Respiratory Influenza and UVC

ASHRAE has taken a strong stance in support of continuous UVC. Regarding the reopening of schools, this industry standard organization has published descriptions of available technology, noting the effectiveness of continuous UVC in reducing airborne infection risk for appropriately designed continuous UVCsolutions17. These robust statements build upon the pre-COVID guidelines that support continuous UVC and […]

Public Restroom Review

Fluid dynamics analysis has demonstrated alarming results. Toilets produce aerosols during the flushing process, with 40-60% measured particles rising above the toilet bowel(>100cm) DURING the flushing cycle with continued airborne diffusion in the post flushing period (due to measures velocities of > 5 m/s)10. There is a growing body of literature on air and surface […]

UVGI design basics for air and surface disinfection (2000)

Lethal to microorganisms, ultra-violet radiation in the range of 2250 to 3020 angstroms is used in a variety of disinfection applications, a process referred to as ultra-violet germicidal irradiation (UVGI). Since the first UVGI system was successfully implemented for disinfecting the municipal water system in Marseilles, France, in 1909, the disinfection of medical equipment using […]

SARS Coronavirus UV Susceptibility

Severe Acute Respiratory Syndrome (SARS) virus is an emerging respiratory infection that has caused outbreaks in health care settings (Ho et al 2003, HWFB 2003). SARS virus is a new variant of the coronavirus family and transmits through the air and by direct contact. (He et al 2003, CDC 2003). SARS coronavirus is one of […]

JBJS – Ultraviolet Lighting During Orthopaedic Surgery and the Rate of Infections

All procedures that were performed before the installation of the ultraviolet lighting used horizontal laminar airflow, whereas all procedures that were performed after that date used ultraviolet lighting without laminar airflow. Factors associated with the rate of infection were analyzed. Results: Over a nineteen-year period, forty-seven infections occurred following 5980 joint replacements. The infection rate […]

Guidelines for Design and Installation

The International Ultraviolet Association (IUVA) Draft Guidelines for UVGI Air Treatment Systems are international voluntary guidelines developed under the auspices of the IUVA. This consensus represents a substantial agreement reached by parties in Academia and Industry with direct or indirect interests in air treatment with UVGI and related technologies. This consensus signifies the concurrence of […]

Design and Optimization of UVGI Air Disinfection Systems

Mathematical models of the response of populations of microorganisms exposed to ultraviolet germicidal irradiation (UVGI) are developed that include two-stage response curves and shoulder effects. Models are used to develop a C++ computer program that is capable of predicting the performance of UVGI air disinfection systems. The algorithms are based on models for 1) the […]

Dimensional Analysis of UVGI Air Disinfection Systems

A dimensional analysis of ultraviolet germicidal irradiation (UVGI) air disinfection system within a diffusely reflective enclosure is performed using the Buckingham pi theorem. The eight dimensionless parameters obtained include the duct aspect ratio, the lamp aspect ratio, the reflectivity, and terms that incorporate the UV dose, airflow, duct dimensions, and lamp location coordinates. Computer simulation […]