English

This paper presents the investigation results on a simulation program, which calculates the particle trajectory under different airflow patterns in the multi-zones structure building. The numerical simulation is first used to predict airflow pattern and ventilation performance. Then, the particle movement is determined by employing Lagrangian method. The simulation identifies the characteristics of ventilation and indoor air quality.

The study presented in this article concerns the numerical simulation of airflows and occupational exposure to household contaminants. A finite volume code (CFD) is used to simulate a single-family house with several ventilation, heating, and climatic conditions. The concentration and occupational exposure levels of household contaminants CO2, CO, HCHO, NO2, and water vapour, all from human metabolism, along with those from gas cooking and smoking, are evaluated over a day for a generic occupational schedule of four family members.

Measurements of indoor air quality indicators (temperature, humidity, dust, biocontaminants and CO2) were performed monthly during one year in a French office building. Air filters of the air handling unit of the building have also been characterised on site and in laboratory. Detailed results of these measurements are given and analysed.

The effects of an air conditioning system for office buildings were studied experimentally and computationally. A displacement ventilation system was used as the main air-conditioning system, and a partition with a built-in circular fan was used to deliver the air-conditioned clean air near the floor supplied by the main displacement system to the occupant in the office directly.

This contribution reports on investigations about the performance of decentralised ventilation units with heat recovery. Such units can be easily installed in individual rooms and therefore offer an interesting alternative to central ventilation units. Nevertheless these units exhibit some problems. Experimental examinations of two commercial decentralised units showed that the real effectiveness of heat recovery was always below 50 % and that considerable leakage between the air ducts can result in poor indoor air quality.

This paper proposes a new personal air-conditioning system, which modifies a common partition used in offices to a partition-type fan-coil unit (PFCU) with inlets and outlets on its surfaces. Chilled water is supplied as the cooling energy, and is delivered to the partitions by pipelines incorporated into the structure. Hence, conventional air conditioning systems using ceiling-based air diffusers for open-plan offices may be dispatched into several small individual systems controlled by the occupants.

This study compares indoor climate, cooling efficiency and energy consumption of an underfloor air distribution system and a ceiling-based system in a test chamber. Floor-based system appears to provide better thermal conditions with lower electricity consumption.

This paper proposes a new mode of ventilation for indoor airflow. Computational results show that with properly designed supplied air velocity and volume, locations of diffusers and exhausts, the proposed system should be able to maintain better thermal comfort with a smaller temperature difference between the head and foot level, and possibly lower energy consumption, if compared with conventional systems. It looks promising that better indoor air quality (IAQ) in the breathing zone could also be achieved but that further work is needed to determine if IAQ benefits are significant.

CFD calculations were used to compare temperature and air velocities in an environmental chamber equipped either with a conventional comfort overhead air supply system or with an underfloor supply system. Results show the advantages of underfloor system to provide adequate temperature, velocities and turbulence in the seated zone.

The purpose of this study is to clarify the usefulness of a displacement ventilation air-conditioning system introduced into a multipurpose hall after CFD simulation and measurement. In the multipurpose hall of Kurume City, a displacement ventilation air-conditioning system equipped with a floor outlet had been adopted. A CFD simulation for the purpose of selecting an air condition system indicated the floor outlet system would be more effective for the design plan of the hall than a ceiling outlet system.