contaminant

The role of ventilation in achieving acceptable indoor air quality is examined in the light of emerging challenges, alternative mitigation strategies and performance indices within the spatial and time matrix of the indoor environment. By considering the source of contaminants, their nature, transportation mechanism and participation in source-sink relationships, several studies have shown that it may not be feasible nor adequate to rely on ventilation alone to attain the desired level of exposure, especially with respect to airborne aerosolised droplets with infectious potential.

In a test cell equipped with an operating table, a medical lamp and a manikin representing the surgeon, air velocity and tracer-gas concentration were automatically measured at more than 700 points. Numerical simulations were performed too for analyzing air quality in operating rooms. The results showed that the distribution of the contaminants depends strongly on the presence of obstacles like medical equipment and staff.

How to avoid or reduce the influence of suddenly released contaminant when emergency occurs ? A 3D Full scale room with displacement and mixing ventilation system is numerically studied assuming contaminant released at certain positions in the room. IACS is adopted as an index that can be applied to determine ventilation strategy with the aim of defending indoor environment against contamination.

In Hong Kong, design and construction of new operating rooms and upgrading of older ones have been based on the UK Health Building Notes. In a case study, field measurements showed that the airflow and some design features did not tally with the specifed requirements.
As the risk of contamination in an operating room can be minimized through appropriate filtration and air distribution scheme, a CFD analysis was carried out with the simulation of the temperature distribution, airflow pattern and the contaminant dispersion.

The method of exposure prediction using the scales of accessibility of supplied air (ASA) and the scales of accessibility of contaminant source (ACS) is presented in this paper. The spreading performance of supplied air and indoor pollutants can be figured out by CFD simulation and then used for the prediction of contaminant dispersion. For the validation of the model, a traver gas measurement was conducted.

This study presents a critical analysis of assessment of ventilation systems effectiveness in terms of contaminant removal. For this purpose, experimental measurements are carried in a room of an experimental house called MARIA. Various ventilation scenarios are handled. The ventilated room is also equipped with a pine wood floor which emits several Volatile Organic Compounds which are considered as air pollutants here. Thereafter, based on boundary conditions given by measurements, Computational Fluid Dynamics (CFD) simulations are performed.

The aim of that study was to determine whether there was a quantifiable difference in biocontaminant levels between one school with a carpeted floor and another school with hard surface floor. During one year, air and floor dust samples were collected and analyzed. The results suggest that floor covering is not the major contributor to airborne levels of biocontaminants in nonproblem schools.

In time, ventilation ducts and accessories get dirty and this may lead to malfunction of ventilationequipment, fire hazard and especially a decrease in supply air quality. Repeated cleaningof the components can prevent these adverse effects. The frequency of cleaning dependson how easily different components get dirty.

The impact of airflow interaction on inhaled air quality and transport of contaminants betweenoccupants was studied in regard to pollution from floor covering, human bioeffluents andexhaled air, with combinations of two personalized ventilation systems (PV) with mixing anddisplacement ventilation. In total, 80 l/s of clean air supplied at 20C was distributed betweenthe ventilation systems at different combinations of personalized airflow rate. Two breathingthermal manikins were used to simulate occupants in a full-scale test room.