Lexan PC automotive glazing has already established itself as a weight reducing technology that can result in lower fuel consumption and lower carbon dioxide emissions.
Now, advanced computer analyses of the thermal insulation benefits of Lexan PC automotive glazing have quantified the material’s potential to reduce the load on heating, ventilation and air conditioning (HVAC) systems based on the significantly lower thermal conductivity of PC vs. glass. The new findings underscore the value of using Lexan PC glazing to help drive improved efficiency for conventional, hybrid and electric vehicles. The findings come from the research and development team of Exatec, LLC, SABIC Innovative Plastics’ dedicated automotive glazing subsidiary.
“With this new research, we have given the industry a whole new way to think about the value of Lexan polycarbonate glazing, beyond the well-known benefits of weight reduction and styling freedom,” said Dominic McMahon, general manager of Automotive Product Marketing at SABIC Innovative Plastics and chief executive officer (CEO) of Exatec. “The significance of our findings is that automotive OEMs can get even more out of our portfolio of Lexan polycarbonate glazing solutions – benefits like extended range for electric vehicles and greater efficiency in air conditioning and heating systems. These findings also represent a natural complement to the solar energy absorbing capability of our infrared absorbing Lexan resins, which can be used to further reduce the heat load on a vehicle’s interior.”
The insulating properties of Lexan PC resin can reduce the demands on both heating and air conditioning systems. SABIC Innovative Plastics’ Exatec team used computational fluid dynamics (CFD) simulations of two car configurations, one with a PC backlite and rooflite, and the other with a glass backlite and rooflite. Simulations were performed for both hot and cold climates, considering stationary and moving vehicles.
The results showed that the lower inherent thermal conductivity of PC glazing relative to tempered glass can reduce steady-state total heat transfer between the inside and outside of the vehicle. This effect is expected to reduce emissions for conventional and hybrid power vehicles, and extend battery range for hybrid and electric power vehicles.
“This is a breakthrough in how to think about polycarbonate glazing,” said Stephen Shuler, Exatec’s chief technology officer. “Replacing glass with highly insulating Lexan polycarbonate glazing can help reduce demands on air conditioning and heating systems in hot and cold climates – and during both day and night driving. Our computer simulations show, for example, that these reduced demands can cut emissions by as much as three grams of carbon dioxide per kilometer, and extend electric vehicle battery range by two to three percent. This is in addition to the already recognized efficiencies provided by lighter weight polycarbonate glazing.”
Research and development by SABIC Innovative Plastics has resulted in a new family of new Lexan polycarbonate resin products with infrared (IR) energy absorbing capability. These commercially available products are formulated to reduce the amount of solar heat energy entering a vehicle’s interior. By absorbing solar energy, these Lexan products can further mitigate the load on air conditioning systems and help to improve fuel economy and lower emissions.