Evaluation of latent heat storage in mortars containing microencapsulated paraffin waxes – a selection of optimal composition and binders

The application of phase change materials (PCMs) in mortars have been extensively researched, however, most studies are focused in one single binder. Conducting comparative assessments using different binders can facilitate the development of compositions with adequate heat storage and suitable mechanical properties. In this work, several PCM-mortars using cement, lime and gypsum as binders, have been studied using a laboratory simulation that mimicked the day/night temperature changes that the material will be subject during service applications. It has been demonstrated that the addition of PCMs in mortars allows the material to retain heat, indicating that these mortars can have a positive impact on the overall energy demand of buildings. There is a combined effect of delay and lowering of temperature peaks, triggered by the heat released from the capsules. The cells with PCMs showed not only a smaller temperature gradient between night and day, but it also exhibited lower peaks. The tests conducted with this laboratory setup prove that PCMs can be successfully mixed into mortars without compromising its durability, hence their applicability as wall renderings.