Spectrally Engineered Cooling Covers for Sustainable Energy and Water Management in Greenhouses

Abstract

Researchers at the University of California, Davis have developed a multilayer coating designed to increase photosynthetically active radiation transmission while reflecting near-infrared light to reduce heat in controlled agricultural environments.

Full Description

This technology provides a greenhouse glazing structure with multiple alternating layers of zinc oxide, calcium fluoride, and silver, engineered to enhance the transmission of photosynthetically active radiation (PAR) beneficial for plant growth while reflecting near-infrared wavelengths (NIR) that generate excess heat. The multilayer coating reduces internal greenhouse temperature, minimizes cooling demands, and enhances water efficiency, particularly in arid climates. The coating is fabricated using scalable, low-cost thin-film deposition methods, optimized layer thicknesses, and optional adhesion and wetting layers to maintain durability and optical performance under humid agricultural conditions.

Applications

• Greenhouse glazing panels for sustainable controlled-environment agriculture. 
• Protective coatings for glass or polymer substrates in agricultural buildings. 
• Agricultural produce facilities aiming to increase crop yield and reduce resource consumption. 
• Commercial greenhouse operations in hot or arid climates with high cooling loads. 
• Energy and water-efficient horticulture installations worldwide.

Features/Benefits

• Maximizes crop growth efficiency by transmitting high levels of photosynthetically active radiation (PAR). 
• Reflects substantial near-infrared radiation (NIR) to reduce unwanted greenhouse heat accumulation. 
• Lowers energy and water consumption by minimizing cooling requirements. 
• Maintains durability and humidity resistance in agricultural environments. 
• Enables cost-effective, large-scale thin-film fabrication. 
• Allows precise optical tuning through layer thickness adjustments without complex inverse design. 
• Improves film clarity and conductivity using specialized wetting, adhesion, and annealing layers. 
• Prevents excessive heat build-up in greenhouses from near-infrared solar radiation. 
• Reduces high energy and operational costs for greenhouse cooling. 
• Reduces excessive water consumption in controlled agriculture due to evaporative cooling. 
• Protects crops from yield loss caused by temperature stress and thermal damage. 
• Prevents coating degradation from humidity and environmental exposure. 
• Addresses complexity and cost barriers in manufacturing scalable, effective spectrally selective coatings.

Patent Status

Patent Pending