Scientists at Purdue have created a white paint that can cool a building

Yes, that's correct! Scientists at Purdue University have indeed developed a special white paint that has the ability to cool buildings. The paint is designed to reflect nearly all the sunlight that hits its surface, preventing the building from absorbing the sun's heat and keeping it cooler.

This innovative paint is known as "ultra-white" paint. Its unique formulation consists of a high concentration of barium sulfate, which gives it its exceptional reflective properties. Barium sulfate is a common compound used in various applications due to its ability to scatter light effectively.

By applying this white paint to the exterior of buildings, it can significantly reduce the need for air conditioning and help lower energy consumption, especially in hot climates. This could potentially have a positive impact on both energy efficiency and the environment.

Researchers are continuously exploring new ways to develop energy-efficient technologies, and this ultra-white paint is a promising development in the field of sustainable building materials.

Even before the advent of modern sciences, people in tropical and sub-tropical areas have used limestone powder to pain their homes just two months before the start of summers. People used to excavate limestones, then put them through kiln to produce quicklime. These methods have been known for ages in such areas, even before modern Chemistry.

It is time to study how people survived in tropical areas, what kind of houses they built, how they cooled their homes, what kind of trees they used for shading, etc. And use modern science to better understand the traditional methods, then refine and/or find better alternatives. Instead of this, the governments, the research institutes, and the builders in the tropical areas, just build concrete jungles, thereby making homes as heat domes.

Here is a frankly incredible video of how you could make such a paint if you were so inclined. I don't think it's very practical, but the video is very interesting anyways

https://youtu.be/KDRnEm-B3AI

White paint is good. Special maybe-toxic (mentioned in the article) white paint to reflect 98% instead of 85% is not necessarily a great idea, though. If it's substantially more expensive, and it surely will be, you could do more good with your money by simply using more normal white paint.

From the article: "... work is underway to increase its durability and dirt resistance."

It really doesn't matter how well it works on day one. What matters is how well it works on an annual basis or over the lifetime of the applied coat of paint. Obviously they're not there yet or it'd be on the market. They've been working on this since at lease 2020. I hope they're able to come to market soon.

I wonder if this paint, or rather type of paint - radiative cooling paint, only works for roofs and other sky-pointed surfaces.

Related:

https://news.ycombinator.com/item?id=28573311

https://news.ycombinator.com/item?id=26832589