Scale model experiments give possibilities for analyses of the design conceptions of ventilation especially of air distribution in large enclosures. When simulating aerodynamic and thermal processes in scale models of room ventilation, the flow patterns are visualised and the air flow temperature and velocity are measured. The paper presents the results of experimental tests of the air mean velocity field in three different size models of the same ventilated room. The field maps of the air velocity mean value were analysed.

The pattern of airflow influences the propagation of airborne pollutants, the thermalenvironment and general comfort conditions. In designing a good HVAC system, it isideal to determine the airflow distribution in the occupied zone to ensure good quality ofair and comfort condition are provided to the occupants. In most instances, it may not befeasible to conduct such study experimentally. This paper presents an investigation on thepredictions of air movement within a room and compared them with the physicalmeasurements.This study is carried out in a seminar room at a University.

An efficient numerical method for solving the Reynolds-Averaged Navier-Stokes (RANS)equations with turbulence models for complex geometry and high Reynolds number flows isused to perform a highly-resolved computation of the turbulent flow in a strongly curved partof a ventilation duct.The three-dimensional incompressible RANS equations and the isotropic k-w two-equationnear-wall turbulence closure are written in generalized curvilinear coordinates in the strongconservation form.

Split-system air conditioning is increasingly usedapplications, owing to its low cost and installationboth for residential and commercialease. The indoor split-system unit iscommonly of the wall-mounted type and, due to its dimensions and position, very often itgives rise to appreciable air velocities and temperature gradients in the occupied zone of theroom. This work reports and discusses some experimental data collected in a test room withwall-mounted indoor unit, under different operating conditions.

The purpose of this paper is to evaluate the performance of four kinds of ventilation systems from the point of view of air exchange, indoor air pollution, and space heating load under Japanese conditions by numerical simulation. TVOC and CO2 are selected to characterise the indoor air quality impact to residents. The results show that the equivalent leakage area has great influence on air movement.

Recently well-insulated and well-airtightened houses are increasing in Japan. Those houses havesome problems of air quality because of formaldehyde from construction materials. Ventilationsystems have possibility to solve these problems. The authors have developed a simulation programfor designing building elements, equipment elements to keep balance among comfortabletemperature and humidity, good air quality and energy conservation. The effects of some ventilationsystems in multiple dwellings are revealed by the developed simdation program.

Particle deposition from turbulent duct flow is modelled and related to particle penetration of a ventilation system for a commercial office building. Three published turbulent deposition models capable of accommodating surface roughness are compared to experimental data and used to determine the penetration of 0.1 - 10 (m spherical particles through a sample duct run. Depending on the model employed, penetration fractions varied from 0.40-0.94 for 0.1 (m particles and 0.28-0.73 for 10 (m particles.

An efficient ventilation system is characterised by a well-organised and turbulence-controlled airstream that rapidly corrects disturbances in air quality and thermal comfort in the ventilated space.Air supply and exhaust conditions are investigated here in order to find stable flow conditions andan efficient elimination of both gas and solid phase contaminants. Heat and thermal comfortrequirements are also included.

The influence of natural convection on the thermal properties of insulating porous medium with air cavity is studied. Here, the combined effect of air movement in the air cavity and the air movement inside the insulation is evaluated with the help of numerical analysis. The influence of total natural convection on the thermal properties of mineral wool, loose-fill insulation, insulation made of small and large polystyrene ball with air cavity are studied. The results are presented in terms of dimensionless numbers and the temperature distribution across the insulation.

There is a growing demand for buildings to have a high indoor air quality environment. Twoof the main elements that contribute to this quality are temperature and air distribution withinthe occupied space. In modern office buildings particularly in hot climates, care must be takento design the most economical air distribution system that provides comfort for the occupants.There are many techniques available to predict the air distribution patterns in the space atdesign stage, but these are often not very accurate.