UV-C Disinfection
Chemical-free disinfection through ultraviolet radiation – scientifically explained
German Innovation Award
2020
WINNER
UV-C LED Water Disinfection Unit
Category: Transportation
The German Innovation Award recognises products and solutions across industries that stand out through user-centricity and added value compared to previous solutions.
This award stands for innovations that advance the industry through their originality, implementation and effectiveness. With 700 submissions, the German Innovation Award achieved great resonance.
Pioneering work for 15 years
In 2020, we were one of the first companies worldwide to bring a UV-C LED water disinfection unit designed for end users to the market. While UV-C LED technology existed before, we pioneered the development of a ready-to-use, consumer-friendly solution – making chemical-free water purification accessible for everyone.
WM Aquatec has a 15-year track record of innovation. In 2024, Silvertex USA LP was established as a US subsidiary to further expand our commitment to clean water solutions worldwide.
Contents of this page
- 1. What is UV-C radiation?
- 2. Mode of action at molecular level
- 3. Wavelengths and their effectiveness
- 4. UV-C LED vs. mercury vapour lamps
- 5. Effectiveness against various pathogens
- 6. UV-C LED applications (mobile, stationary, POU/POE)
- 7. UV-8 & UV-100 product lines
- 8. Ideal operating conditions
- 9. Limitations and restrictions
- 10. When are alternatives better suited?
1What is UV-C radiation?
UV-C radiation is part of the ultraviolet light spectrum with wavelengths between 200 and 280 nanometres (nm). This short-wave radiation is invisible to the human eye and practically does not occur in natural sunlight on the earth's surface, as it is almost completely absorbed by the ozone layer.
The germicidal effect of UV-C radiation was discovered as early as 1878 by Arthur Downes and Thomas Blunt. The first large-scale use for water disinfection took place in 1910 in Marseille, France. Since then, UV-C has established itself as one of the most effective physical disinfection methods.
The electromagnetic spectrum
UV-A
315–400 nm
Black light, tanning
UV-B
280–315 nm
Sunburn, vitamin D
UV-C
200–280 nm
Germicidal effect
2Mode of action at molecular level
The germicidal effect of UV-C radiation is based on absorption by nucleic acids (DNA and RNA) in the cells of microorganisms. The wavelength of 254 nm corresponds almost exactly to the absorption maximum of DNA at 260 nm.
When UV-C photons hit DNA molecules, they cause the formation of pyrimidine dimers – abnormal chemical bonds between adjacent thymine or cytosine bases in the DNA helix. These dimers prevent correct DNA replication.
Since the damaged microorganisms can no longer reproduce, they become inactivated – they are biologically dead, even though the cell structure initially remains intact.
The inactivation process
- 1UV-C photon hits microorganism
- 2Absorption by DNA/RNA in the cell nucleus
- 3Formation of thymine dimers (T=T)
- 4DNA strand breaks and cross-links
- 5Replication becomes impossible → inactivation
Important: Photoreactivation
Some bacteria possess repair enzymes (photolyases) that can be activated by visible light and repair thymine dimers. This process is called photoreactivation. Therefore, a sufficiently high UV dose is important to overwhelm the repair capacity. With correct dosing, this effect plays no role in practice.
3Wavelengths and their effectiveness
Not all UV-C wavelengths are equally effective. Germicidal efficiency varies considerably within the UV-C spectrum:
| Wavelength | Relative effectiveness | Radiation source |
|---|---|---|
| 222 nm (Far-UVC) | ~60% | KrCl excimer lamps |
| 254 nm | 100% (reference) | Low-pressure mercury vapour |
| 265 nm | ~95% | UV-C LEDs |
| 275 nm | ~80% | UV-C LEDs |
| 280 nm | ~65% | UV-C LEDs |
WM Aquatec UV-C LED: 265 ± 5 nm
Our UV-C LED modules emit at 265 ± 5 nm – close to the DNA absorption maximum at 260 nm. Classical mercury vapour lamps operate at 254 nm and are considered the 100% reference in research; modern UV-C LEDs at 265 nm are in practice even closer to the theoretical optimum for DNA inactivation.
