# Performance of Solar Control Films on Building Glazing: A Literature Review
###### Abstract  
Buildings with a high window-to-wall ratio tend to suffer from excessive solar gains/losses that usually result in high energy demand and discomfort for occupants. Solar control films (SCFs) are a passive solution with the potential to increase the performance of new or refurbished glazing they are applied to. This paper presents a comprehensive literature review of the performance of SCFs applied to glazing systems of buildings. Research studies with experimental, analytical and computer simulation approaches were gathered and analyzed, identifying glass and film systems, climatic conditions, energy savings and comfort performance. The research approaches and main findings of existing research studies were compared and discussed. The presence of SCFs significantly reduced indoor solar radiation and illuminance levels, particularly with reflective films applied to south-oriented glazing (northern hemisphere). Glazing systems with SCFs were reported to promote cooling energy savings compared with clear glazing in hot climates. Few studies have explored the visual and thermal comfort performance of SCFs, concluding that these films promote thermal comfort, and reduce excessive illuminance and potential glare. Furthermore, this paper helps to highlight areas of guidance for future studies on the topic. solar control film; thermal performance; luminous performance; energy performance; indoor comfort +
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and for high indoor illuminance levels that can lead to discomfort glare, it is important to promote solar control solutions that can enhance the performance of windows. Some of these more conventional solutions, such as overhangs, blinds and louvers, have, as drawbacks, the requirement of altering the type or structure of the existing glazing/fenestration and the possible blocking of the outdoor view. Research and development in the field of glazing systems have experienced a rapid evolution with several innovative breakthroughs, such as laminated glass panes in the 1920s and coated products in the 1970s. Since then, the traditional clear single-glass window, which has a poor performance, has evolved to produce more efficient solutions such as double or triple glazing, low-emittance windows with low thermal transmittance, vacuum glazing, electrochromic windows [8; 9], thermotropic materials [10; 11], silica aerogels [12] and transparent insulation materials. More recently, the development of transparent selective coatings and films [13; 14; 15] provides a wide range of solar optical properties for glazing surfaces, admitting high daylight levels while preventing excessive heat gains through the glazing. Some of these innovative and modern window technologies [8; 10; 11] can dynamically alter their properties to control the amount of incoming light and heat by responding to environmental stimuli or user requirements. As a result, these smart window technologies can improve the building's global performance by optimizing energy use, peak demand and indoor comfort in real time. Smart window technologies have undergone rapid development in the last years, particularly in windows that respond to electro-, thermos-, mechano- and photo- stimuli [4]. Electrochromic windows are a promising and attractive window technology from research, design and user perspectives, with several products currently available on the market. This type of smart window has a better performance in climates with different needs for winter and summer seasons and different facade orientations [9; 16]. Photochromic and thermotropic passive smart windows that react to light and heat stimuli, respectively, are also attractive solutions with a lower economic cost than active windows [10; 11; 17]. Nevertheless, these passive smart windows have the absence of control by the user as a disadvantage.