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Mixing ventilation and displacement ventilation were compared in an intervention study inclassrooms. Particles, cat allergen and CO2, were measured in classroom air at different levelsabove the floor, during regular lessons. With mixing ventilation, the particle concentrationtended to decrease with height, with a stronger gradient occurring for larger particles. Withdisplacement ventilation, the particle concentration increased with height, except for particles>25 m. The displacement system thus tended to have a slight upward displacement effect onmost of the particles.

The thermal environment in vehicles varies greatly. The interaction of the cabin thermalenvironment, created by the HVAC system, the outdoor conditions as well as the occupants,is rather complex.In this regard, in order to improve occupants comfort, we thought of locally differentiatingthe parameters which influence peoples satisfaction.

The influence of uniformly distributed cooling load is investigated on the air velocity in theoccupied zone. The experiments have been carried out in a scaled test room of 6 6 2 mwith a scale factor 1:1.5. The room is equipped with nine vortex inlets. The inlets areuniformly distributed; every inlet supplies a cubical volume to remove the maximum possiblecooling load with a minimum airflow rate. The air supply rates based on floor area are set to30 m/(h m2). The cooling load generated by mannequins is uniformly distributed and variesbetween 0 and 180 W/m2.

Natural controlled ventilation is often ignored when buildings are designed. It is importantthat architects, property developers both commercial and residential, designers, engineers andthe general public be aware of guidelines (readily available) for proper indoor air quality.Mechanical engineers should realize that introducing supplemental fresh air ventilation intoheating, ventilating and air conditioning (HVAC) systems aids in improving indoor air qualityand often maximizes the efficiency of the HVAC systems.

This paper is about the application of active stack system to enhance natural ventilation inpublic housing in Singapore. About 86% of the population is staying in high-rise publichousing, known as Housing and Development Board (HDB) flats, which is designed fornatural ventilation. The main objective of this work is to assess the status of naturalventilation in a typical 4-room HDB flat using scaled model in the wind tunnel, and todevelop an effective active stack system to enhance natural ventilation in the flat.

This paper investigates the effect of ventilation on mould growth in a typical Japanese bathroom byuse of the fungal index which indicates the growth rate of a mould, Alternaria alternata S-78. Thebathroom was set in an artificial climate where the temperature and relative humidity (RH) werekept constant. The temperature, RH and fungal index in the bathroom were measured under severalventilation methods after taking a bath.

The purpose of this study is to estimate the accuracy of the Supply Rate Fulfilment (SRF)value measured by using tracer gas on a test house. The SRF is intended to evaluate quantityindex and is defined as the ratio of the effective supply rate to the substantial required freshair supply rate. The procedures to measure the SRF value with use of tracer gas techniques,which are constant concentration method and constant injection method, were shown. TheSRF values of the each room in the test house were measured.

The characteristics of the climate in Taiwan are high temperature and humidity. In order to solvethese basic problems in dwellings, a meteorological station was established in Fulong(northeastern part of Taiwan) to document the detailed microclimatic information of indoor andambient environments during 4 years. According to the hydrodynamics and thermal mechanics,the new ventilation strategy was developed with the thermal mass cooling-down systemconstructed as the porous floor in a full-scale climate chamber.

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.