Heat-Reflective Car Paints

A significant part of the efforts to reduce emissions from cars have focused on improving the fuel efficiency, using alternative fuels and installing hybrid engines. These efforts are indeed critical for reducing greenhouse gas emissions. Taking the initiative further, efforts are on to produce car paints that can reflect heat and reduce the dependence on air-conditioning systems in vehicles. Air-conditioners are known emit CFCs into the atmosphere which damage the ozone layer and add to global warming.

These “cool paints” are currently being used in the construction industry for building houses that can reflect the heat and thus reduce consumption of electricity that is normally required by cooling systems.

High interior temperature within a parked car is the reason why air-conditioning systems are frequently used. The problem of high interior temperature is caused by the presence of a pigment “carbon black” in automotive paint. Carbon black is needed for darkening the colors. Carbon black absorbs a lot of sunlight. The air-conditioning system draws some of the horsepower from the engine using certain belt-driven compressors thus leading to higher consumption of fuel by the car.

The use of lighter shades is an obvious answer to the problem but most car owners prefer either black or other darker shades for their cars. Hence research is on to find ways to reduce vehicular emissions by reflecting the heat through improved paints (all shades and not specifically darker ones) that contain coatings or pigments that can achieve optimal reflection of heat.

The two options for paints suggested are the use of Infrared (IR)-transmissive paints and IR-reflective paints. IR-transmissive paints use a transparent pigment that allows passage of infrared light through to a primer layer that will reflect the light away from the car. IR-reflective paints use a reflective pigment as a mixture along with the base coat.

Besides this, there is an effort to design a better glass for the windshields, rear and side windows of a car. The new glazed glass can reflect sunrays away from the car without inconveniencing other drivers on the road by causing glare.

These techniques will help in reducing the heating up of the interiors of a car. The savings achieved through the use of these techniques are very significant. The efficiency of cars running with the air-conditioning turned off is around 20% more than those in which the air-conditioning remains on.