Design solutions for naturally ventilated houses in a hot humid region with reference to particulate matter and noise reduction
Pollution in developing countries is generally much worse than in developed countries, and is caused by the widespread use of poor quality machines both industrial and in motor vehicles. Obviously, motorised vehicles are a major source of today's pollution. Motor vehicle emissions, whether gases, particulate matter or noise, can all be dangerous. Particulate matter, especially very fine particulates, is the major concern of this thesis, which considers their capacity for penetrating deep into the lungs and developing slowly to cause noticeable illnesses. Low-income people who live within the city centre are the most exposed to traffic pollution whether on the move or indoors. Low cost housing, whether self built or provided by government or private sectors, often exposes occupants to both lack of thermal comfort and pollutant intrusion from adjacent street traffic. Houses in warm-humid regions depend on large openings and through ventilation for thermal comfort. Openings allow air pollution and noise to penetrate these houses easily, thereby affecting the health, comfort and well-being of residents. Closing all openings and changing from natural ventilation to air conditioning is not however a practical solution for low cost housing. This study explores the effect of boundary fences, vegetation, and detailed opening design in reducing the penetration of airborne particulates and noise into the living spaces of typical low-cost urban houses. The experiments carried out for this study include computational simulation, manual calculation and field experiments. The research indicated that there are feasible and practical solutions to the reduction of fine particulate matter and street noise in such housing by using solid and massive barriers combined with vegetation and a specific window type. Solid and massive barriers were constructed to slow the progress of the pollutants by reduction of wind speeds on approaching obstructions. If the wind slows down enough, this effectively 'holds' the pollutant in place. In this case, the deposition surface was provided by vegetation with dense foliage. The surface of the vegetation was predicted to deposit particulate matter effectively, which would then be washed away naturally by rains. Some types of leaves were studied to find the relationship between the physical characteristics of leaf surfaces and their ability to deposit particulate matter. Before entering the living spaces, the particulate matter then encounters further obstruction by jalousie windows thus reducing its concentration. The solid and massive fence also created an acoustic shadow and noise was then further reduced by the jalousie windows. The resulting indoor noise level was found to be closer to the proposed Indonesian standards of 45 dBA.