Seite - 96 - in Intelligent Environments 2019 - Workshop Proceedings of the 15th International Conference on Intelligent Environments

Fig. 5. Thermal conductivity dependence with iron (III) oxide content of the lime mortar. 4. Conclusions Two methodologies of improving energy savings have been analysed using different techniques. On one hand, the cold painting is analysed using a wood made room and performing measurements in a real environment outside the laboratory. In the other hand, the addition of iron(III) oxide to lime mortar is analysed in the laboratory observing several physical features. Results of wood made panels shown a significant energy saving of up to 70% on floor beams and 30% on floor planks, compared to a concrete/steel construction methodology. At the same time, the use of cold paints reduces up to a 15% of surface temperatures, compared to a referenced building. This reduction promotes air conditioning energy savings of up to 344.2 kWh/m2 and 45.6% less power consumption. Results of additions of iron (III) oxide appear to be an efficient and promising way to enhance the thermal insulating capacity of a lime mortar. The addition of 20% of Fe2O3 decreases the thermal conductivity from 0.67 W/m·K to 0.40 W/m·K, which means a 40% of energy saving. Thermal conductivity, λ, shows a strong dependence on iron (III) oxide content. The factors affecting the thermal behaviour can be summarized as follows: 1. Thermal conductivity of the used additive, iron (III) oxide, is lower than that of the lime (mortar base material). 2. Bulk density is reduced by the iron (III) oxide addition for two reasons. Firstly, the larger quantity of water added to the mixture of dry powders increases the porosity generated during curing process. Secondly, submicron Fe2O3 particles surrounding lime particles cause a separation of lime particles. A decrease of bulk density involves a higher porosity, passing from 42% in M-0 to 49% in M- 20. Since the air contained in pores has a thermal conductivity at least 20 times lower than iron (III) oxide or lime mortar, the resulting λ, following the rule of mixture, becomes much lower. B.Alordaetal. /OverheatingMitigationStrategiesAnalysis: AMediterraneanCaseStudy96