Translucent component to provide thermal energy saving in buildings

Abstract

The paper presents a study based on the perceived need to increase the building performance and quality of indoor comfort conditions, reduction of the unnecessary CO2 emissions and superfluous costs. In Europe, on average the consumption of energy in buildings constitutes 40 % of the total consumption of energy. Approximately 70 % of the consumed energy is used for heating and cooling houses. The physical characteristic transparent or translucent building components like windows are the weakest elements of the building envelope. Their U value is usually 4 times higher than for opaque ones causing a considerable increase of heat loss during winter. In summer relatively high solar transmittance is a source of undesirable heat gains which result in overheating. The main reason for investigation of transparent building components is the very low heat saving capacity of such building components. During the whole year the radiant asymmetry close to the window surface influences thermal comfort. On the other hand, glazing elements are necessary in buildings to provide the required amount of daylight, preferably in a diffuse form. The specific challenge of the paper is development of new phase change material (PCM) glazing components for better building energy performance. The goal could be achieved by improving the heat capacity and heat transfer coefficient of transparent components by phase change materials application. The effect of latent heat storage of solar energy will result in an effective heat transfer coefficient and in this way PCM use helps ensure the level of comfort indoors. The novelty in investigation of the PCM glazing components will be introduced by taking into account as the main the following aspects – investigation of heat exchange processes in the PCM layer during energy storage and heat exchange by convection and radiation as well as determination of real performance of PCM glazing components under different weather conditions and, of course, practical construction solution of components including their movability.