ENERGY EFFICIENCY MEASURES UNCOUPLED FROM HUMAN PERCEPTION: THE CONTROL OF SOLAR SHADING SYSTEMS IN RESIDENTIAL BUILDINGS

Glazing surfaces strongly affect the building energy balance considering heat losses, solar gains and daylighting. Appropriate management of screens is required to control the incoming solar radiation, preventing internal overheating but assuring visual comfort. Consequently, in the building design phase solar control systems have become crucial devices to achieve high energy standards, to be exploited also in the refurbishment of existing buildings, especially in warm climates. Automated systems guarantee additional energy efficiency because of a model of use and operation of the shielding independent of the personal choices of the users. Usually, these choices are guided by personal perception and beliefs, often conflicting with common sense, and not by the search and optimization of environmental comfort. Instead, management based on well-defined control strategies can help reduce cooling consumption and ensure natural lighting. Among the control parameters to be monitored, there may be the intensity of solar radiation, the external and internal air temperature, the level of internal natural light and the occupancy. The greater the degree of automation and control of the sunscreen, the greater becomes its effectiveness in ensuring the level of expected solar and light control. The present study aims at investigating the effect of different screening strategies on the energy consumption of a high-performance building designed in the Mediterranean climate. The screen type consisting of blinds with horizontal slats is examined at the variation of its position with respect to the glazed surface and according to different control parameters.