Key takeaways from this newsletter:

• The demand for coatings designed to reduce surface heat is growing.
• Cool coatings are designed to reflect solar radiation.
• Radiative cooling coatings reflect solar radiation and also cool by emitting infrared heat.
• As heat mitigation takes center stage, cool coating technologies are set to reshape how we design, construct, and safeguard surfaces—evolving from passive protectants into active agents of sustainable, climate-resilient infrastructure. 

There is a growing demand for advanced coatings engineered to minimize surface heat accumulation. Today, cool coating technologies are being deployed across a range of applications. In architecture, cool roof coatings reflect solar radiation to lower rooftop temperatures and reduce indoor cooling loads. In recreational settings, specialized pool deck coatings significantly reduce surface temperatures, enhancing comfort and safety for barefoot users. More recently, reflective coatings have begun to appear in transportation infrastructure, including railway systems, where excessive heat threatens operational reliability and material integrity.

A Brazilian railway company recently began applying white, water-based enamel paint to its train rails to combat rail buckling caused by extreme heat.(1) During hot weather, rail temperatures can soar to 70 °C (160 °F), leading to thermal expansion and separation at welded joints. The white coating has been shown to reduce rail temperatures by approximately 6 °C, helping to maintain structural integrity.

This approach is not unique to Brazil. Italy has employed white rail painting for years, and in April, Network Rail in London announced plans to use a white emulsion paint across its system. The London initiative is a response to frequent  rail buckling events resulting from excessive heating, which caused transit delays totaling 240 days last year. Network Rail estimates that painted rails can be 5 to 10 °C cooler than unpainted ones.

The effectiveness of white paint lies in its high solar reflectance. Unlike darker colors, which absorb sunlight and convert it into heat, white surfaces reflect more incident solar radiation, keeping them cooler. This principle underpins the widespread use of white coatings in cool roof technologies, which leverage reflective pigments to reduce building heat gain. In the U.S., the cool roof coatings market was valued at $4.5 billion in 2022 and is projected to reach $8 billion by 2028.(2)

A step above cool coatings  are radiative cooling coatings, which not only reflect solar radiation but also emit infrared heat in the 8–13 micron wavelength range—an atmospheric window that allows heat to escape into the heat sink of space. These advanced coatings can actually achieve surface temperatures below ambient air temperature and have been pioneered by institutions like Purdue University(3) and SRI International.(4) Though still in early development, radiative cooling technologies hold significant promise for future applications across the coatings industry.

As heat mitigation takes center stage, cool coating technologies are set to reshape how we design, construct, and safeguard surfaces—evolving from passive protectants into active agents of sustainable, climate-resilient infrastructure.

[1] Brazil Paints Train Rails White – Coatings World

[2]Can cool coatings combat climate change?

[3] This white paint could reduce the need for air conditioning by keeping surfaces cooler than surroundings - Purdue University News

[4] Self-Cooling Paint ™ – A Passive Radiative Cooling Solution - SRI

#innovation #coolcoatings #selfcoolingcoatings #radiativecoolingcoatings #purdue #SRI #coatings #chemicals #consulting

(photo credit: picture generated by Microsoft Copilot)