Investigating of the light shelf system performance in the main four geographical directions in hot arid zone : a case study of a hypothetical office building in New Cairo area

الملخص EN

Hot arid climates are characterized by clear sunny sky most o f the year.

S uch c limates are known for their futility to use light shelves, especially in terms of energy consumption and visual performance.

This requires more studies to be conducted in order to explore the factual possibility of benefiting from the effective use of light shelf and quality in hot arid climate.

Therefore, this paper performs investigation into using different light shelf positions for the four main geographical directions.

This system will be evaluated from the point of view of its impact and influence on special daylight autonomy (sDA) 300/50% [% of Space Area]), Annual sunlight Exposer (ASE 250 h/1000 [% of Space Area]), daylight availability (partially daylight, daylight and over lit), and Total Annual Energy consumption (tAEC [KW/m2]).

The study performed a parametric analysis using DIVA for Rhino (grasshopper) simulation tool on a hypothetical office building in New Cairo area.

The study outcome proved that light shelf can be an effective daylighting system to improve lighting environments without any negative effect on energy consumption, especially by using that kind of combined light shelf (internal and external).

The results show that the performance rate in descending order was in the south, then west and east while it is not futile of use horizontal light shelf in the north direction.

Therefore, on this basis this search recommends developing a parametric design for light shelf systems.