Technology keeps marching forward, even for more mundane items such as paint. But what if advanced cooling paint technology meant you no longer needed air-conditioning in your RV? Getting by comfortably with just a trusted Sirocco fan would certainly make staying off-grid longer easier!
Stanford University Scientists have invented a new kind of paint that could potentially allow you to paint your RV almost any colour you please. According to a study published in the Proceedings of the National Academy of Sciences, the new paints reduced energy needed for cooling by almost 21% in artificial warm conditions and reduced energy used for heating by about 36% in experiments using artificial cold environments.
How does this cooling paint tech work? Experts say that current low-emissivity paints usually have a grey or metallic silver colour, which limits their use in terms of aesthetics. This newly invented cooling paint has two layers that are applied separately. The first layer is an infrared reflective bottom layer using aluminium flakes, and the second layer is an ultrathin, infrared transparent upper layer that uses inorganic nanoparticles that come in a wide range of colours.
Most of the infrared light passes through the top colour layer and is reflected back off the lower layer, passing back out as light and not absorbing into the RV walls and roof as heat.
To keep the heat out and use it as a cooling paint, you apply it on exterior walls and roofs. To do the opposite and keep the heat inside, the paint is applied to interior walls where, again, the lower layer reflects the invisible infrared waves that transfer energy across space. According to the research team, up to 80% of high mid-infrared light is reflected by the cooling paint, which they tested in white, blue, red, yellow, green, orange, purple and dark grey.
Fancy a bright orange RV, anyone?
Researchers at America’s Purdue University have developed a different kind of revolutionary cooling paint that reportedly cools outdoor surfaces more than 4.5oC below the ambient temperature. Dubbed ‘the world’s whitest paint’, it uses barium sulphate nanoparticles to reflect 98.1% of sunlight. In comparison, regular commercial white paint gets warmer rather than cooler when subjected to sunlight, reflecting only 80% – 90% of the sunlight.
The cooling paint, developed by Purdue Professor of Mechanical Engineering Xiulin Ruan, originally had to be applied at least 0.4mm thick to achieve sub-ambient cooling, making it no good in an RV application due to the weight. However, in 2022, Ruan and his team further innovated by developing a new formula that is now thinner and lighter, achieving similar cooling with a layer of just 0.15mm thick.
This new cooling paint formulation incorporates hexagonal boron nitride as the pigment and, while weighing 80% less than the original formula, achieves a solar reflectance of 97.9% with a single layer of paint.
As that the paint absorbs less heat from the sun than it emits, a surface coated with this cooling paint is cooled below the surrounding temperature without consuming power. According to Ruan and his team’s models, covering 1% of the Earth’s surface in their technology could mitigate the total effects of global warming. As a result, they are now pursuing formulas suitable for surfaces like asphalt and roadways.
So, will we soon be able to ditch the RV air conditioning? My guess is eventually, but not anytime soon.
