Energy saving in glazed surfaces by using solar and thermal control films

Abstract

 Energy balance numerical results corresponding to a building located in a Temperate Cold bioclimatic zone are presented. Our purpose is to analyse the performance of thermal control films applied onto glazed surfaces. Low emissivity films are placed on the internal glazed faces and high reflectivity films are placed on the external ones. One scenario in which the internal temperature remains constant and another in which the value of this temperature is not restricted are considered. According to the floor and facades orientation, the entering direct solar radiation, the diffuse radiation per surface unit, and the heat flux through the glazing are calculated. We found that the low emis­sivity films produce a reduction in the energy required to provide optimal habitability conditions throughout the year when they are installed on simple and double glazed windows, reducing the solar radiation to a third in summer. The total energy savings by using the external films is 85% less than that produced by using transparent windows or just low emissivity films, generating the maximum saving in summer and the need for more heating in winter.