Although most of the apartments adopt state-of-the-art convenience facilities, since they have become the most popular housing type in Korea, they depend on natural ventilation for HVAC systems, as traditional floor heating systems (Ondol) are used. On the other hand, the indoor environments of the apartments have become more important, because people stay longer in a room and the room environment is polluted, because of various kinds of interior materials. Accordingly, some apartments apply air conditioning systems using AHU and ventilation systems using heat exchangers.

This paper describes the hybrid ventilation system of a new office building (650 employees) in Amsterdam (The Netherlands) equipped with a decentralized building automation and individual controls.

The paper presents the effects of airflow access points on the passive modification of indoor air temperature in a partly roofed high-mass courtyard building found in moderate climate of southeast Queensland. Results of a field investigation reveal that despite sufficient shading within the courtyard, its air temperature and thus comfort levels depend greatly on the location of airflow access points in the building layout and section.

Increasingly, European building designers have used natural ventilation to control air quality and cool commercial buildings to conserve energy compared to mechanical cooling and fan operation. These advanced natural and hybrid ventilation systems may be adapted to the North American context, but work is needed including consideration of the broader diversity of climates. An approach to the analysis of climate suitability is presented and applied to a number of North American climates.

This study presents a comparison of perceived indoor conditions in both air-conditioned and naturally ventilated buildings.

As part of a graduation research, six case studies were carried out to assess the validity of 10 often heard assumed disadvantages of natural ventilation in offices, including poor IAQ and thermal discomfort. The case studies included a methodic comparison of six buildings based on literature, interviews, field measurements and re-analysis of reports by others. Thus the preconditions for natural ventilation of office buildings and the most important design features could be determined in order to meet the performance standards as in use in the Netherlands.

A design procedure of material and hybrid ventilation systems is described. It includes a climate suitability analysis, a loop equation design method and a detailed multizone coupled thermal-airflow analysis using CONTAM97R software.

The potential for natural ventilation is the rating of the possibility to achieve a good indoor air quality by natural ventilation only. The potential for passive cooling can also be defined. These potentials depend on site and building and are based on several parameters. Example of determination in Geneva area is given.

Three portable air cleaners alone or combined with ultra-violet germicidal irradiations were tested to determine their capacity to remove airborne bacteria. Results give values of airborne bacteria removal rates.

The impact of an ozone generator air cleaner was investigated in a full scale test chamber. Test results demonstrate that, where styrene is present, air cleaners increase indoor levels of formaldehyde, oxygentaed organic compounds, ozone and nitrogen dioxide.