This paper presents a study aimed at evaluating the effectiveness of natural ventilation strategies used in government dwellings in the Egyptian desert climatic design region. Three government housing blocks, built in the New Al-Minya city, were employed as case studies. Autodesk-Ecotect and FloVent CFD software were used to simulate the internal air movement and air temperatures. Theoretical analysis shows that there is considerable cooling potential by natural ventilation, with the thermal comfort potential being improved by up to 52% peak and 33.5% average.

Natural ventilation is a well known strategy to improve indoor air velocity and reduce indoor temperature. It is the main criterion to achieve thermal comfort in terraced housing in Malaysia. In hot and humid climates, one drawback to single sided ventilation is that the wind effect is not well captured, which in turn, increases the use of mechanical cooling. Therefore, it is important to understand and consider the use of the solar chimney as a stack induced ventilation strategy for a single sided ventilated room.

The identification of effective factors in the historical formation of architecture can help develop architecture and its various aspects (Mofidi, 2005). These factors may be classified in the groups of cultural, historical and climatic. Specifically, the application of the native and traditional basis of past architecture can be highly significant for the improvement of contemporary architecture (Fathy, 1986).

It is only comparatively recently, since the development of mechanical ventilation and refrigeration, that it has become possible to completely control the air quality and thermal environment inside buildings, irrespective of outdoor conditions. However, such control is an energy intensive process that requires reliable energy supply. Concerns about future security of conventional supply, combined with the impact of fossil fuel emissions on global warming, has resulted in renewed emphasis on building energy efficiency.

The reduction of carbon dioxide emission due to energy consumption in the household sector is an urgent task, worldwide. As a measure to respond to the task, a new regulation has just been enforced since April 2009, in Japan. This regulation evaluates the energy performance of detached houses by estimating the primary energy consumption for different uses, namely, heating, cooling, ventilation, domestic hot water and lighting.

The prediction of indoor airflow is indispensable in evaluating the thermal sensation of occupants in a cross-ventilated space because enhanced heat loss due to the elevated convective heat transfer in the occupied zone is an essential part of improving thermal comfort. A domain decomposition technique was developed to separate CFD for internal cross-ventilation flow from external flow outside buildings, and to predict indoor airflow with reasonable computational effort and sufficient accuracy.

An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured.

A working group for natural ventilation and cross-ventilation at the Architectural Institute of Japan (AIJ) was established in 2005 by researchers and designers with an interest in this topic. One of the tasks of the working group is to review and classify related research papers. This paper introduces the activities of the working group and presents some results of the review work.

Designing for natural ventilation became permissible across an extended range of climate zones in 2004 with the incorporation of an adaptive model into ASHRAE's comfort standard (ASHRAE, 2004). This mainstreaming of adaptive comfort was further reinforced with the introduction in 2007 of a European standard (EN, 2007) that mirrored ASHRAE's precedent. Despite broad international acceptance and application of the concept, there remains a gap in the fundamental theoretical underpinnings of the adaptive comfort approach.

A simulation study on the reduction of cooling loads by utilizing cross-ventilation was performed for a typically shaped house as defined by the Architectural Institute of Japan. A reduction in cooling load of around 50% could be achieved when the windows were opened liberally at night compared with the cooling load when all the windows remained closed, regardless of building coverage ratio.