Fight against Legionella in warm water systems

Legionella can cause serious illness in humans through inhalation, and the levels are therefore regulated by legislation. ND Hot UVC units are developed and manufactured in Denmark for use in hot water up to 65 degrees, making them an ideal element in the fight against Legionella.
Knowledge about Legionnaires’ disease

Legionnaires’ disease is a type of pneumonia caused by the bacteria Legionella pneumophila. Legionella are bacteria that thrive in lukewarm, stagnant water. Infection can occur by inhaling water droplets (aerosols) contaminated with Legionella. As many different systems can spread aerosolized water, there are often multiple potential sources of infection, but showering is believed to be the most common route of transmission in homes (Source: Statens Serum Institut – Legionnaires’ disease).

Biofilm protects Legionella bacteria

Legionella can exist at various stages, including the MIF (Mature Infectious Form) where it has increased tolerance to heat and biocides, as well as a VBNC (Viable But Non-Culturable) phase where it is highly resistant to external influences. Legionella and biofilm are interconnected, as the biofilm protects Legionella. For example, in thermal disinfection, it is necessary to heat the entire pipe and biofilm to the desired temperature, which should be measured on the outside of the pipes (Source: EUDP2020 project ‘Legionella Secure and Energy Efficiency for Installations and Supply’, Interim Report 1, p. 10).

UVC hot water unit and Legionella

A UVC hot water unit effectively targets unwanted microorganisms when water is circulated past a UVC unit. This helps keep the levels consistently low in the circulating flow and reduces the risk of sudden blooms with increased health risks.

ND Water Hot UVC-units

Our UVC hot water units are developed and manufactured in Denmark for use in hot water up to 65 degrees. They are constructed from stainless steel 316 with an inner quartz glass where the bulb is mounted. This allows for bulb replacement without shutting off the water flow.

ModelCapacity liters per hourTemp.Suitable for:Lifespan:Product image:
ND Water Hot 40000-4,000 l/h0-65 degrees CelciusE.g.
Hot water tanks size 100-4,000 liters
or heat exchanger size 37-150 kW
Up to 16,000 hours / 2 years
ND Water Hot 80004,000-8,000 l/h0-65 degrees CelciusE.g.
Hot water tanks size 4,000-8,000 liters
or heat exchanger size 150-350 kW
Up to 16,000 hours / 2 years

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