English

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 the indoor air quality (IAQ) assessment of ventilated enclosures it is useful to know therelative influence of key boundary conditions on the personal exposure and ventilationeffectiveness, for instance as a source of information on where to allocate the greatest effortin the design phase. CFD is used to predict ventilation effectiveness and personal exposure tocontaminant sources in a displacement ventilated room subject to variation of several keyboundary conditions.

Methods to measure airflow rates using tracer gas in single air handling units are well known.However, in some buildings, in particular in Singapore, rooms are often ventilated with two ormore units. An adapted methodology that should be used to measure not only the airflow ratesprovided by each unit, but also to determine the inter-units airflow rates and the globalventilation efficiency is presented.

After several cases of health problems in French schools, a methodology for health riskassessment related to indoor air quality (IAQ) was required. Based on measuredconcentrations in schools where acute symptoms possibly due to exposure to airborne sensoryirritants were reported, an index quantifying the sensory irritation potential was built andused. This paper focuses on one classroom where the index was successively applied withoutany ventilation system, after the implementation of passive ventilation grids and with amechanically controlled ventilation.

This paper reviews the previous attempts to evaluate the Indoor Air Quality (IAQ),investigates previously proposed IAQ factors and analyses the evaluation methods of thesefactors. The present work also introduces a new hypothesis of the optimum HVAC airsidesystem design of the surgical operating theatres to achieve the comfort and hygiene levels.The present work is devoted to propose and formulate a new scale capable of adequatelyevaluating the airflow pattern in the surgical operating theatres. The proposed new scale isproposed to cover the local and overall air quality evaluations.

The aim of this study is to analyse the impact of volatile organic compounds emissions from asolid flooring material on the concentration field in a ventilated room. A field study has beenconducted in the CSTB experimental house MARIA. Measurements were performed in a testroom recently equipped with a flooring material made of pine wood and under controlledventilation conditions. a-Pinene was selected as tracer from flooring VOC emissions. Velocityand temperature fields are measured in different points of the room.

This paper proposes a new mode of ventilation for indoor airflow. It uses a plate or a curvedvane to divert a jet of air directly into the breathing zone. Computational results show that withproperly selected diffuser locations and design air supply velocities, the proposed systemwould be able to maintain better thermal comfort with a smaller temperature differencebetween the head and foot level, and possibly lower energy consumption, when compared withconventional systems.

A number of different thermal manikins have been applied in literature to experimentallystudy the indoor environment. These manikins differ in size, shape and level of geometriccomplexity ranging from simple box or cylinder shaped thermal manikins to humanlikebreathing thermal manikins. None of the reported studies, however, deals with the influenceof geometry of the thermal manikin.

Split system air-conditioning units are commonly employed in residential buildings inthe tropics due to their convenience in terms of energy conservation, aesthetics,flexibility, acoustic performance and ease of operation. This paper presents ourfindings from a recent study of the IAQ and ventilation characteristics in a masterbed-room of a condominium unit in Singapore, employed with a split system airconditioningunit. The attached bathroom is equipped with an exhaust fan, whoseoperation and its impact on the resulting IAQ and ventilation characteristics was alsostudied.

The performance of a Personalized Ventilation (PV) system with regard to air qualityperceived by people was studied at three room temperature levels: 23, 26 and 29C. Thirtyhuman subjects participated in the experiment. The system supplied both isothermal (23, 26,29C) and non-isothermal (23C) outdoor air from an outlet attached to a moveable arm. Thesubjects were delegated with control of both airflow velocity and its direction. Physicalmeasurements performed with a breathing thermal manikin were used to explain the resultsfrom the human subject experiments.