UV-C LED technology is a modern disinfection method that uses ultraviolet light emitting diodes to inactivate bacteria, viruses and other microorganisms. Operating within the 200–280 nm range, UV-C LEDs provide a mercury-free approach to disinfection for water, air and surface applications. This page explains how UV-C LEDs work, their advantages over traditional UV systems and where they are used in real-world environments.
What is UV-C?
UV-C is widely recognised as the germicidal portion of the ultraviolet spectrum, with the ability to inactivate bacteria, viruses and other microorganisms. Its unique wavelength range allows it to disrupt cellular processes at a molecular level, making it highly effective for disinfection. To understand why UV-C performs this role, it is important to look at how ultraviolet light is categorised within the electromagnetic spectrum.
UV-C radiation used for disinfection is most effective at a wavelength of 264nm.
UV (ultraviolet) light is a type of radiation that can be found in the electromagnetic spectrum and is measured in Nanometers (nm). Invisible to the human eye, UV is an effective disinfectant due to the density of its wavelength.
There are four ranges to UV light – UV-A, UV-B, UV-C and Vacuum-UV:
- UV-A – otherwise known as black light, it has the longest wavelength, ranging between 315nm to 400nm.
- UV-B – known as the medium wavelength, it ranges between 280nm and 315nm.
- UV-C – the shortest wavelength, it ranges between 200nm and 280nm.
UV-C is germicidal, meaning it can be used effectively as a disinfectant to kill microorganisms, such as bacteria and viruses.
When the DNA of microorganisms absorbs UV light, it stops them from being able to reproduce and duplicate, thereby preventing their growth.
What is a (UV-C) LED?
Light-emitting diodes (LEDs) are semiconductor devices that are made up of multiple layers of substrate materials. They can be designed so that a wavelength can be inputted and emit photons in the UV-C range that can be used to stop the replication of bacteria.
UV-C LEDs perform the same functions of conventional mercury-vapor lamps but have many benefits in comparison.
- Environmentally friendly – conventional UV lamps use heavy metals that are difficult to handle and cost a great deal to dispose of safely.
- Small design footprint – LEDs are much more compact compared to their mercury-vapor counterpart, meaning they can be integrated easily into new innovative designs.
- Instant-on/off – UV-C LEDs work instantly, so there is no need for a warm-up time that is a common constraint of mercury-vapor lamps.
- Unlimited cycling – on/off cycles do not impact the life of the LEDs, meaning there is an unlimited scope for lamp cycling.
- Temperature independent – LEDs can emit photons from a different surface as their heat emissions. They can be designed so that if UV-C LEDs are being used in water purification, they will not transfer heat into the water.
- Wavelength selection – One of the greatest benefits of UV-C LEDs is that users can configure them to choose a specific wavelength that is best suited for maximum absorption of light for the chosen microorganism.
LEDs produce a selected wavelength using minimal electricity. As power passes through the LED layers, it activates the desired wavelength, in this case UV-C.
The LED is then packaged to allow for electrical connection, thermal management, and physical protection. This helps maintain efficiency for the LED output and lamp life.
How Does UV-C LED Disinfection Work?
Different types of UV-C disinfection can work depending on the scale of the solution being implemented. However, the principles of how UV-C disinfection works remain the same.
An LED produces a pre-selected wavelength from a small amount of electricity. The LED then emits UV-C photons through the water that penetrate the cells and damage the nucleic acid in the microorganism DNA.
As these cells cannot replicate, it renders the harmful microorganism inactive. As a result, UV-C LEDs allow for high-intensity radiation to kill the bacteria in seconds, and its effectiveness is measured in LOGs.
UV-C LED Disinfection Technology
Ultraviolet disinfection technology has been the star performer in water and air treatment over the past two decades, due in part to its ability to provide treatment without the use of harmful chemicals.
UV represents wavelengths that fall between visible light and x-ray on the electromagnetic spectrum. The UV range can be further divided into UV-A, UV-B, UV-C, and Vacuum-UV. The UV-C portion represents wavelengths from 200 nm – 280 nm, the wavelength used in our LED disinfection products.
UV-C photons penetrate cells and damage the nucleic acid, rendering them incapable of reproduction, or microbiologically inactive. This process occurs in nature; the sun emits UV rays that perform this way.
