Determining Ventilation Orientated Optimum Window Size for Urban centers of Ethiopia
No Thumbnail Available
Date
2020-11
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa university
Abstract
Natural Ventilation is an effective method for passive cooling, increase indoor air quality
and minimize energy consumption of a building. Natural ventilation through
window openings is an effective solution to bring air into internal spaces and
improve indoor environmental condition. In urban centers, where the density is high
and local wind is reduced, the geometry of a building and its opening has a
massive role in natural ventilation. The current building codes and regulations of
Ethiopia miss detailed guidelines for natural ventilation. On the code and regulation
for windows are specified only in relation to the floor area regardless of orientation,
height, location and climate. Since the country has different climate zone in different
regions, the generalized building code and standard will lead to over or under ventilated
rooms in both scenarios creates discomfort. The study attempt to determine
ventilation-based window size for urban centers of Ethiopia on different façade
orientation to increase the effectiveness of natural ventilation. As wind is the main
driving force of natural ventilation, regionalizing of Ethiopia according to wind speed
and wind direction (secondary-Inter cardinal direction) is presented in order to
study the potential of natural ventilation at different regions in the country. The
average wind speed is categorized using the Beaufort’s scale of wind speed. The data
addresses the urban centers of Ethiopia and the urban centers are selected by density.
Both scenarios (single side ventilation and cross-ventilation) are discussed in each
zone. Appropriate opening size is determined, using the window orientation with
respect to the wind flow direction and also best and worst window orientation is
illustrated for each zone. The study verified that, the effectiveness of natural ventilation is
associated with wind zone where the urban centers are located.
Description
Keywords
Natural ventilation,, window size,, window orientation,, wind map