Impact of a cool roof application on the energy and comfort performance in an existing non-residential building. A Sicilian case study

Abstract

The vernacular Mediterranean architecture was characterised by passive solutions able to ensure thermal comfort conditions in the built environment during the hot season. The use of light colours to redirect most of the incident solar radiation was based on these traditional solutions. Cool roofs are a mix of ancient concepts and modern technologies; their application in new and existing buildings can significantly improve the energy efficiency during the cooling season and throughout the year. The paper reports the results of a large application in an office/laboratory building belonging to a school campus in Trapani, on the west coast of Sicily. The experiment was carried out in two phases. The building was continuously monitored during the first phase from late April to late September 2009: indoor and outdoor air temperatures, relative humidity and solar radiation were acquired. The monitoring was carried out before and after the cool eco-friendly white paint application, characterised by high solar reflectance and thermal emittance. The monitored data were used to calibrate the building model input into a dynamic simulation tool, used to evaluate the building performance with a number of variants. The analysis gave interesting results on the potential of this technique for the southern European climatic conditions.