Book - School of Science and Technology

18070 The building in summerinformation is more easily understood by inspection of a diagram such as that shown inFigure 3.3, for a latitude of 50 north. In this example, the position of the sun has beencomputer plotted from sunrise to sunset on three discrete dates, against a background ofaltitude and azimuth. Similar profiles for other latitudes may be constructed and standardversions are available, if required, in the form of overlays.*When a miniature plan of a building, correctly orientated, is placed at the centre of adiagram such as this, it is then possible to visualize the likely peak incidence of solarradiation on the various faces throughout the daylight hours of a chosen month. It will beclear that easterly faces will be subjected to solar influence first, followed by the south eastand south, by which time the east face will be going into shadow again, and so on.N3503601020Azimuth3403203301020Altitude30402903003102019304050605045607027028018181716708087668090June26025017161515141413 12 1113 12 1110109987120110100MarchSeptember240230220151413 12 11109140130210150December160200170190Figure 3.3 Sun-path diagram for latitude 50 northS*Petherbridge, P., Sunpath Diagrams and Overlays for Solar Heat Calculations. Research Paper No. 39,BRE, 1969.