Selection of slat separation-to-width ratio of brise-soleil shading considering energy savings, CO2 emissions and visual comfort - a case study in Qatar

The selection of slat separation-to-width ratio should ensure total blockage of beam solar radiation. Consequently, the sun altitude determines the ratio that yields no discomfort glare; due to the country's latitude, this ratio has to be less than unity in south orientations and slightly larger than the sine of the slat inclination angle in east orientations. The proper selection of separation-to-width ratio leads to significant energy savings which, if integrated with lighting control for internal electric lights, may reach 39.5% and 36.6% in south and east-oriented Clear glazed façade offices, respectively. For a country with high greenhouse gas emissions, this simple energy-conservation measure also provides a cheap technique that is able to reduce CO2 emissions by up to 52.7 kg/m2/year.