Investigation of the Ventilation Rate around Different Urban Morphological Property Types: High Rise -Vs- Low Rise in Bangkok’s High Density Areas

Abstract

As a consequence of city development and increased urbanization, Bangkok, the capital of Thailand, has experienced serious air pollution problems in high density areas over the past several decades, especially at pedestrian-level (at 1.5 meter level above ground) between groups of buildings in the city’s central block. As we all know that urban settings have a direct impact on the urban air flow. Lack of research because urban morphology (Greek morphé : shape) is too complicated to do air flow simulation. The objective of this study is to find the relationship between urban high-rise and low-rise morphology properties and urban air ventilation in high density areas of Inner Bangkok. The methodology involves an investigation using computer fluid dynamics (CFD) simulation. The results based on air change rate. Main findings of this paper are as follows; Urban high rise- high density areas has better ventilation rates than low rise- high density areas in all cases. The ventilation rate from high to low are as followings, 1) urban high rise- high density are block number 80, 17 and 65 and ACH is 26.23646, 25.63358, 12.77694 2) urban low-rise- high density are blocks 24, 30 and 26 and ACH is 11.72196, 11.19111, 5.769723, respectively. The conclusion of this research is the most influential variable factors is the height of the building. Blog orientation and open space in the city block.