TRAFFIC AND AIRFLOW NOISE LEVEL PREDICTIONS FOR BUILDINGS WITH NATURAL VENTILATION IN URBAN ENVIRONMENTS

Open Access
Author:
Kim, Moon Keun
Graduate Program:
Architectural Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
None
Committee Members:
  • Jelena Srebric, Thesis Advisor
Keywords:
  • urban area
  • air flow noise
  • traffic noise
  • natural ventilation
Abstract:
This research aims to identify optimal design strategies for natural ventilation systems in order to predict traffic and air flow noise level in indoor environments set in urban settlements. Natural ventilation systems can utilize outdoor air in order to improve the quality of the indoor environment as well as to reduce energy consumption. However, natural ventilation systems create acoustic problems if a building is in an urban area. For instance, if windows are opened for natural ventilation high levels of traffic noise or high wind driven air pressure through windows can interrupt people working in the building. Much research has been done to study traffic noise prediction methods in calculating the sound attenuation during propagation outdoors based on ISO (International Organization for Standardization) 9613; however, this research introduces a method combining outdoor sound propagation with indoor sound transmission based on ISO Acoustic Standards. This study to predict background noise level in a building for natural ventilation can be categorized into two specific areas: (1) traffic noise and (2) air flow noise. Traffic noise is designed by CoRTN (Calculation of Road Traffic Noise, U.K) algorithm and FHWA TNM (Federal Highway Administration Traffic Noise Model, 2007) models. The project will use numerical calculations to determine traffic noise values including the effects of sound attenuation, transmission and building façade. After controlling building façade design, targets of ventilation, outdoor weather conditions and traffic noise attenuation are specified for these design solutions. The air flow noise is generated by an opening in naturally ventilated building. The pressure difference by wind driven and stack effects of an opening determine air flow rate. Therefore, this research identifies airflow noise related by the pressure difference and air flow rate. The results of these simulations indicated that natural ventilation systems succeeded not only in predicting environmental traffic noise, but also in providing optimum wind driven air pressure. Finally, the results should compare numerical simulations and real measurements with natural ventilation while providing acoustic comfort for building occupants in urban areas.