Towards energy efficient and healthy buildings: an overview how (not) to get a Legionella pneumophila infection

摘要

The total energy demand of energy efficient buildings raised some questions about the production of domestic hot water (DHW). One of the main reasons for the high energy demand is that DHW is produced, stored and distributed at temperatures above 55°C to mitigate the risk of infecting the DHW system with Legionella pneumophila. At these temperatures, L. pneumophila species growth is stopped and remaining species are effectively killed. Over the preceding two decades less research had been published on the progress in knowledge on the infection process and disinfection techniques. This paper offers an overview of the profitable conditions for Legionella pneumophila growth (lukewarm water between 20 and 45°C, stagnation, an acid environment and the presence of nutrients), infection process (profitable conditions, creation of aerosols, contamination process and the condition of the victim) and the effectiveness of disinfection techniques (temperature disinfection like pasteurization and shock disinfection, UV radiation, chemical treatment like the addition of free chlorine and copper-silver ionization), while keeping an equilibrium between energy efficient and healthy buildings.