QUANTIFYING NOISE EXPOSURE AND NATURAL VENTILATION PERFORMANCE IN URBAN AREAS

QUANTIFYING NOISE EXPOSURE AND NATURAL
VENTILATION PERFORMANCE IN URBAN AREAS
M Barclay University of Wales Trinity Saint David, Swansea.
S Sharples University of Liverpool
J Kang University of Shefeld
1 INTRODUCTION
Natural ventilation strategies are difcult to implement for buildings in urban areas for a number of
reasons, such as lower wind speeds, higher temperatures due to the urban heat island effect,
pollution and noise. This paper deals with how noise and ventilation performance can be quantied.
The easiest way to achieve the least restriction of a ventilation path is to open large areas of the
facade-2. This leads to the conict between attempts to reduce noise ingress and the maximizing of
natural ventilation rates.
Quantifying these sometimes competing factors with information and tools that are appropriate to
building design professionals should help improve design decisions. The information and tools
presented in this paper involve a number of different scales. These have the aim of integrating and
comparing different environmental factors affecting natural ventilation. These scales are both spatial
and temporal. Different calculation methodologies have to be used for different scales as different
physical processes and relationships are important, and also the requirements for accuracy differ.
The linking of these different scales is necessary and is the main contribution presented in this
paper. An example of the smallest scale considered Involves the nite element model of the
ventilation aperture and the largest scale deals with the mapping of noise around an urban area.
The same consideration of scales is important for the natural ventilation calculations, with different
approaches being used to represent the driving forces of the weather, the air ow around a building
or urban area and airow through an opening or across a number of building zones/rooms.
This paper gives an overview of a method to quantify the relationships between noise exposure and
natural ventilation performance in urban areas. The energy consequences of trading off reduced
natural ventilation cooling against acceptable noise levels in buildings are also considered. The aim
of the research was to determine where noise reduction technologies would have the most
signicant impact in terms of enhancing natural ventilation potential in urban areas. More details of
this approach and more example results can be found in the thesis of one of the authors?