The building glazing heat challenge
Commercial and residential buildings lose thermal efficiency through their windows. In warm climates and during summer months, solar heat gain through glazing drives cooling energy demand — the single largest energy cost in many commercial buildings. The challenge is to block the near-infrared (NIR) component of solar radiation (the heat) while maintaining visible light transmission (daylight and views).
Conventional solutions include tinted glass, low-e coatings, and reflective films. Each has limitations: tinted glass reduces daylight, low-e coatings require vacuum deposition, and metallic reflective films attenuate radio frequencies and create aesthetic issues. ATO nanoparticle coatings offer a different approach — selective NIR absorption without visible light reduction, applied via wet-coat processing.
ATO for architectural glazing
Kriya's bottom-up synthesised ATO nanoparticles — proven in automotive glazing — translate directly to architectural applications. The key performance characteristics:
- Selective NIR absorption — blocks solar heat while transmitting daylight
- Tuneable solar heat gain coefficient (SHGC): 0.2 to 0.7, adjustable by ATO loading
- Haze below 0.3% — invisible to occupants, no visual distortion
- 100% RF transparent — no interference with 5G, Wi-Fi, or building communication systems
- No colour shift — neutral appearance unlike some tinted or reflective alternatives
Building-integrated PV glazing
Building-integrated photovoltaics (BIPV) combine energy generation with building envelope function. BIPV glazing — windows that generate electricity — faces a unique challenge: the PV cells absorb solar energy for electricity, but the non-cell areas still transmit unwanted heat. ATO coatings on the non-cell areas or on the glass substrate can:
- Reduce heat gain through the transparent portions of BIPV glazing
- Improve occupant comfort without reducing PV output
- Lower cooling energy demand, improving the net energy balance of the BIPV installation
Delivery formats for architectural glazing
Kriya delivers ATO for architectural applications in multiple formats:
- PVB masterbatch — for integration into laminated safety glass during manufacturing. The same format used in automotive, adapted for architectural glass dimensions and PVB thickness.
- Window film — for retrofit application to existing building glazing. Applied to interior surfaces of existing windows without glass replacement.
- Sol-gel coating — applied directly to glass surfaces. Thermally cured to produce a durable oxide film with excellent weathering resistance.
Energy savings and sustainability
The energy impact of solar heat control glazing depends on climate zone, building orientation, and glazing fraction. Under reference conditions (similar to the automotive validation using Calculation Model 887):
- Interior temperature reduction: up to 9 degrees Celsius compared to uncoated glazing
- Cooling energy reduction: up to 35%
- Visible light transmission maintained: above 60%
For green building certifications (LEED, BREEAM, WELL), solar heat control glazing contributes to energy performance credits and occupant comfort metrics.
RF transparency advantage
Modern buildings depend on wireless connectivity — 5G, Wi-Fi 6E, IoT sensors, and building management systems. Metallic low-e coatings and ITO-based solar control films attenuate RF signals, creating dead zones inside buildings and requiring expensive signal boosters. Kriya's ATO is 100% RF transparent — confirmed across 5G frequency bands — meaning solar heat control does not compromise building connectivity.
Durability and weathering
Architectural glazing must perform for decades. Kriya's sol-gel ATO coatings produce dense oxide films with demonstrated resistance to:
- UV exposure — no degradation under accelerated weathering
- Humidity and moisture cycling
- Cleaning chemicals used in building maintenance
- Temperature cycling from seasonal and diurnal variation