MegaFan AirClean

by | Nov 12, 2020

Leeds University Conduct Report on UVC Performance Against Airborne Microorganisms

On the 2nd February 2017, Dr Louise Fletcher from the University of Leeds conducted a report on behalf of Plasma Clean; “The Evaluation of the Performance of UV device for the reduction in airborne microorganisms.” We have the full report, determining the performance of UVC for disinfection purposes, available on request.

Thanks to the great work from Dr Louise Fletcher and Plasma Clean Technical Director and Founder, Dr David Glover, this has helped propel UVGI to the forefront of safeguarding commercial buildings within the Coronavirus, as well as allowing us to develop a varied range of in-duct and stand alone UVC solutions for the last four years.

We were thrilled to see the lastest update of CIBSE COVID-19 Ventilation Guidance released in October, and hope this – teamed up with Plasma Clean findings – will help aid your project.

Ultraviolet light in the c-band range (225-302nm) is lethal to micro-organisms and is referred to as ultraviolet germicidal irradiation (UBGI). It is well known for its germicidal – or germ killing- properties and is used extensively for water and surface treatment. Historically airstream disinfection has proven less predictable. This is due to underspecifying the UVC dosage and poor design.

UVGI works by cross linking the nucleic acids (DNA & RNA) which prevents replication and proliferation of micro-organisms such as viruses, bacteria, spores, moulds, yeast and fungi.

It is important to use the correct UVC dosage in order to achieve high kill rates. Low intensity UVC can be used for surface treatment as there is a long UV-C exposure time whereas high intensity UVC is required for air treatment as the exposure time is short.

The UV dosage to achieve microbial kill varies considerably between micro-organisms, with spore forming microbes being more resilient to UV attack than vegetative cells, for example: microbial spores are akin to plant seeds and are adapted to withstand extreme environments wheras so-called vegetative cells are those which grow and divide – a plant seed can survive in, and actually requires, dry conditions whereas the vegetative new shoot after germination requires water.

Plasma Clean UVGI systems are sized to achieve up to 99+% microbial kill rate for common microbes based on UVC dosage tables in the scientific literature as well as independent testing carried out by Plasma Clean.