Effect of horizontal overhangs and glazing with spectral radiative properties on annual thermal balance of the building and thermal comfort

The annual solar gains in public buildings with large percentage of glazing can be shaped by different kind of shading constructions and glazing with proper spectral radiative properties. These properties can be obtained by covering panes with special spectral selective covers or by colouring panes in mass. Spectral selective panes enable control of solar gains in summer, reduce heat loss in winter and reduce electric energy for cooling. These elements, except obvious influence on the annual heat balance of the building, have an impact on parameters of thermal and visual comfort. The paper presents selected results of the influence of horizontal overhangs and glazing with special spectral radiative properties on the annual thermal balance of analysed buildings (computer analysis) and on thermal comfort of users (measurements). Microclimate measurements show that it's impossible to maintain thermal comfort conditions during hot summer in natural ventilated buildings with high percentage of glazing without any additional appliances.