Experimental systems have been built in laboratories worldwide to investigate the influence of various environmental parameters on the efficacy of UV germicidal irradiation (UVGI) for deactivating airborne microorganisms. It is generally recognized that data from different laboratories might vary significantly due to differences in systems and experimental conditions. In this study we looked at...

In-duct ultraviolet germicidal irradiation (UVGI) systems treat moving air streams in heating, ventilation, and air-conditioning (HVAC) systems to inactivate airborne microorganisms. UVGI system performance depends on air temperature, velocity, cumulative operating time, variations in exposure time and other factors. Annual simulations of UVGI efficiency and space concentration that accounted f...

Ultraviolet germicidal irradiation (UVGI) is increasingly used in health care facilities to kill airborne bacteria and control the spread of airborne infection among occupants. The most widely used form of UVGI is the passive upper-room lamps that generate a horizontal layer irradiance field above the occupied zone. In this study, the efficacy of killing airborne bacteria by upper-room UVGI in ...

Several approaches for the inactivation of bacteriophage lambda, including UV germicidal irradiation (UVGI) and the chemical agents Virkon-S, Chloros, Decon-90, and sodium hydroxide (NaOH), were compared. Virkon, NaOH, and UVGI caused a ≥7-log(10) reduction in phage titers. This study successfully describes several methods with potential for bacteriophage inactivation in industrial settings.

Interest in the nosocomial transmission of tuberculosis was reawakened in the late 1980s and early 1990s when more than a dozen institutions in the United States experienced major outbreaks. Subsequent recommendations to strengthen environmental controls emphasized proper ventilation. Ultraviolet germicidal irradiation (UVGI), although relatively inexpensive, was considered an adjunct measure.1...

Recently, the requirement to continuously collect bioaerosol samples using shorter response times has called for the use of real-time detection. The decreased cost of this technology makes it available for a wider application than military use, and makes it accessible to pharmaceutical and academic research. In this case study, real-time bioaerosol monitors (RBMs) were applied in elementary sch...

A comprehensive treatment of the mathematical basis for modeling the disinfection process for air using ultraviolet germicidal irradiation (UVGI). A complete mathematical description of the survival curve is developed that incorporates both a two stage inactivation curve and a shoulder. A methodology for the evaluation of the three-dimensional intensity fields around UV lamps and within reflect...

BACKGROUND Eggcrate upper-room ultraviolet germicidal irradiation (UVGI), an engineering control method for reducing the airborne transmission of infectious diseases, was recently developed as an alternative to conventional upper-room UVGI using conventional louvered fixtures. A UV screen, which is composed of open-cell eggcrate panels supported in a frame designed for a conventional suspended ...

A dimensional analysis of an 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. Com...

This case study examines the effect that Reynolds number of air flow has on population oflive pathogenic microorganisms during process sterilization using ultraviolet germicidalirradiation (UVGI) lamp in a closed air-duct. With this aim, first discussion is mathematicalmodel which regulates changes to terms percentage populationfor following live microorganisms: Escherichia coli, Mycobacterium ...