In designing thermal and ventilation systems in buildings, an examining process of exchange between the designers and analysts is needed. This study aims to expand the simulation system of thermal and ventilation into an automated process for the design of optimum thermal and ventilative conditions, based on the expertise of analysts, the analysis of the thermal environment and the modification of the design, by automating these functions.

Since the beginning of this decade, natural ventilation in office buildings is receiving specific interest. There are two sorts of application. Natural ventilation can be a strategy for indoor air quality control. Besides it can be used as night ventilation during warm or hot periods. In this case the objective is to cool down the thermal mass and improve the thermal summer comfort. The EC JOULE NatVent project wanted to identify the barriers to the application of natural ventilation in office-type buildings in moderate and cold climates and to provide solutions.

Ventilation is essential for the maintenance of good indoor air quality, although there is evidence to suggest that energy loss through uncontrolled or unnecessary air infiltration is excessive. In this study, estimates are presented for air change (ventilation and infiltration) energy use in non-industrial buildings for 13 countries. Various methods are used for the estimates, but they are mainly based on calculating the total annual enthalpy change needed for the conditioning of air. The potential for reduced energy use by improved ventilation control is also briefly reviewed.

The overall objective of the present work is to evaluate the performance of three turbulence models, with a view to predicting characteristics of airflow within an anisothermic cavity. The standard K-c. model, the Renormalisation Group model (RNG) and the Reynolds stress model (RSM) are used in conjunction with the Fluent code. The accuracy and the relative performance of the three models are evaluated by comparing their numerical results with experimentally obtained data. This comparison is made for the constant flow rate of a twodimensional turbulent mixed convective airflow.

Low energy buildings should satisfied two main tasks: to assure a low energy use and provide an excellent residence comfort. The building envelopment elements, especially the transparent one, have major influence on both tasks. The paper presents research results of heat transfer and fluid flows through double pane window with tight, opaque insulation screen. The insulation screen was installed in such a way, that a semi open air gap was formed. An air gap is connected with the building interior through an opening on the bottom and with exterior through siphon at the top.

Achieving optimized partial improvements of the indoor climate may often be better than to know all optimal levels. The purpose of this study was to investigate the relative importance of temperature, noise, draft and window area. 30 heat-acclimatized subjects participated in 10 exposures in single person climate chambers. Each exposure lasted three hours. During an exposure, the subject was free to optimize the operative temperature at a link to either draft, noise or window area. For each pair of parameters, three linear links were tested.

The acoustic environment was examined in an office building with a high prevalence of symptoms typical of the sick building syndrome (SBS). Levels of ventilation noise exceeded 70 dB in many rooms. The peak was often found in the region below 20 Hz, which is the infrasound region and generally regarded as inaudible at these levels. Symptoms attributed to exposure to low frequencies include nausea, headache, choking, coughing, visual blurring and fatigue, which appear to overlap with some of the symptoms of SBS.

The present study applies the N3S CFD code to the air cooling simulation on an "architectural reference object", namely the "Maison Ronde" of Mario Botta. The summer night situation is examined when natural ventilation creates indoor air motion and cools the building structure. The transient behavior of the walls is represented by a thermal model coupled with the CFD code. The simulation evaluates the unsteady temperatures of the outdoor and indoor air flow together with those of the wall surfaces.

Air conditioning is widely used in the office building sector in the French Mediterranean region. Though often a «sine qua non» for renting office space, there is however a widespread feeling that operating and maintaining air-conditioning systems can be troublesome (unreliability, regulation and maintenance difficulties, non uniform comfort conditions, high prices are frequently lamented).

This paper examines historical data on Government expenditure on grants for home energy efficiency improvements, and the effect that this had on the uptake of insulation measures. The analysis focuses on loft insulation, this being the main measure that has been targeted by grant schemes. The paper shows that variations in loft insulation uptake between 197 4 and 1996 were closely tied to changes to grant schemes. Furthermore, there is a clear correlation between the uptake rate achieved and the level of funding provided by the Government.