SunSmart® – PC Thermochromic Polycarbonate Sheets for Smart Roofing Applications

Heat management in buildings is a challenge that needs to be addressed to reduce the energy consumption and CO2 emission of buildings. Since Heating, Ventilation and Air-Conditioning (HVAC) systems are responsible for a large part of a buildings total energy consumption, it is important to regulate the heat flow through a buildings outer shell depending on seasonal needs. Windows and transparent façade or roof elements have been identified as the weakest thermal element in the building envelope. Especially regulating the solar heat flow through these transparent elements is of upmost importance for improved energy efficiency.

To address the seasonal changing requirements on solar heat gain, we are developing thermochromic materials that enable transparent elements to adapt their solar heat gain to a budlings seasonal needs. These so-called smart windows are ideal for intermediate climates with cold winters and hot summers, as they realize optimum usage of solar heat, reducing heating and air conditioning costs simultaneously and contributing to ‘net-zero’ construction.

One type of transparent building element are polycarbonate sheets, which are often used as roofing in e.g. conservatories. Polycarbonate sheets can be produced in multiwall and solid constructions, and the material itself is translucent, lightweight, and extremely durable. This makes polycarbonate sheets ideal for roofing applications.

By adding thermochromic functionality to polycarbonate (PC) sheets, a new type of transparent element with increased energy efficiency for the built environment can be established.

Within SunSmart PC we aim at developing thermochromic polycarbonate sheets for roofing applications via addition of TNO’s SunSmart® pigments into SABIC’s Lexan® polycarbonate.
These smart solar heat-regulating polycarbonate sheets will optimize the use of sunlight and solar heat in buildings. In addition, the SunSmart PC sheets will also contribute to reducing reliance on artificial heating and cooling systems.

By intelligently utilizing natural resources, such as solar heat, buildings can become more energy-efficient and reduce their ecological footprint.