The UV dose: Decisive for effectiveness
The disinfection effect is determined by the UV dose (also called UV fluence), measured in millijoules per square centimetre (mJ/cm²):
UV dose (mJ/cm²) = irradiance (mW/cm²) × time (s)
For a 4-log reduction (99.99% inactivation) of E. coli, approximately 25 mJ/cm² is required. The DVGW standard W294 prescribes a minimum dose of 400 J/m² (= 40 mJ/cm²) for drinking water.
4UV-C LED vs. mercury vapour lamps
Traditionally, low-pressure mercury vapour lamps are used for UV-C disinfection. Modern UV-C LEDs offer decisive advantages, particularly for mobile applications:
UV-C LED Technology
- Instantly ready – no warm-up time
- Mercury-free – environmentally friendly
- Compact – ideal for mobile systems
- Long-lasting – up to 10,000+ operating hours
- Energy-efficient – low power consumption
- Robust – resistant to vibrations
- Power-on-Demand – active only during water flow
- Unlimited switching cycles – ideal for intermittent operation
Mercury vapour lamps
- Optimal wavelength – exactly 254 nm
- High output – for large flow rates
- Warm-up time of up to 15 minutes required
- Contains toxic mercury
- Sensitive to vibrations
- Larger form factor
- Often requires constant operation
Minamata Convention: 100% mercury-free
Our UV-C LEDs are completely mercury-free and therefore compliant with the Minamata Convention – a global UN treaty (adopted 2013, in force since 2017) protecting human health and the environment from anthropogenic mercury emissions. 134 parties, headquartered in Geneva.
WM Aquatec relies on UV-C LED technology – honoured with the German Innovation Award 2020. Our UV-C LED modules are instantly ready, extremely compact and specially optimised for mobile applications in motorhomes, boats and expedition vehicles.
5Effectiveness against various pathogens
UV-C radiation is effective against a broad spectrum of microorganisms, with the required dose varying by pathogen type:
| Pathogen type | Examples | Required dose (99.99%) | Effectiveness |
|---|---|---|---|
| Bacteria | E. coli, Legionella, Salmonella | 10–25 mJ/cm² | Very high |
| Viruses | Norovirus, Rotavirus, Hepatitis A | 30–60 mJ/cm² | Very high |
| Yeasts & moulds | Candida, Aspergillus | 50–100 mJ/cm² | High |
| Protozoa (vegetative) | Giardia lamblia | ~10 mJ/cm² | High |
| Protozoan cysts | Cryptosporidium | 10–20 mJ/cm² | High |
| Bacterial spores | Bacillus subtilis | 50–100 mJ/cm² | Medium |
Advantage against parasites
Unlike chemical disinfectants such as chlorine, UV-C is particularly effective against Cryptosporidium and Giardia – parasites that are largely resistant to chlorine and can cause severe diarrhoeal diseases.
6UV-C LED solutions for every use case
Whether mobile or stationary, at a single tap or at the building inlet – WM Aquatec UV-C LED systems adapt to your application and reliably deliver germ-free water in any scenario.
Mobile Use
Clean water – anywhere, anytime
Our mobile UV-C LED water disinfection devices provide the highest level of safety and flexibility on the go – whether camping, in an RV, on a boat, or in remote areas. Up to 99.999% of all germs are eliminated chemical-free. The devices can also be integrated into mobile water treatment systems – with maximum efficiency and minimal maintenance.
- Effective disinfection – up to 99.999% of all germs without chemicals
- Mobile & flexible – ideal for RVs, boats, camping
- Easy installation – compact design for quick setup
- Energy efficient – minimal power consumption with UV-C LED
- Eco-friendly – no residues, no taste change
- Low maintenance – durable LEDs with up to 10,000 operating hours
Stationary Use
Reliable water disinfection for stationary applications
Our UV-C LED water disinfection systems provide a sustainable, chemical-free solution for clean water in households, businesses and industrial applications. They integrate seamlessly into existing Point-of-Use (POU) and Point-of-Entry (POE) water supply systems. Intelligent sensors monitor performance continuously, while durable LEDs minimise energy consumption.
