Legionnaires in hot water

Hot water temperature and growth of Legionnaires:

• 70C to 80C (Disinfection range)
• 65C (Die within 2 minutes)
• 60C (Die within 32 minutes)
• 55C (Die within 5 to 6 hours)
• 50C (Survive but not multiply)
• 20C to 45C (Ideal growth range)
• Below 20C (Survive but are dormant)

          (Photo source from Wikipedia)

Prevention of Legionnaires Disease in hot water heat pump system:

• Operate heat pump hot water temperature at 65C.
• Pipe design to prevent stratification and stagnation of water in storage tank and pipe.
• Regularly clean & drain storage tank.
• Thermostatic mixing valve use hot water temperature at 65C.
• Remove scaling deposit and breeding ground for Legionellae.