ATO Nanoparticle Solar Heat Control for Automotive

The cabin heat problem in modern vehicles

Modern vehicle design trends — panoramic roofs, larger windshields, minimised A-pillars — increase the glazed area exposed to solar radiation. The result is higher cabin temperatures, greater air conditioning demand, and for electric vehicles, a direct reduction in driving range. In a parked vehicle on a sunny day, interior temperatures can exceed 58 degrees Celsius.

For EVs, this is not merely a comfort issue. The AC compressor is the single largest parasitic electrical load after the drivetrain. Every watt spent on cooling is a watt not available for propulsion. Solar heat control at the glazing level — blocking near-infrared radiation before it enters the cabin — is the most effective intervention point.

ATO vs ITO vs competing solutions

Several materials compete for the automotive solar heat control market. Antimony tin oxide (ATO) offers a distinct combination of advantages:

ITO offers good optical quality but attenuates RF signals — a growing problem as vehicles integrate 5G connectivity, V2X communication, and ADAS radar. Milled ATO is cheap but optically unacceptable for automotive glazing. Kriya's bottom-up ATO uniquely combines optical clarity, RF transparency, and cost efficiency.

Bottom-up synthesis advantage

Kriya synthesises ATO nanoparticles from atoms up via proprietary chemistry, producing particles with controlled size distribution and morphology. Competitor products — including the industry standard from a major Japanese mining company — use ball-milling (top-down) to grind bulk ATO into nano-sized particles. The grinding process produces irregular, broadly distributed particles that scatter visible light.

The result is measurable: Kriya ATO achieves haze below 0.3% after lamination (automotive grade), while milled competitor ATO produces haze above 1.7% — far beyond the threshold for automotive glazing qualification. At equal solar heat gain coefficient (SHGC), Kriya's ATO is 5 times more effective at blocking near-infrared radiation while maintaining visible light transmission.

Three delivery formats

Kriya delivers ATO in three formats to match different integration pathways:

• PVB masterbatch — pre-dispersed ATO in polyvinyl butyral interlayer resin. The automotive mass-market format. A leading Tier-1 PVB interlayer partner has validated this format for laminated windshield and side glass production. A 1,000,000 kg annual capacity plant is fully engineered, with a location option adjacent to the partner's factory at Chemelot Industrial Park, Netherlands.
• Window film — ATO-loaded polymer film for aftermarket and retrofit applications. Applied to existing vehicle glazing without glass replacement.
• Sol-gel direct coating — applied directly to glass surfaces for lightweight, ultra-thin solar heat control. Suitable for specialty and low-volume applications.

Measured performance

Under reference conditions (ambient 28 degrees Celsius, solar radiation 600 W per square metre), Kriya ATO solar heat control delivers:

• NIR blocked: 250 W per square metre
• Interior temperature reduction: 9 degrees Celsius
• AC power reduction: 35% (from 1.44 kW to 0.93 kW)
• Total solar transmittance: 41%
• VLT at 515 nm: 64.4%
• NIR transmission at 1400 nm: 1.8%

These values are calculated using Calculation Model 887, validated at r-squared = 0.999 against field measurements.

EV range extension: 7 to 16 km

The AC power reduction from solar heat control translates directly to EV range extension. Using validated calculations across EV segments:

• Premium EV (average 85.6 kWh battery, 442 km WLTP range): up to 16 km extension, with 8.5 kg battery weight saving worth approximately 325 euros
• Compact EV (average 39.3 kWh, 227 km WLTP): up to 7 km extension, with 4.6 kg battery weight saving worth approximately 159 euros

For more on the range extension case, see the dedicated EV range extension page.