The effect of reflective coatings on building surface temperatures, indoor environment and energy consumption—An experimental study

This paper presents an experimental study on the impact of reflective coatings on indoor environment and building energy consumption. Three types of coatings were applied on identical buildings and their performance was compared with three sets of experiments in both summer and winter. The first experiment considers the impact of coatings on exterior and interior surface temperatures, indoor air temperatures, globe temperature, thermal stratification and mean radiant temperatures for non-conditioned buildings (free-floating case); the second one focused on the impact of coatings on reduction of electricity consumption in conditioned spaces; in the third experiment, the impact of different envelope material properties equipped with different coatings was investigated. The results showed that, depending on location, season and orientation, exterior and interior surface temperatures can be reduced by up to 20 °C and 4.7 °C respectively using different coatings. The maximum reduction in globe temperature and mean radiant temperature was 2.3 °C and 3.7 °C in that order. For the conditioned case, the annual reduction in electricity consumption for electricity reached 116 kWh. Nevertheless, the penalty in increased heating demand can result in a negative all-year effect in Shanghai, which is characterized by hot summers and cold winters.