Warm water (legionella control)

The systems of the PURION® H series have been specially developed for use at water temperatures above 40°C to combat legionella in drinking water systems and swimming pools. These systems work with a special amalgam technology and the lamps used also achieve their optimum UVC yield in the warm and hot water range.

Legionnaires' disease or legionellosis is a dangerous form of pneumonia that is often fatal. In the USA alone, it is estimated that 15,000 deaths occur annually as a result of Legionella infection. The main route of infection is the inhalation of aerosols containing the pathogen. There is therefore a risk of infection wherever water vapours are produced and a water-air mixture contaminated with bacteria can form. This danger is particularly present in showers, but also at washbasins.

Other areas of risk

  • Showers in hotels, hospitals, old people's homes
  • Whirlpools and other swimming pools with bubbling water attractions
  • Ventilation systems with wet scrubbers
  • Areas where water is sprayed for cooling and humidification purposes

Particularly vulnerable risk groups

  • Stressed people
  • Traveller
  • Older people
  • Sick people (organ transplant patients, chemotherapy patients, HIV-infected persons)
  • Heavy smokers and people with high alcohol consumption

The operation of low-temperature circuits <60°C for the purpose of saving energy significantly increases the risk of legionella formation. Thermal disinfection of pipes, fittings and water is only possible at temperatures above 60 °C.

The aim is therefore a DVGW-compliant (worksheet W551) procedure to avoid legionella and other biological contamination despite lower temperatures in the hot water circuit:

  • Reducing the temperature in the hot water circuit by 20 degrees to realise energy savings
  • Every 2 weeks 1 day temperature increase to ensure thermal disinfection
  • Installation of a special PURION H UV system (up to max. 90°C) for continuous UV-based disinfection of the circulating hot water (installation downstream of the boiler in the riser pipe).

Model calculations show that with this approach, taking into account all significant costs, up to €460 can currently be saved per single-family house and up to €1,190 per multi-family house (cf. derivation in the document "Savings potential through PURION H systems" in the download).

Amortisation calculation:

All units of the PURION® H series are made of electropolished stainless steel approved for drinking water. They are supplied ready to plug in with connection cable and earthing contact plug. The units are designed for an irradiation dose of 400 J/m². All units can also be equipped with an operating hours and/or UVC intensity monitor.

A complete PURION installation set is available for all systems.

For further details and dimensions, please refer to the corresponding data sheet.