Effects of the Solar Reduction Glass on the Car Occupant's Thermal Comfort by a Numerical Simulation

Thermal comfort for car occupants is important factor for automotive design. We have been developing efficient solar reduction glass for vehicles. We also developed a numerical simulator to predict and evaluate the thermal environment and thermal comfort in vehicles. In this simulation, firstly distribution of solar radiation energy through the glass can be calculated actually, and then temperature and air flow distribution, and human comfort can be computed by a combined analysis of CFD (computational fluid dynamics), thermal radiation and body temperature control model which corresponds to shapes of a vehicle and human body. The thermal environment differences between solar reduction glass and normal glass should be clear, which makes the effects of functional glass clear from the view point of human comfort.

We can calculate comprehensive situations and indices of thermal comfort evaluation. Using this simulator, it was confirmed quantitatively that Asahi Glass's solar reduction glass could reduce the air-conditioning power than normal glass in summer condition. Further more, it was confirmed quantitatively that our functional glass could supply more comfortable environment for passengers inside car occupants. This result shows the latest value of automotive glass depending on human feelings.