- Effective disinfection – reliably eliminates up to 99.999% of all germs
- Versatile – ideal for households, businesses, medical facilities, industry
- Seamless integration – easy installation in POU and POE systems
- Eco-friendly & low maintenance – no chemicals, low operating costs
- Maximum safety – intelligent sensors monitor performance and water flow
Point-of-Use (POU)
Directly at the tap
Our UV-C LED disinfection systems for Point-of-Use provide safe, efficient and sustainable water treatment directly at the point of consumption – ideal for kitchens, bathrooms, medical practices, laboratories and commercial applications. Up to 99.999% of all germs are eliminated – with no impact on taste or odour and without frequent filter replacements.
- Direct water disinfection – clean drinking and utility water exactly where needed
- Germ-free without chemicals – no residues, no taste impact
- Easy installation – compact design for flexible retrofitting
- Low maintenance & long lifespan – up to 10,000 operating hours without filter changes
- Sustainable – minimal power consumption with maximum performance
Point-of-Entry (POE)
Whole-building protection
Our UV-C LED disinfection systems for Point-of-Entry provide effective, chemical-free water disinfection directly at the main water inlet. The entire building – residential, commercial or industrial – is reliably supplied with germ-free water before it enters the individual pipelines. Ideal for hotels, hospitals and industrial applications with the highest hygiene standards.
- Comprehensive disinfection – protects the entire plumbing system at the main inlet
- Germ-free without chemicals – eliminates bacteria, viruses and germs without chlorine
- Easy integration – ideal for residential homes, hotels, hospitals, industry
- Low maintenance & long lifespan – UV-C LEDs with up to 10,000 operating hours
- Sustainable – no filter replacements, low power consumption
7Our UV-C LED product lines
Two scalable product series for mobile and stationary applications – from compact POU modules to POE systems with BUS connectivity.
UV-8 series
Point-of-Use for mobile and stationary use
With a flow rate of up to 8 l/min (approx. 2.1 GPM), all models of the UV-8 series are ideal for motorhomes, caravans and yachts with up to three outlets – but also suitable for stationary use, e.g. under the kitchen sink. This plug-and-play solution impresses with intelligent connections, high-quality housing and integrated function monitoring.
Technical data UV-8 series
Flow rate: 0.3 – 8.0 l/min (0.08 – 2.11 GPM)
Supply voltage: 11 – 30 VDC (110 – 250 VAC optional)
Power: 5 W (4 W for UV-8 eco and eco AIO)
LED lifespan: 10,000 h (operating mode)
Wavelength: 265 ± 5 nm
Ambient temperature: max. 50 °C (122 °F)
Rec. water temperature: 1 – 40 °C (34 – 104 °F)
Disinfection performance: 99.999% @ 2 l/min · 99.99% @ 5 l/min · 99.9% @ 8 l/min
¹ Reduction of E. coli (turbidity < 1 NTU, UVT > 98%)
Available models
UV-8 eco
- Incl. flow sensor
- Onboard function monitoring
- Optical status indicator
UV-8 act
- Incl. flow sensor
- Onboard function monitoring
- Optical status indicator
- Acoustic signal notification
UV-8 safe
- Incl. flow sensor
- Onboard function monitoring
- Optical status indicator
- Acoustic signal notification
- External power supply monitoring
- Flow sensor monitoring
UV-8 steel
- Incl. flow sensor
- Onboard function monitoring
- Optical status indicator
- Acoustic signal notification
- External power supply monitoring
- Flow sensor monitoring
- High-quality stainless steel housing
UV-8 eco AIO
- Incl. flow sensor
- Onboard function monitoring
- Optical status indicator
- Incl. activated carbon pre-filter
UV-8 steel AIO
- Incl. flow sensor
- Onboard function monitoring
- Optical status indicator
- Acoustic signal notification
- External power supply monitoring
- Flow sensor monitoring
- High-quality stainless steel housing
- Incl. activated carbon pre-filter
UV-100 series
Point-of-Use & Point-of-Entry for higher flow rates
The UV-100 OP series offers maximum operational safety through monitoring of temperature, UV intensity and functionality via the blue backlit OP-162 operation panel. Designed for seamless integration into Point-of-Entry (POE) and Point-of-Use (POU) applications, suitable for residential, healthcare, industrial environments and more.
