of the impact of thequality of the ventilation system on life cycle costs, not only for the ventilation system itselfbut also for the building, as a result of complaints or even damage due to a poor functioningventilation system.
The problem of the hygienic state of air-conditioning installations in many countries is still treated with limited attention and, in general, this issue is disregarded both when systems are designed and when the maintenance of already operating system is performed. In order to highlight problems resulting from contamination of the installation, microbiological assessment of air conditioning systems in a hospital was carried out. The measurements particularly pointed to increased microbiological contamination of air and dust deposited in the system just downstream of the sound attenuators.