LEDS coming online
UV-C LED systems have been part of several case studies, including university pilot studies, National Science Foundation (NSF) grants and recently a Cooperative Research and Development Agreement (CRADA) between the US EPA, Washington University and a major UV manufacturer. These case studies, dating back to 2012, offer a reliability and longevity indicator that is often desired in something as important as potable water treatment. The primary goal of the US EPA CRADA agreement was to test and validate a water treatment system incorporating UV-C LED disinfection technology. The device targeted higher flowrates and more challenging water qualities than addressed with currently available UV-C LED commercial systems. The CRADA showed efficacy of the world’s first commercially available UV-C LED POE treatment system.
Growth of UV LED systems in the market
The increasing demands and need for sustainable solutions to health and quality of life related issues should guarantee an increasingly important place for UV-C LED technology in the realm of improved water treatment methodologies. Continuous improvement in performance and cost reduction is already allowing this to happen and will only increase market penetration in the future.
While conventional mercury-lamp-based UV disinfection systems will continue to dominate some sectors of the market, more especially high-flow commercial and industrial applications, there are additional factors (such as cost of ownership and long-term maintenance requirements) that will drive the adoption of UV-C LED devices in a growing number of applications. Due to the unique properties of uv-c leds, fouling is much less of a concern as heat discharge is managed at the back of the system using heat sink technology rather than the quartz lamp/sleeve/ water interface, where fouling and consequent reduced UV transmission can occur in water containing hardness minerals. In conventional systems, instant -on LED technology allows for powering the LEDs only when water is flowing, thereby eliminating the heat build-up that results in fouling during stagnant (no flow) conditions often found in systems using permanently powered mercury lamps. Elimination of the familiar hot water shot associated with conventional systems not equipped with a temperature management dump valve is an added benefit. The instant on/off properties of LEDs and consequent ability to be powered only when needed drastically reduces lamp replacement intervals when compared with conventional mercury lamps. Based on average household water demand of 2-3 hours per day, the replacement interval for LEDs is typically five years, compared to annual replacement of mercury lamps. The on demand advantage, together with flow regulated power demand, means that the long-term electrical energy requirement is substantially lower for UV-C LED systems.
