English

This report describe the thermal performance and air distribution of a Kumamoto prefecturalindoor sports ground in Japan. The swirling flow type natural air ventilation system wasadopted in combination with environmental symbiotic technique, and attempts was made topositively harmonize the system with the environment. In the measurements, emphasis wasput on the identification of thermal environment and on the verification of the swirling flowtype natural air ventilation system.

In apartments of Korea, exhaust-only hood system is commonly installed for kitchen ventilation. However, as to resident's increasing complaints recently due to poor indoor air quality and hood noise, a careful review regarding kitchen ventilation system came to be in need. This paper presents a research that was conducted to improve ventilation problems in the existing kitchen of apartments. For this purpose, a field test has been carried out to examine the effect of range hood's exhaust airflow rates, and makeup air inlet's settings on kitchen ventilation efficiency.

Three very different task/ambient conditioning (TAC) systems were investigated in a climate chamber. Two desk-mounted TACS, the “Personal EnvironmentalModule” (PEM), intended for US offices, and the “ClimaDesk” (CDESK), intended for European offices, were compared experimentally with a floor-mounted unit, the “Task Air Module” (TAM). All three provide some individual control of cooling, while PEM and CDESK also provide individual control of heating.

During the experiments and under the experimental conditions, displacement ventilation with air outlets close to floor level were found to produce the lowest concentrations of hazardous substances and aerosols in the working areas of kitchen appliances when compared with mixed or displacement ventilation through ceiling outlets. Displacement ventilation with low-induction ceiling outlets achieved better results than mixed ventilation.

Recent years have brought the popularity of methods in which neutral networks are applied. They seem of particular importance while dealing with diagnosing, predicting and estimating. Those methods rely on collected data base, simulation and interpolation in the so-called learning process. There are attempts at neutral network application in building engineering. The paper sums up the initial phase of research on neural applications in the air exchange estimation.

To evaluate the performance of a ventilation system, the local mean age of air has usually been used to estimate how efficiently fresh air is diffused to a desired location. However, this index alone is often not sufficient to assess the local air quality that is also associated with the property of the contaminant source in a ventilated space. Several new indices have been proposed recently, which enable the use of numerical simulation and appear to be appropriate scales for assessing mixing ventilation systems.

The effectiveness of ventilation related to the two primary tasks of ventilation, (I) the supply of fresh air, and (ii) removal of contaminants, is investigated. To allow a quantitative description of ventilation performance, several effectiveness numbers are discussed, and their dependence on air flow characteristics is explained. The effectiveness of displacement ventilation regarding renewal of the internal air population is analysed both experimentally and by means of Computation Fluid Dynamics simulations.

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.

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.

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.