A simplified tool, called ConsoClim, has been developed for estimating energy consumption of air conditioned buildings and for comparing HVAC and building solutions. Its main aim is to be used at the early stage of the design process. It means that algorithms have been developed to be used with minimum and quite simple inputs that are available in manufacturers' catalogues or can be fixed at typical default values. The aim is to check that building design options and HVAC system choices lead together to an efficient global energy performance.

In the Mediterranean countries, where the active solutions of air-conditioning must be avoided, natural ventilation allows improvement of indoor comfort which is generally critical in hot season, and reduction of building cooling loads.A three-dimensional zonal model for calculating temperature fields and airflow distributions insideunconditioned buildings was developed.

Ventilation determines the indoor air quality and has a profound effect on the energy consumption and thermal (summer) comfort of buildings. Simulation of natural ventilation leads to the prediction and evaluation of these performances.Coupling ventilation network and thermal simulation models is necessary to simulate natural ventilation as the mass and energy balance are physically linked in a naturally ventilated building. Several ways of coupling exist, each having its own possibilities and difficulties.

The present work is part of a research effort aimed at integrating a detailed model of airflow in large spaces with an algebraic multizone infiltration model to describe pollutant transport and coupled air flows within and between complex buildings and large spaces. In the past 15 years, zonal models were developed with the goal to obtain an approximate prediction of airflow characteristics in large indoor spaces. Also, reducing the number of grids in CFD models is a natural way of decreasing their demand of computational resources to solve air flows in room.

Through the analysis of the main international environmental performance rating systems (BREEAM, LEED and GBTool) this work aims to show international design tendencies concerning sustainable building equipment requirements and to provide to designers and researchers a broad view of sustainable building equipment solutions. Hence a particular attention was paid to the assessment approach provided by these systems for each requirement, focussing on the comparison of the building performance to a benchmark, on compliance with qualitative indications or use of best technologies.

Through the analysis of the main international environmental performance rating systems (BREEAM, LEED and GBTool) this work aims to show international design tendencies concerning sustainable building equipment requirements and to provide to designers and researchers a broad view of sustainable building equipment solutions. Hence a particular attention was paid to the assessment approach provided by these systems for each requirement, focussing on comparison of the building performance to a benchmark, compliance with qualitative indications or use of best technologies.

Purpose of this study is establishment of energy efficient natural ventilation system for Japanese conventional wooden single-family house, by using humidity-controlled extract units (code name: GHN).To evaluate the effect on energy performance and indoor air quality by adapting the GHN to the passive stack ventilation system, airflow rate, humidity, temperature and CO2 concentration are measured over a period of one year in an experimental house.

Within the program "Solar Optimized Buildings" which is funded by the German Ministry of Economy (BMWi), a building for the DB Netz AG has been realized and monitored. The design concept of the building is dominated by architectural solutions for ventilation, cooling and lighting of the office rooms. Due to the change of responsibilities during the design and building process, the targeted primary energy consumption of 100 kWh/m 2 y has been exceeded so far. The reasons lie primarily in the inadequate operation of the technical systems for heating, ventilation and artificial lighting.

This paper describes work currently being carried out to evaluate the environmental impact and energy savings potential from the application of passive ventilation cooling in urban buildings. The work is carried out as part of an ALTENER project focussing on solar and passive ventilation for urban buildings. The study involves the collection of information for current building stock in four European countries; UK, France, Spain and Greece.

The natural ventilation potential (NVP) is the possibility, or probability, to ensure anacceptable indoor air quality by natural ventilation only. A passive cooling potential (PCP)can also be defined, as the possibility to ensure an acceptable indoor thermal comfort usingnatural ventilation.