The basic mechanism for natural ventilation in a building involves air flowing through purpose-made ventilator openings. These ventilators must be carefully designed as natural ventilation driving forces are weak compared to the dynamic forces created by mechanical systems. This paper describes a series of experimental parametric studies that investigated how components within a ventilator (in this case louvers and wire mesh screens) interacted. Airflow measurements through the individual louver and mesh components were compared to the airflow through mesh / louver combinations.
This study was aimed to analyse the ventilation efficiency and indoor air quality in the conventional kitchens, when porous screens were installed on the transoms. Numerical simulations and laboratory full-scale experiments were carried out in the model kitchen in the Department of Architecture at National Cheng-Kung University. The influences of porous screens on the temperature fields, flow structures and ventilation rates were indicated. The "Tracer-gas Concentration Decay" method was conducted to measure the air exchange rate and the age of air in the model kitchen.
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.
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.