Milan Hotel: Legionella Control Without Chemicals Since 2017

Summary

Legionella control without chemicals was not a preference at Hotel Des Etrangers in Milan; it was the only option. Legionella kept returning to the hotel's domestic hot water system, but the installation was old enough that chlorine dosing risked corroding the pipework it was meant to protect. Biofilm had built up inside the pipes, giving the bacteria somewhere to shelter, and scale was affecting system performance. In December 2017 one HydroFLOW® C100 was installed on the cold supply and one P100 on the hot water delivery. During an initial cleaning phase, deposits detached from the pipe walls and were seen at the outlets. Since then Legionella has not reappeared, biofilm has been removed from pipe surfaces and no new scale has formed. This case study covers why chemicals were ruled out, the two installation points and what the cleaning phase looked like at the taps.