Roofs spend the day soaking up sunshine, and air conditioners spend the afternoon fighting the result. A white paint from the University of South Florida (USF) takes a different approach: instead of merely absorbing less heat, it sends heat away, and it has now been shown to cool a surface below the air around it in a month of real outdoor testing in Tampa.
According to USF’s announcement on November 5, 2026, the self-cooling coating was created in the lab of Distinguished University Professor Yogi Goswami. It reflects up to 98% of sunlight and cooled test surfaces by as much as 13.5 degrees Fahrenheit below ambient air temperature.
n toWhy cooling is such a big energy problem
Goswami points out that about 25% of all energy used in the United States goes toward cooling buildings. He also notes that air conditioning is spreading in places where it was once uncommon, such as Europe, while populous countries like India and China are gaining wider access to cooling. Climbing global temperatures add to the pressure. That combination is what pushed him to look for a passive option that needs no electricity to run.
How the paint uses the sky as a heat sink
The key idea is radiative cooling. USF explains that the paint uses the extremely cold temperature of outer space as a heat sink. Earth’s atmosphere has a natural window that lets certain wavelengths of heat pass through rather than being trapped near the ground. Goswami’s team engineered the paint to emit heat in exactly those wavelengths, so thermal energy escapes toward space and the painted surface stays cooler.
That is different from a conventional cool-roof paint. As USF describes it, standard cool-roof coatings mainly reduce how much heat a roof absorbs. This coating goes further and can drop a surface below the temperature of the surrounding air. The university adds that the paint is made from natural materials designed to reflect sunlight, and it was developed at the USF TECO Clean Energy Research Center.
What the outdoor test showed
Many earlier studies of radiative cooling paints were run indoors under controlled conditions. Goswami argues that is not where cooling is needed, so his team moved the experiment outside. They built three test samples, each with thermal insulation at the base and aluminum foil on top. One sample was coated with the new paint, one with a commercial cool-roof paint, and one was left as bare foil.
- Thermometers on each sample logged temperatures from 10 a.m. to 5 p.m.
- The test ran for 28 days in Tampa, Florida.
- The new paint recorded the lowest temperatures of the three samples.
- It stayed consistently below ambient air temperature, with a peak reduction of 13.5 degrees Fahrenheit.
It is worth keeping the scope in mind: these are measurements on small insulated test blocks, not on whole buildings, and USF has not published building-level energy savings. Goswami has said he expects the paint could cut energy bills by 50%, a projection from the researcher rather than a measured result.
From lab sample to something you can buy
The technology is covered by a provisional patent application. The next engineering hurdle is durability: the lab is developing a transparent protective coating to go over the paint so it can withstand wind and rain while keeping its cooling performance. Goswami says the team is working to make the product commercially available, and expects commercial buildings to adopt it first, followed by homes.
What it means
If the protective layer works as hoped, this kind of coating could become a low-cost retrofit for flat roofs and warehouses, the buildings where cooling loads are largest. Because it is passive, it keeps working during peak afternoon demand without drawing power, which is when grids are most stressed. The open questions are practical ones: how long the coating lasts outdoors, how dirt and weather affect its reflectivity, how it performs in humid climates beyond the Tampa test, and what it will cost compared with ordinary roof paint.
Bottom line
USF’s self-cooling paint is an early but encouraging example of cooling by design rather than by electricity. A 28-day field test in Florida is a meaningful step beyond indoor demonstrations, and the next milestone, a durable protective coating, will decide whether it reaches roofs at scale.