Technical data UV-100 series
Supply voltage: 23 – 25 VDC
Power: 38 W
LED lifespan: 10,000 h (operating mode)
Wavelength: 265 ± 5 nm
Ambient temperature: 0 – 35 °C (34 – 95 °F)
Rec. water temperature: 0 – 40 °C (34 – 104 °F)
Operating pressure (max.): 6.9 bar (100 PSI)
Disinfection performance: 99.999% @ 30 l/min · 99.99% @ 50 l/min · 99.9% @ 100 l/min
¹ Reduction of E. coli at turbidity < 1 NTU and UVT > 98%
Available models
UV-100 OP
- Flow rate up to 100 l/min (26.4 GPM)
- Operation panel with 1 × input (flow sensor/switch), 2 × output (relay/0–10 V)
- Multilingual navigation
- BUS-ready (PROFINET)
UV-100 OP/MB40
- Flow rate up to 40 l/min (10.5 GPM)
- Incl. pre-filter
- Built-in flow sensor
- Multilingual operation panel
- BUS-ready (PROFINET)
UV-100 OP/LB60
- Flow rate up to 60 l/min (15.8 GPM)
- Incl. pre-filter
- Built-in flow sensor
- Multilingual operation panel
- BUS-ready (PROFINET)
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8Ideal application areas
UV-C disinfection is the optimal choice when the following conditions are met:
Water quality
- Clear water with low turbidity (<1 NTU)
- Low UV absorption (high transmission)
- Pre-filtered water without suspended particles
Application scenario
- Direct consumption after disinfection (point-of-use)
- Immediate disinfection without waiting time desired
- No taste change desired
9Limitations and restrictions
Despite its advantages, UV-C disinfection has clear limitations that must be considered in the application decision:
No depot effect
UV-C only works at the moment of irradiation. After treatment, the water can immediately become contaminated again. For longer tank storage, an additional preservative measure (e.g. silver ions) is required.
Turbidity and particles
Suspended particles and turbid water absorb UV-C radiation and can protect microorganisms in their shadow. At turbidity above 4 NTU, effectiveness drops drastically. Pre-filtration is mandatory.
No effect against pollutants
UV-C does not remove chemical contaminants such as pesticides, heavy metals, chlorine or nitrate. For these substances, additional activated carbon or membrane filtration is necessary.
Biofilm remains unaffected
UV-C radiation cannot penetrate biofilm on tank walls and in pipes. Existing biofilm must be treated by other measures (cleaning, silver ions).
10When are alternatives better suited?
In certain situations, other disinfection methods are better suited or should be used supplementally:
| Situation | Problem with UV-C | Recommended alternative |
|---|---|---|
| Extended water storage in tank | No long-term effect | Silver ion preservation → |
| Very turbid or particle-rich water | Shadow effect, low effectiveness | Pre-filtration + UV-C |
| Biofilm problems in tank | UV-C cannot reach surfaces | Silver ions + tank cleaning → |
| Chemical contaminants | No effect | Activated carbon/membrane filter |
| No electricity available | Operation not possible | Silver ions (powerless) → |
Recommendation: Combined approach
For optimal water hygiene, we recommend combining multiple technologies:
Conclusion
UV-C disinfection is a highly effective, chemical-free method for water disinfection. The technology reliably eliminates bacteria, viruses and parasites without altering taste or producing harmful by-products.
For mobile use in motorhomes, boats and expedition vehicles, UV-C LED is the optimal choice – instantly ready, compact and robust. In combination with silver ion preservation for the tank, this technology offers comprehensive protection.
Important: UV-C does not replace pre-filtration and offers no depot effect. For complete water hygiene, a multi-stage system is recommended.