Studies have documented that personalized ventilation, which provides clean air at each officeworkplace, is able to improve substantially the quality of air inhaled by occupants. However,the interaction between the airflow generated by personalized ventilation and the airflowpattern outside the workplaces has not been studied in detail. This paper presents a study onthe performance of a personalized ventilation system installed in a full-scale test room with anunderfloor air distribution system.
The paper deals with a numerical investigation of the influence of ventilation and airconditioning on the distribution of pollutant concentrations in buildings. The model used is acoupled thermal and airflow model where the room is divided into 18 sub-zones.Temperatures and pressures are determined from the mass and energy conservation equationsin each sub-zone, while airflow rates between two adjacent sub-zones are determined from theBernoulli equation.
In 2003, the World Health Organization received reports of ‘Severe Acute Respiratory Syndrome (SARS)’ in various parts of the World. Until 13 June 2003, there were 1755 people affected by atypical pneumonia in Hong Kong. While the mechanisms of the SARS a
A wind tunnel dispersion modeling study was conducted to investigate exhaust contamination of hidden versus visible air intakes. A hidden intake is typically on a building sidewall or on the sidewall of a roof obstruction opposite the exhaust source. A visible intake is at roof level or on top of
an obstruction, directly above the hidden intake. Overall, the study has shown what designers suspected: placing air intakes on building sidewalls is beneficial when the stacks are on the
Major sanitory problems occuring at industrial workplaces are induced by air contaminants. They represent a high financial cost. This paper sums up the main steps and results of the European Research project COST that has developed and optimized a system specifically geared to the local capture of contaminants : the REinforced EXhaust System (REEXS)
In this study, associations between concentration levels of airborne particles and fungi were examined in 14 houses in Brisbane. No association was found between the fungal spore and submicrometer particles or PM2.5 concentration, but a weak link was found between fungal and supermicrometre particle concentrations : similarity in behaviour lies in the relation of the contaminant with the distance from the source.
This study compares the contaminant concentration obtained from simple models with contaminant concentration fields obtained from CFD simulations, for various rooms and source configurations. Airflow and contaminant distributions were simulated.
This paper presents a method to determine the amount of oil residues in HVAC components surfaces. That method has been validated. It appears that the oil concentration of studied HVAC components depends on the technique used for their manufacturing.
The objective of the European project AIRLESS was to develop strategies, principles and protocols to improve and control the performance of HVAC systems and their components to be incorporated in codes and guidelines.This paper is a sum-up fo the first-phase of the AIRLESS project : definition of air pollution caused by HVAC systems, investigation to prevent this pollution and definition of strategies to keep away that pollution.
The dispersion of contaminants in an office environment has been investigated. The first experiment was made in a full-scale typical office equipped with two workstations located in the middle of the room and separated by a low-level partition, and the second experiment took place in a room separated in two halves with a low level partition, with one workstation at each corner. A constant injection of tracer gas allowed the measurement of the concentration of contaminant in the chamber for both the layouts.