English

A method based on both measurements and questionnaire has been developed to investigate comfort in office buildings. The measurements apparatus records temperature, humidity, noise, light, odours and occupant's perceived comfort. The questionnaire contains information about indoor climate and working environment. Results are given and analysed for 60 offices in France.

The impact on thermal comfort of the way of introducing replacement air (to replace air being exhausted by the hood) in a kitchen was analysed using mathematical models and laboratory experiments with a tyhermal mannequin. Results allow to rank systems for replacement air introduction from the most to the least tolerable : displacement ventilation, mixing ventilation with ceiling air diffusers, front-face discharge and backdrop plenum.

The aim of this study is to investigate an optimal air-conditioning adjustment for an indoor space where people come in and out. The authors conducted the experiments by measuring the physiological and psychological responses of subjects who walked outdoors and then entered a chamber. Psychological responses to summer climate were grouped within three categories of: "cool" - "comfortable," "hot" - "uncomfortable," and "cold" - "uncomfortable." These responses are related with subjects perspiration.

96 human subjects (18 years age students from a Swedish high school) were submitted in an experimental room furnished as a classroom to different air flows issued from different ventilation systems : displacement with constant air flow rate, alternating between displacement (floor diffusers) and mixing ventilation (ceiling diffusers) with constant flow rate, mixing ventilation with varying flow rate, displacement with constant flow rate and with ceiling fans to generate air motions alternatively on and off.

This study describes the development of a three dimensional (3D) Lagrangian code of particle transport in indoor turbulent flows. This approach consists of integrating transport equations for each particle at each time step to determine successive positions of the particle. The first challenge was to calculate instantaneous velocities of the airflow. The mean component of these velocities was calculated by a classic CFD code. A stochastic process based on the Gosman and Ioannides method generated the fluctuating component. Corrections were applied to better fit experimental results.

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.