AquiSense use Light Emitting Diodes to generate high levels of UV-C photons.
The rays are directed at viruses, bacteria and other pathogens to render those pathogens harmless in seconds.
Applications of UV-C LEDs
There are many applications where UV-C LEDs are being tested to see if they can become a solution to not just current disinfection challenges but our future ones too.
Drinking water disinfection, water purification, and treatment are where the technology is gaining traction as the solution is chemical-free, has no risk of creating harmful by-products, is an effective pathogen inactivation, and is very low maintenance.
As well as water, UV-C LEDs are offering disinfection for both air and surfaces. UV-C LED air purifiers for HVAC (heating, ventilation, and air conditioning) are being used increasingly in the commercial landscape.
There are numerous applications, from residential to commercial, healthcare, transport, life sciences, defence, and emergency response where UV-C LEDs are finding new uses:
| MARKET SEGMENT | EXAMPLE APPLICATIONS | UV-C LED BENEFITS |
|---|---|---|
| Residential | POE, Appliances, Faucets | Ultra-compact footprint, Plug and play (e.g. easy to retrofit), Low power draw |
| Commercial | Food and beverage service, Water dispensers and fountains | Ultra-compact footprint, Low power draw, No heating of water |
| Healthcare | HAI control, Dialysis, Dental | Mercury-free, Chemical-free, Durable (e.g. vibration resistance) |
| Transportation | RV and boating, Automotive, Aviation, Space | Chemical-free, Durable, Lightweight |
| Life Sciences | Bio-pharma, Ultrapure water | Point-of-use distribution, Mercury-free, Chemical-free |
| Defence/Emergency Response | Personal hydration, Remote treatment | Ultra-compact footprint, Lightweight, Durable (e.g. vibration resistance) |
UV-C LED Benefits
Mercury-Free
No mercury, no hazardous materials, and no specialised handling or disposal requirements.
Scalable Applications
From point-of-use to municipal systems, the PearlAqua range supports diverse water treatment applications.
Flexible Integration
Compact, durable systems designed for installation where traditional UV systems are not practical.
No Heat Transfer
UV LEDs do not heat the water, reducing fouling and maintaining stable UV output.
Instant On/Off
Full UV output instantly, with unlimited on/off cycling and no impact on lamp life.
Sustainable
High-efficiency UV-C LEDs deliver consistent performance without the use of harmful chemicals.
UV-C LED Technology – The Next Revolution
In much the same way that LEDs have revolutionised the display and lighting industries, UV-C LED technology is set to provide new, improved, and expanded solutions in both air and water treatment. Dual barrier, post-filtration protection is now available where mercury-based systems could not previously have been conceivably used.
| Attribute | Conventional Mercury Lamp | UV-C LED | Product Implication |
|---|---|---|---|
| Mercury Content | 5-200 mg | None | Safe disposal – no special handling |
| Lifetime | 5,000 – 15,000 hours | 10,000 hours | Flexible operation |
| On/Off Cycles | Max. 4 per day | Unlimited | Intermittent-flow friendly |
| Warm-up Time | Up-to 15 minutes | Instantaneous | Extended replacement intervals |
| Operating Surface Temp. | 100-600° C | Same as process water | Zero-flow friendly does not promote fouling |
| Architecture | Cylindrical tube | Point source | Versatile implementation |
| Durability | Fragile glass tube | Rugged semiconductor | Versatile operation |
| Wavelength | Polychromatic (200-300nm) Monochromatic (254 nm) | Selectable (250-300nm) | No wasted energy & targeted performance |
| Power Supply | 110-240V AC | 6-30V DC | Battery/Solar option |
Disinfection of Drinking Water
One area where UV-C LEDs are proving to be successful is in the disinfection of drinking water.
UV-C LEDs are being used to disinfect drinking water at various points in the treatment cycle, from source to consumption. It can take a few seconds for the water to become clean in a UV-C model, and the new technology allows for LEDs to be placed at a different point to ensure decontamination.
It works initially when a water reservoir is exposed to a number of high-powered LEDs that disinfect the water. They emit powerful UV-C photons in the range of 200 – 280nm that pass through the water, stopping the bacteria in the water from being able to reproduce.
Many newer systems have taken advantage of the compact size of the LEDs and can disinfect at the end stage of the drinking water journey – ensuring complete disinfection.
