Design guidelines for natural ventilation in buildings normally focus on the potential hourly air change (ACH) rates based on the building space parameters. Critically, external airflow design data is often assumed on the basis of a single mean wind speed and an associated prevailing wind direction. This can result in significant variation in ventilation rates and comfort conditions when non-design external wind conditions prevail.

This paper describes the possibility of high-temperature radiative cooling combined with natural ventilation. Weset uptwo small wooden experimental buildings:onehas a radiative-cooling system on the ceiling;and the other hasa conventional convective-cooling system.In the room with radiative cooling, we examinedthree patterns of cooling and ventilation: the first is radiative cooling withoutventilation; the second is radiative cooling with natural ventilation; and the third is no radiative cooling but natural ventilation.

Field survey on indoor air quality was conducted during winter season, in an elementary school at Kagoshima city. Asthe windows had been closed because of avoidingthe cold outdoor airIn thewinter,CO2 concen- trationsunder pupilsstaying in the classroom wereover1500 ppmat the end of the lesson. When the windows of the corridor facing outside had been open, the CO2 concentrations in corridor were close to the outdoor CO2 concentrations. It was found that the ventilation during the break could play an important role in CO2 concentrations during the next lesson.

The growing energy consumption for cooling of buildingsis one important concern in Mediterranean countries.Natural ventilation plays an important role as passive energy saving strategy, regarding cooling of buildings in this climate. Solar chimneys are some of the most useful systems that make use of this strategy. But optimised implementation and quantification of the improvements achieved by these systems are required and must be assisted by a comprehensive thermal characterisationof them. However the performance of solarchimneys depends on combined and very complex physical phenomena.

This study examines air quality measured in two classroomsin a UK school, which uses two different forms of natural ventilation, over an eight month period. The first classroom is an internal room that contains a top-down natural ventilation system known as a Windcatcher.The room also has a separate mechanical extract fan. The second classroom is ventilated using windows and doors that open to the outside. This study focuses on measuring the performance of a Windcatcher and reviews its potential to replace ventilation provided by conventional windows.

In Part 1, the changes in wind pressure coefficient distributionon the surfaces of the buildings when building coverage is varied are evaluated and identified, and it is elucidated that the ventilation through skylight is effectivebecause the surfacepressure can bekept negativeon roof surfaces even when building coverage is high.In Part 2, the results of numerical simulation (CFD) are compared with the experimental results.

In Korea, all residential buildings adopt floor- heating systems for indoor thermal comfort. And the ratio of multi-family houses exceeds 50%. Lately problems of noise between floors and contamination of indoor air in multi-family houses emerged as social issue, and performance standards related to noise between floors and ventilation were established in Housing Regulation. Concerning these issues, many systems have been developed.

In mild climates due to the increase of request of comfortof people there is a growing number of installation of low cost and low efficient cooling system even in new buildings. In designing low energy buildings it necessary nowadays to consider this trend and offer proper solution (envelope and plants) able to reduce the consumption of primary energy.

Goal of the study was to investigate the relation betweenthe level of ventilation and the performance of school children in classroomsIn one school in two classrooms the same ventilation system was installed. The two classrooms were located at the same faade. The system had a possibility of supplyingfull outside air to the classroom or the position with full recirculation of air.

Considering that natural ventilation is a climatic factor,a renewable alternative, as well as an important source of comfort, it seems to be relevant to consider its great potential when applied to architecture, taking into account economical and environmental gains. It is difficult to think about studying air circulation without mentioning the north Africa vernacular architecture and its ability to create the best solutions to increase the ventilation without any energy consumption, therefore, adopting passive cooling.