Luxury car companies keep it cool inside with advanced glass coatings

Automakers are using advanced glass coatings to keep vehicle cabins cool, alleviating the air-conditioning load as summer sweeps India, sending temperatures past 45°C in some cities. The push comes as vehicle sizes, glass surface areas and thermal loads grow with the shift toward larger vehicles such as SUVs and electric models requiring increased battery pack space. With glass typically comprising 25-30% of a vehicle’s surface area, and that percentage rising consistently with increased sunroof adoption, moderating the sun’s fierce heat with glazing is becoming critical, car makers said.

Over the past few years, average windshield area has increased 8% and total glass surface is up 12% as cars have become bigger, according to Jato Dynamics estimates. Automotive glass suppliers have developed specialised solar-reflective coatings incorporating ultra-thin layers of metal oxides such as silver, zinc and tin. These transparent metallised coatings absorb solar infrared radiation to reduce interior temperatures. Amid rising global temperatures, the role of advanced glass coatings is a must-have solution to beat the searing summer heat. Their widespread adoption aligns with vehicle electrification and enhanced safety features, said experts.

Luxury car makers such as Mercedes, Audi, Volvo, BMW have been prioritising these thermally insulated glass technologies. Leading suppliers like Asahi, Saint-Gobain and Webasto offer specialised automotive glazing products.

Mercedes equips select top-end models such as the EQS 580 sedan, GLS SUV, Maybach GLS 600, Maybach S680 and Maybach S580 with “acoustic comfort packages” fitted with infrared-absorbing laminated glass. “Not only does this special glazing block harmful UV rays, it reduces exterior noise penetration and prevents excessive heat build-up in the cabin, even during India’s harshest summers,” said Santosh Iyer, MD, Mercedes-Benz India.

Heat-reflecting Windshields Deployed

At Volvo Car India, “we prioritise comfort and safety through cutting-edge heat and UV protection technologies like infrared-reflecting coatings on our sunroofs,” said MD Jyoti Malhotra. “This blocks about 80% of solar heat gain to ensure optimal cabin temperatures.” Audi India said heat-reflecting windshields and side glass are deployed in several models such as the A8, Q8, RS5 and the e-tron EV, though not silver-based coatings specifically. The increased thermal load from larger EV battery packs makes effective cabin cooling solutions even more essential. “For extreme conditions like the current heat wave, windshields and sunroofs with silver-based coatings can decrease cabin air temperatures compared to conventional glazing and customers are now demanding comfortable cabin environments,” said a senior executive at a glass and window solutions company. Metallised coatings are just the beginning when it comes to hightech automotive glazing solutions for extreme weather, said Ravi Bhatia, regional director of Jato Dynamics.“Increasing use of head-up displays, 5G connectivity and even integrated antennas will necessitate coatings to control solar heat,” he said. Managing heat will become paramount for glass suppliers and they’ll be pushed to create more sophisticated coatings combining solar control and electromagnetic properties, Bhatia said.