An Experimental Study on the Effect of Surface Orientation and Inclination on Incident Solar Irradiation: Application to Buildings

The study explores the impact of surface orientation and tilt on incident solar irradiation. It was conducted in M'Sila, an Algerian province, from February to June. A number of experiments were carried out using an experimental setup consisting of a heliometer and a slant changer, which allowed for the variation of the tilt angle. Nineteen tilt angles ranging from 0° to 90° were investigated for the four main directions: North, South, East, and West. The obtained outcomes were statistically analyzed. At east and south orientations, incident solar irradiance rose as a function of tilt angle, reaching a maximum at the optimal angle, and then gradually decreased. Generally, the incident solar irradiance decreased as the tilt angle increased in the case of west and north orientations. The tilt angle of the exposed surface as well as the sun's elevation in the sky affected the amount of intercepted energy significantly at each orientation (p<0.05). When the sun was low in the sky, the south orientation was most preferred for an inclination greater than or equal to 25°. The north-facing surfaces with steep slopes (β³ 55°) received the least amount of solar radiation. These results hold great importance, particularly in the building sector, as they can be utilized to achieve energy saving.