Analysis of temperature trends for the last 100 years in several large U. S. cities has indicated that since -1940 there has been a steady increase in downtown temperatures of O. l-0.5°C per decade (-0.5°C for larger cities like Los Angeles and 0.1°C for smaller cities). Typically, electricity demand in cities increases by 2-4%/°C, hence, about 5-10% of the current urban electricity demand is spent to cool buildings just to compensate for the urban heat island effect. Downtown Los Angeles, for example, is now 3°C warmer than in 1940 leading to an increase in electricity demand of 1500 MW.
Solar control devices placed in front of large building openings disturb air flow and theradiation transfer. Although solar radiation transfer through obstructed openings is arelatively well researched area, very little information is available regarding the air flowperturbations and daylighting alterations created by external solar control devices. Thepresent paper reports a series of experiments aiming at investigating natural ventilationand daylight phenomena associated with the use of specific shading devices.
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