ZEMCH 2015 - International Conference Proceedings | Page 411
Daylight Factors and Shading:
Daylighting has been incorporated in all building designs and was evaluated using Autodesk Ecotect Analysis. Daylighting is considered important factor when it comes to environmental design.
However, in the selected case study, sunlight can be excessive, and therefore, the design should
be evaluated carefully considering most site analysis, since Abu Dhabi average temperature can
reach above 38 degrees Celsius in summer. Daylight factor is affected by the size of the window
and the placement in the facade and its direction.
According to Brown and Dekay (2001:30), there are two approaches into solving daylighting in
clear skies; either by decreasing the size of the window or using a modest size of a window but
shaded from direct sunlight. Proper shading was installed according to the location and the function of the space to prevent direct solar heat gains during summer and reducing cooling loads
throughout the year. As stated by Brown (1985:72), daylighting in hot climates during clear sky
conditions and bright sun involve finding ways to use the light while excluding as much solar
heat gains as possible from the building and open spaces.
The first strategy was to analyze the daylight factors and shading. The evaluation was carried out
using one of the prime villas that has an optimal location being on the tip end of the block facing
the direct radiation of the sun path. The courtyard in the villa and the open spaces in the pocket
blocks are not utilized sustainably. Brown (1985:79) proposed that buildings and open spaces can
be organized in a way to preserve each building’s access to breeze and act as shading using its
building height. Benefiting from the central location to bring in natural ventilation is a key strategy. The first analysis was on the courtyard showing the direct sun in summer season. The daylight
factor range reached 63-83 percent before the courtyard was shaded. The bright yellowish color
in the legend (Fig.16) indicates that the daylight factor is beyond exposed and need to be examined for better insulation or a shading mechanism. To shade the entire courtyard would defeat its
purpose.
The courtyard is a private area where the family can unwind inside of their house, exposed to the
sky without worrying about clothing, and activity. Semi-covering the courtyard is more efficient
and can allow access to diffused sunlight and natural ventilation through the designated area.
After the shading, the value range dropped significantly to 54-74 percent. Figure 16 shows the
colored area drop to a maroon shade amplifying success.
Figure 16: Courtyard before and after shading
Sustainability in nature: lessons for yas island housing communit y in Abu Dhabi
409