To face the increasingly urgent need to reduce the energy demand in buildings, the Eensulate Project proposes a glazed façade system based on VIG technology coupled with a thermochromic coated glass, the EENSULATE curtain wall module.
Thermochromic thin film has become a recognized potential solution for the reduction of the solar radiation entering into a glazed system due to its intrinsic ability to modulate the solar heat gain of the glass as a function of its temperature. This “intelligent” property of the thermochromic film distinguishes the insulation nature of the window from any other passive solution, like VIGs that have the same degree of insulation whatever the ambient temperature. On the contrary, the thermochromic window has a dynamic behavior as it allows or not the solar radiation entering through the glazed facade depending on the temperature reached by the thermochromic coating. In fact, below a certain temperature, called switching temperature, the coating allows solar radiation entering the building while above this temperature the solar radiation is reflected outside preventing indoor overheating.
From previous investigations, it is known that thermochromic material properties (switching temperature, hysteresis gradient and width) can be altered through variation of synthetic route, mainly by acting on the material doping. However, no attention has been paid to how such alterations affect the overall building energy performance and the consequent savings attributed to the materials.