Evaluation of Window-Blind’s Effectiveness on Reducing Total Energy Consumption of a Library Building for Different Slat Angles

Abstract

Modern buildings have a high percentage of glass surfaces, which increases the amount of solar radiation that enters the structure and increases energy demand and discomfort for occupants. Consequently, the use of window shading devices is becoming more important than ever. This paper evaluates the effectiveness of blinds applied on a library building located in Errachidia region. The building is simulated in Designbuilder simulation programs during summer period (starting from 1st May to 31st August), with and without shading devices, for different blind slat angles varying from 10° to 170° with a step of 10°. The calculated total energy consumption concerns cooling and lighting. The comparison of total energy loads with and without blinds demonstrates that the use of window blinds optimized the total energy consumption by 17% for angles 10 and 170, and 10% as a minimum optimization percentage (angles from 70 to 120). This optimization leads to an economy of about 5800 DH during just four months (considering 0.951 DH/kWh). It can be concluded that the adoption of shading devices in buildings with a high percentage of glass surfaces (25% in our case study), is very useful for energy consumption management and energy conservation, especially in the 6th thermal Moroccan zone, where our building is located.