Case Study from HydroFLOW Italy
Hotel Legionella control at Grand Hotel Terme di Comano
Hotel Legionella control kept failing at Grand Hotel Terme di Comano, a 55-room spa hotel over four floors. Legionella periodically reached 10³ to 10⁴ CFU/L, chlorine and high-temperature sanitisation gave only temporary relief, and biofilm in the pipework kept reseeding the system. One HydroFLOW® C100 was installed on the main incoming supply and two P60 units on the hot-water manifolds after the boilers, within a six month programme that included thermal shock and purging. After a brief spike as organic material released from the pipework, certified testing found Legionella below 10 CFU/L in every sample, and levels were still compliant seven months after the last thermal shock.
The Challenge
- Hotel Legionella control kept failing as contamination returned after each sanitisation
- Legionella periodically reached 10³ to 10⁴ CFU/L
- Chlorine and high-temperature sanitisation gave only a temporary reduction
- Persistent biofilm remained within the pipework
- The 55-room hotel spans four floors, making system-wide control harder
The Solution
- Units installed: one HydroFLOW® C100 and two HydroFLOW® P60
- Installation point: C100 on the main incoming supply, P60s on the hot-water manifolds
- Trial: six month programme, including thermal shock and system purging
- Previous treatment: chlorine and high-temperature sanitisation
Hotel Legionella control was approached as a whole-system programme, treating the incoming water and both hot-water delivery manifolds while thermal shock and purging ran alongside. Levels spiked initially as accumulated organic material released from the pipework. Certified June testing then found Legionella below 10 CFU/L in every sample, and the plumber reported cleaner boilers, pipes, filters and shower heads.
