Comparison of the thermal behavior of constructive materials and phase change materials for their use as thermal mass in a roof for Santiago de Querétaro climate

Abstract

There are several constructive techniques such as green roofs, active green roofs (Roche, 2013) or roofs with water tank (USC, 2016), which benefit from the solar energy to climatize interiors. These and other types of thermal mass own certain properties that facilitate the storage of heat inside of their masses. Precisely in Santiago de Querétaro is where the thermal mass can soften the hits of the heat caused by its great thermal difference between the day and the night and by high level of solar radiation in the zone. This article contains the comparison of possible materials to accumulate the heat as a part of a roof’s system. There is a great variety of constructive materials that are able to perform the function of a thermal mass. Besides, there are some materials that do not have much mass but still can store large quantities of heat inside its masses because of the latent heat during the processes of their fusion. Some constructive materials are chosen because of their properties to store the heat and some calculations are made to define their thickness based on the necessity to offset the thermal heat wave for 12 hours. As well, some phase change materials are chosen and some calculations are made to define their thickness according to the climate’s conditions of the zone. In the end, the comparison of the selected materials is made according to their possibilities to maintain their temperature close but above 27°C.