ZEMCH 2015 - International Conference Proceedings | Page 581

During the summer period and the hottest hours the thermochromic coatings could exhibit a
lighter colour and therefore reflect the most of the solar radiation, in order to contribute to the
role of the thermal insulation and heating protection. During the winter season and the coldest
hours, the same coatings could change in a darker colour and then contribute to the absorption
of the radiation and the increasing of the solar gains to be transferred to the existing wall, which
could work as thermal accumulator. Ultimately, the research project proposes an architectural
system inspired by the biological behaviour of the animals that, like the side-blotched lizard, is
able to thermoregulate the internal comfort depending on the external environment.

Figure 4: Scheme explaining the dynamic optical properties of the thermochromic coating, depending on the variability of solar radiation and temperature, during the cycle day/night and summer/
winter (image by Cecilia Mazzoli)
The researches thus far conducted by the Universities and the Research Institutes and their comparative results demonstrate that “the use of thermochromic coatings can contribute to energy
savings in buildings, providing a thermally comfortable indoor environment” (Karlessi et al. 2009).
Actually the thermochromic paints experimented for the application to the existing façade specifically provide the control of the absorption or reflection of the solar radiation and can contribute to improve the thermal performances of the façade. The technology advancements let
perceive a real potential in the use of thermochromic paints and coatings, in order to create an
innovative product, responsive and adaptive, to be used for controlling the thermal behaviour of
the building façade.
The next stages of the research will include the realization of further prototypes and measurement tests on this new industrial product, which are essential in order to validate the new bio-mimetic façade system aimed to optimize energy efficiency through the use of innovative materials
in the creative building industry sector.

5. Conclusions
It is nowadays necessary to stimulate the excellence in energy performance up to the ambitious
nZEBs targets, technically achievable in the most inefficient buildings of the modernity, which represent the majority in EU. A new culture of sustainability in the construction sector must involve
the use of environmentally friendly materials for thermal insulation systems, the minimization of
the consumption of embodied energy and the flexibility according to the consumers’ needs. In
this framework, the progresses made through the interventions inspired by sustainability principles are easily recognizable in the field of energy efficiency and materials technology, in terms of

Towards nZEBs: innovative materials and technologies for new sustainable envelope

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