'Super-white' paint to cool buildings
Marie Donlon | October 26, 2020Researchers from Purdue University have developed a “super-white” paint that is capable of cooling surfaces to roughly 18° F cooler than surrounding ambient temperatures.
According to its developers, the paint absorbs virtually no solar energy, reflecting 95.5% sunlight and radiating infrared heat from the painted surface.
During testing, researchers took infrared camera images of a sample of the super-white paint, which had been placed on a rooftop alongside a sample of commercial white paint. The Purdue team determined that the temperature of the super-white paint sample was lower than its surroundings and that of the standard white paint sample.
Used on buildings, the paint could one day reduce reliance on air conditioning, according to its developers.
For more information about the paint, watch the accompanying video that appears courtesy of Purdue University.
Yeah, how much does it cost? ....and how long does it last? Because if it costs several thousand dollars to paint your roof and it needs to be repainted every 5 years, well that's not so good ....
In reply to #1
I might add that 18°F is not that much if the roof is 136°F = 118°F
So they don't say what the temperature is that is dropping 18°F, and if it effects heat gain then what about in the winter time when you do want to gain heat, heating is more expensive than cooling.....The true test is how much it drops the indoor temperature on a hot day...not the roof temperature...You might have R-30 insulation in the attic, and the roof temperature only has a slight effect...
No I don't think this will replace air conditioning, might reduce the cost of cooling the crib a bit though, but it would have to be cheap....
Do you have a link to the published research?
However, Infrared cameras depend on the emissivity of the material to obtain a proper temperature as well as coupling to the reflected energy which is dependent on the roughness of the surface.
Perhaps useful for tropics that do not need to heat buildings at all .
However, the point about its cost is well taken . A lead acid battery versus a Li Ion battery is at least 2.5 times as costly with life approximately the same high in ratio, without taking the interest costs, that are palpably higher in developing countries .
Cost versus efficiency is OK for Developing countries but not for capital starved poorer countries .
In reply to #4
Maybe this paint is, but its albedo is similar to older products, and they're just getting extreme diminishing returns until they reach some sort of "vanta-white" or something. As part of its Cool Roofs initiative to reduce the load on the grid during the summer, New York City painted 1 million square feet of roofs with spray paint for hydro dipping similarly high albedo white paint in 20019.